This article records new taxa of fossil

archosaur Archosauria () is a clade of diapsids, with birds and crocodilians as the only living representatives. Archosaurs are broadly classified as reptiles, in the cladistic sense of the term which includes birds. Extinct archosaurs include non-avian d ...

s of every kind that are scheduled described during the year 2021, as well as other significant discoveries and events related to paleontology of archosaurs that are scheduled to occur in the year 2021.

General research

* A study on the relationship between full potential joint mobility and the poses used during locomotion in extant American alligator and helmeted guineafowl, evaluating its implications for reconstructions of locomotion of extinct archosaurs, is published by Manafzadeh, Kambic & Gatesy (2021). * A study on the femoral shape variation and on the relationship between femoral morphology and locomotor habits in early archosaurs and non-archosaur

archosauriforms Archosauriformes (Greek for 'ruling lizards', and Latin for 'form') is a clade of diapsid reptiles that developed from archosauromorph ancestors some time in the Latest Permian (roughly 252 million years ago). It was defined by Jacques Gauthi ...

is published by Pintore ''et al.'' (2021). * A study estimating moment arms for major

pelvic The pelvis (plural pelves or pelvises) is the lower part of the trunk, between the abdomen and the thighs (sometimes also called pelvic region), together with its embedded skeleton (sometimes also called bony pelvis, or pelvic skeleton). The ...

limb muscles in extant and fossil archosaurs, aiming to investigate the idea that bird-line archosaurs switched from hip-based to knee-based locomotion between Archosauria (especially Neotheropoda) and Aves, is published by Allen, Kilbourne & Hutchinson (2021). * A study aiming to determine how ontogenetic changes in skeletal anatomy influence muscle size, leverage, orientation, and locomotor function during the development of flight in extant chukar partridge is published by Heers ''et al.'' (2021), who evaluate the implications of their findings on current knowledge of how extinct winged theropods might have achieved bird-like behaviors before acquiring fully bird-like anatomies. * A study on jumping mechanics and performance in extant

elegant crested tinamou The elegant crested tinamou or martineta tinamou (''Eudromia elegans'') is a medium-sized tinamou that can be found in southern Chile and Argentina in Shrubland. The bird has an omnivorous diet. This species is terrestrial due to their poor flyi ...

, and on its implications for inferences of jumping abilities in extinct animals such as

dromaeosaurid Dromaeosauridae () is a family of feathered theropod dinosaurs. They were generally small to medium-sized feathered carnivores that flourished in the Cretaceous Period. The name Dromaeosauridae means 'running lizards', from Greek ('), meaning ...

dinosaurs, is published by Bishop ''et al.'' (2021). * A study on the morphological diversity and evolution of the semicircular canals of the inner ear in extant and fossil archosaurs is published by Bronzati ''et al.'' (2021). * A study on the evolution of eggshell thickness in non-avian dinosaurs and birds is published by Legendre &

Clarke Clarke is a surname which means "clerk". The surname is of English and Irish origin and comes from the Latin . Variants include Clerk and Clark. Clarke is also uncommonly chosen as a given name. Irish surname origin Clarke is a popular surname i ...

(2021). * A study on the evolution of birdlike locomotor abilities and hearing acuity, as indicated by the anatomy of the inner ear in extant and fossil reptiles and birds, is published by Hanson ''et al.'' (2021); the conclusions of the study are subsequently contested by David, Bronzati & Benson (2022). * A study assessing the accuracy of bite force estimates in extinct archosaurs and mammals is published by Sakamoto (2021). * A study on the composition of the assemblage of isolated archosaur (dinosaur and crocodyliform) teeth and osteoderms from the Upper Cretaceous

Cerro Fortaleza Formation The Cerro Fortaleza Formation, in older literature described as Pari Aike Formation, is a Late Cretaceous geologic formation of Campanian to Maastrichtian age (although it has formerly been reported to be Cenomanian to Santonian)Varela et al., 20 ...

( Argentina), and on its implications for the knowledge of the archosaur biodiversity in southern Patagonia during the Late Cretaceous, is published by Paulina-Carabajal ''et al.'' (2021). * A study on evolution of the expression of

carotenoid Carotenoids (), also called tetraterpenoids, are yellow, orange, and red organic compound, organic pigments that are produced by plants and algae, as well as several bacteria, and Fungus, fungi. Carotenoids give the characteristic color to pumpki ...

s in skin and other integumentary structures of archosaurs is published by Davis & Clarke (2021). * A study on the ossification patterns of the respiratory turbinate in extant birds, and on their implications for the identification of the positions and form of possible osteological correlates of the respiratory turbinate in non-avian dinosaurs, is published by Tada & Tsuihiji (2021). * Revision of the Mesozoic and Cenozoic record of large, unwebbed bird and bird-like footprints is published by Lockley, Abbassi & Helm (2021).

Pseudosuchians

Crocodylomorphs

Crocodylomorph research

* A study on the morphological diversity of skull and jaw shape in

crocodylomorphs Crocodylomorpha is a group of pseudosuchian archosaurs that includes the crocodilians and their extinct relatives. They were the only members of Pseudosuchia to survive the end-Triassic extinction. During Mesozoic and early Cenozoic times, cr ...

throughout their evolutionary history is published by Stubbs ''et al.'' (2021). * A study on the evolution of the skull morphology in crocodyliforms is published by Felice, Pol & Goswami (2021). * A study on the anatomy, phylogenetic relationships and stratigraphy of the holotype specimen of ''

Notochampsa ''Notochampsa'' is an extinct genus of protosuchian crocodylomorph. Fossils have been found from the lower Clarens Formation of the Karoo Supergroup in South Africa, dating back to the Pliensbachian stage of the Early Jurassic. ''Notochampsa'' c ...

istedana'' is published by Dollman ''et al.'' (2021). * A study on the skull anatomy and phylogenetic placement of ''

Eopneumatosuchus ''Eopneumatosuchus'' is an extinct genus of basal crocodyliform. Fossils have been found from two localities within the Kayenta Formation of Arizona. Both localities are around 20 miles southeast of the Grand Canyon and in close proximity to on ...

colberti'' is published by Melstrom, Turner & Irmis (2021). * A study on the bite force in

mesoeucrocodylia Mesoeucrocodylia is the clade that includes Eusuchia and crocodyliforms formerly placed in the paraphyletic group Mesosuchia. The group appeared during the Early Jurassic, and continues to the present day. Diagnosis It was long known that M ...

ns throughout their evolutionary history is published by Gignac, Smaers & O'Brien (2021). * A study on feeding habits of notosuchians from the Upper Cretaceous Bauru Group ( Brazil), as indicated by stable carbon and oxygen isotope data from tissues of notosuchians from two sites from Bauru Group, is published by Klock ''et al.'' (2021). * Description of coprolites from the Upper Cretaceous

Adamantina Formation The Adamantina Formation is a geological formation in the Bauru Basin of western São Paulo state, in southeastern Brazil. Its strata date back to the Late Cretaceous epoch of the Cretaceous Period, during the Mesozoic Era. The formation is p ...

( Brazil) found in association with skeletons of

baurusuchid Baurusuchidae is a Gondwanan Family (biology), family of mesoeucrocodylians that lived during the Late Cretaceous. It is a group of terrestrial hypercarnivorous crocodilians from South America (Argentina and Brazil) and possibly Pakistan. Baurusu ...

and

sphagesaurid Sphagesauridae is a Gondwanan family of mesoeucrocodylians that lived during the Late Cretaceous. It was a clade of terrestrial crocodilians that evolved very mammal-like teeth and jaws.MARINHO, T.S. & CARVALHO, I.S. Revision of the Sphagesaurida ...

crocodylomorphs, and a study on the implications of these coprolites for the knowledge of the diet of these crocodylomorphs, is published by de Oliveira ''et al.'' (2021). * A study on the morphological variation in the dentition of uruguaysuchid crocodylomorphs is published by Figueiredo &

Kellner Kellner is a surname. Notable people with the surname include: * Ádám Kellner (born 1986), Hungarian tennis player * Alex Kellner (1924–1996), baseball pitcher * Alexander Kellner (born 1961), Brazilian paleontologist * Birgit Kellner, Austria ...

(2021). * A study on the bone histology and growth dynamics of '' Araripesuchus'', based on data from specimens from the La Buitrera Palaeontological Area ( Río Negro Province, Argentina), is published by Fernández Dumont ''et al.'' (2021). * A study on the resistance to stress of the skull of ''Araripesuchus gomesii'', and on its implications for the knowledge of likely diet of this crocodylomorph, is published by Nieto ''et al.'' (2021). * New partially preserved skull of ''

Campinasuchus ''Campinasuchus'' is an extinct genus of baurusuchid mesoeucrocodylian from Minas Gerais State of Brazil. Description ''Campinasuchus'', like other baurusuchids, was a fully terrestrial predator. It had a deep and laterally compressed skull wi ...

dinizi'' is described from the Fazenda São José (Adamantina/Vale do Rio do Peixe Formation, Brazil) by Darlim ''et al.'' (2021), who evaluate the implications of this specimen for the knowledge of the distribution of

baurusuchids Baurusuchidae is a Gondwanan family of mesoeucrocodylians that lived during the Late Cretaceous. It is a group of terrestrial hypercarnivorous crocodilians from South America (Argentina and Brazil) and possibly Pakistan. Baurusuchidae has been, i ...

in the Late Cretaceous of South America. * The first known baurusuchid yearling is described from the

( Brazil) by dos Santos ''et al.'' (2021). * New baurusuchid specimen, providing new information on the skeletal growth in baurusuchids, is described from the Upper Cretaceous

(Brazil) by Marchetti ''et al.'' (2021). * A study on the anatomy of the endocranial structures of '' Zulmasuchus querejazus'', and on its implications for the knowledge of the head posture, hearing capabilities and likely lifestyle of this sebecid, is published by Pochat-Cottilloux ''et al.'' (2021). * New soft tissue records for thalattosuchians are reported from the Late Jurassic localities of Wattendorf and Painten (Bavaria, Germany) by Spindler ''et al.'' (2021), who interpret their findings as indicating the skin of

metriorhynchids Metriorhynchidae is an extinct family of specialized, aquatic metriorhynchoid crocodyliforms from the Middle Jurassic to the Early Cretaceous period (Bajocian to early Aptian) of Europe, North America and South America. The name Metriorhync ...

lacked any traces of scales or scutes and instead showed folded and transverse fibers. * A study on the nasal and paranasal anatomy of thalattosuchians, and on its implications for the knowledge of the evolution of the paranasal sinus system and nasopharyngeal ducts in Thalattosuchia, is published by Cowgill ''et al.'' (2021). * Description of the cranial and endocranial anatomy of ''

Macrospondylus ''Macrospondylus'' is an extinct genus of machimosaurid teleosauroid crocodyliform from the Early Jurassic (Toarcian) of Europe. Fossils are known from the Posidonia Shale of Germany, the Whitby Mudstone of the United Kingdom, and the "''schist ...

bollensis'' is published by Wilberg ''et al.'' (2021). * A study on the innervation of the rostrum of

metriorhynchoid Metriorhynchoidea is an extinct superfamily of thalattosuchian crocodyliforms from the Early Jurassic to the Early Cretaceous (Toarcian - Valanginian, possibly as late as early Aptian) of Europe, North America and South America. Metriorhynch ...

thalattosuchians, and on its implications for the knowledge of the somatosensory abilities of these crocodylomorphs, is published by Bowman ''et al.'' (2021). * Isolated metriorhynchid tooth crowns, representing some of the most recent known occurrences of Metriorhynchidae worldwide, are described from the Valanginian Kopřivnice Formation ( Czech Republic) by Madzia ''et al.'' (2021), who interpret these specimens as evidence of the presence of two distinct lineages of geosaurin metriorhynchids in the area of Czech Republic during the

Early Cretaceous The Early Cretaceous ( geochronological name) or the Lower Cretaceous (chronostratigraphic name), is the earlier or lower of the two major divisions of the Cretaceous. It is usually considered to stretch from 145 Ma to 100.5 Ma. Geology Pro ...

. * A study on the anatomy of the braincase of a metriorhynchid specimen belonging or related to the species ''" Metriorhynchus" brachyrhynchus'', and on the evolution of neurosensory and endocranial systems of metriorhynchids, is published by Schwab ''et al.'' (2021). * A study on the anatomy of the snout of '' Dakosaurus andiniensis'', and on the evolution of the facial anatomy of thalattosuchians, is published by Fernández & Herrera (2021), who interpret their findings as indicative of presence of anatomical adaptations likely helping drainage of nasal glands (probably excreting salt). * A study on histology and stable isotope geochemistry of the fossil material of ''

Goniopholis ''Goniopholis'' (meaning "angled scale") is an extinct genus of goniopholidid crocodyliform that lived in Europe and Africa during the Late Jurassic and Early Cretaceous. Being semi-aquatic it is very similar to modern crocodiles. It ranged from ...

'' and ''

Dyrosaurus ''Dyrosaurus'' is a genus of extinct crocodylomorph that lived during the early Eocene. The name ''Dyrosaurus'' comes from () the Greek for lizard or reptile, and Dyr for Djebel Dyr (mountain) close to where the type species was discovered. It ...

'', and on their implications for the knowledge whether these crocodylomorphs were ectotherms or endotherms, is published by Faure-Brac ''et al.'' (2021). * A study on the evolution of

tethysuchia Tethysuchia is an extinct clade of neosuchian mesoeucrocodylian crocodylomorphs from the late Middle Jurassic (Bathonian stage) to the Early Eocene (Ypresian stage) of Asia, Europe, North America and South America. It was named by the French ...

n and

gavialoid Gavialoidea is one of three superfamilies of crocodylians, the other two being Alligatoroidea and Crocodyloidea. Although many extinct species are known, only the gharial ''Gavialis gangeticus'' and the false gharial ''Tomistoma schlegelii'' are ...

crocodylomorphs from the Campanian to the Thanetian is published by Jouve (2021). * A study on the histology of the humeri and femora of '' Hyposaurus rogersii'' is published by Pellegrini ''et al.'' (2021). * A study on the anatomy of the braincase and inner ear of ''

Rhabdognathus ''Rhabdognathus'' is an extinct genus of dyrosaurid crocodylomorph. It is known from rocks dating to the Paleocene epoch from western Africa, and specimens dating back to the Maastrichtian era were identified in 2008. It was named by Swinton in 1 ...

aslerensis'' is published by Erb & Turner (2021). * A study on the anatomy of the postcranial skeleton of '' Cerrejonisuchus improcerus'' is published by Scavezzoni & Fischer (2021), who also provide new information on the anatomy of the postcranial skeletons of ''

Congosaurus ''Congosaurus'' is an extinct genus of dyrosaurid mesoeucrocodylian. Fossils have been found from Lândana, in Angola and date back to the Paleocene epoch. In 1952 and 1964 ''Congosaurus'' was proposed to be synonymous with ''Dyrosaurus''. The g ...

bequaerti'' and '' Hyposaurus rogersii'', and provide evidence of a distinctive postcranial anatomy of

dyrosaurids Dyrosauridae is a family of extinct neosuchian crocodyliforms that lived from the Late Cretaceous (Maastrichtian) to the Eocene. Dyrosaurid fossils are globally distributed, having been found in Africa, Asia, Europe, North America and South Amer ...

among crocodyliforms. * New fossil material of '' Deltasuchus motherali'', providing new information on changes in the skeleton of this crocodyliform during the ontogeny, and indicative of dietary shifts from juvenile to adult, is described from the

Cenomanian The Cenomanian is, in the ICS' geological timescale, the oldest or earliest age of the Late Cretaceous Epoch or the lowest stage of the Upper Cretaceous Series. An age is a unit of geochronology; it is a unit of time; the stage is a unit in the s ...

Woodbine Formation The Woodbine Group is a geological formation in east Texas whose strata date back to the Early to Middle Cenomanian age of the Late Cretaceous. It is the producing formation of the giant East Texas Oil Field (also known as the "Black Giant") from ...

( Texas, United States) by Drumheller ''et al.'' (2021), who also study the phylogenetic relationships of ''D. motherali'', and identify an endemic clade of Appalachian crocodyliforms, which they name Paluxysuchidae. * Redescription and a study on the phylogenetic relationships of ''

Duerosuchus ''Duerosuchus'' is an extinct genus of crocodilian. Remains have been found from Corrales del Vino in Zamora, Spain, and are middle Eocene in age (about 40 million years old). ''Duerosuchus'' is known from a single skull that is incomplete but ...

piscator'' is published by Narváez ''et al.'' (2021). * A study on the phylogenetic relationships and the evolutionary history of crocodilians is published by Rio & Mannion (2021). * New fossil material of '' Deinosuchus'', representing one of the earliest records of this genus in North American reported to date, is described from the Campanian Menefee Formation (New Mexico, United States) by Mohler, McDonald & Wolfe (2021). * Description of the crocodyliform fossil material from the Eocene ( Lutetian) Ikovo locality ( Ukraine), including the easternmost record of diplocynodontines in Europe reported to date, is published by Kuzmin & Zvonok (2021), who also review the fossil record and

biogeography Biogeography is the study of the distribution of species and ecosystems in geographic space and through geological time. Organisms and biological communities often vary in a regular fashion along geographic gradients of latitude, elevation, ...

of crocodyliforms from the Paleocene and Eocene of Europe. * Description of additional fossil material of ''

Tsoabichi ''Tsoabichi'' is an extinct genus of caimanine crocodylian. Fossils are known from the Green River Formation in Wyoming, and date back to the Ypresian stage of the Eocene (Wasatchian stage of North American age). The genus was named and describ ...

greenriverensis'' from the Eocene Green River Formation, providing further evidence for its caimanine affinities, and a study on the evolutionary history of caimanines is published by Walter ''et al.'' (2021). * Cidade & Rincón (2021) report the first occurrence of '' Acresuchus pachytemporalis'' from the Miocene

Urumaco Urumaco is a town in Falcón State in Venezuela. It is of interest to paleontologists due to its rich fossil history. The arid climate of the region means that the fossils are not hidden by vegetation. The fossils were first made known to scienc ...

Formation ( Venezuela), expanding known geographic distribution of this species. * Description and a study on the taxonomic status of the crocodylians from the

Neogene The Neogene ( ), informally Upper Tertiary or Late Tertiary, is a geologic period and system that spans 20.45 million years from the end of the Paleogene Period million years ago ( Mya) to the beginning of the present Quaternary Period Mya. ...

Irrawaddy Formation (

Myanmar Myanmar, ; UK pronunciations: US pronunciations incl. . Note: Wikipedia's IPA conventions require indicating /r/ even in British English although only some British English speakers pronounce r at the end of syllables. As John C. Wells, Joh ...

), including one of the oldest records of the genus ''

Gavialis ''Gavialis'' is a genus of crocodylians that includes the living gharial ''Gavialis gangeticus'' and one known extinct species, '' Gavialis bengawanicus.'' ''G. gangeticus'' comes from the Indian Subcontinent, while ''G. bengawanicus'' is known ...

'' reported to date, is published by Iijima ''et al.'' (2021). * Revision of the taxonomy and a study on the phylogenetic relationships of the Miocene

tomistomines Tomistominae is a subfamily of crocodylians that includes one living species, the false gharial. Many more extinct species are known, extending the range of the subfamily back to the Eocene epoch. In contrast to the false gharial, which is a fre ...

from Italy and Malta is published by Nicholl ''et al.'' (2021). * A study on the phylogenetic relationships of '' Voay robustus'', based on mitochondrial genomic data, is published by Hekkala ''et al.'' (2021). * Description of a new skull of ''

Crocodylus anthropophagus ''Crocodylus anthropophagus'' is an extinct species of crocodile from the Pleistocene of Tanzania. It lived 1.84 million years ago. It was a large-sized predator reaching a length of . Etymology ''Crocodylus anthropophagus'' was first named by ...

'' from the DK site at Olduvai ( Tanzania), representing the oldest fossil of a member of this species reported to date, and a study on the phylogenetic relationships of this species is published by Azzarà ''et al.'' (2021)

Aetosaur research

* Description of the braincase of '' Aetosauroides scagliai'', based on data from specimens from the Upper Triassic Candelária Sequence ( Brazil), is published by Paes Neto ''et al.'' (2021). * Description of the skull ''Aetosauroides scagliai'', and a study on the likely diet and paleobiology of this aetosaur, is published by Paes Neto ''et al.'' (2021). * A study on the anatomy of the axial skeleton of ''Aetosauroides'' is published by Paes-Neto ''et al.'' (2021), who propose that ''Polesinesuchus aurelioi'' is a

junior synonym The Botanical and Zoological Codes of nomenclature treat the concept of synonymy differently. * In botanical nomenclature, a synonym is a scientific name that applies to a taxon that (now) goes by a different scientific name. For example, Linna ...

of ''Aetosauroides scagliai''. * An incomplete, largely articulated postcranial skeleton of a

basal Basal or basilar is a term meaning ''base'', ''bottom'', or ''minimum''. Science * Basal (anatomy), an anatomical term of location for features associated with the base of an organism or structure * Basal (medicine), a minimal level that is nec ...

aetosaur, possibly distinct from ''Aetosauroides scagliai'', and preserving anatomical features which aren't often preserved in aetosaur specimens (including extensive appendicular armor and a well-preserved caudal ventral carapace), is described from the Upper Triassic

Ischigualasto Formation The Ischigualasto Formation is a Late Triassic fossiliferous formation and Lagerstätte in the Ischigualasto-Villa Unión Basin of the southwestern La Rioja Province and northeastern San Juan Province in northwestern Argentina. The formation da ...

( Argentina) by Hecket, Martínez & Celeskey (2021). * An osteoderm of ''

Typothorax ''Typothorax'' is an extinct genus of typothoracine aetosaur that lived in the Late Triassic. Its remains have been found in North America. Two species are known: ''T. coccinarum'', the type species, and ''T. antiquum''. Description ''Typothor ...

coccinarum'' with punctures and scores which are likely bite marks is described from the Upper Triassic Chinle Formation ( Arizona, United States) by Drymala, Bader & Parker (2021), who interpret this finding as supporting the hypothesis that aetosaurs were prey items of large

archosauromorphs Archosauromorpha ( Greek for "ruling lizard forms") is a clade of diapsid reptiles containing all reptiles more closely related to archosaurs (such as crocodilians and dinosaurs, including birds) rather than lepidosaurs (such as tuataras, lizard ...

. * Reyes, Parker & Marsh (2021) describe the first complete articulated skull of ''Typothorax coccinarum'' from the Owl Rock Member of the Chinle Formation (

Petrified Forest National Park Petrified Forest National Park is an American national park in Navajo County, Arizona, Navajo and Apache County, Arizona, Apache counties in northeastern Arizona. Named for its large deposits of petrified wood, the park covers about , encompassin ...

), and evaluate the implications of this specimen for the knowledge of the relationships and morphological diversity of aetosaurs. * A study on the biomechanical properties of the skull of '' Neoaetosauroides engaeus'' is published by Taborda, Desojo & Dvorkin (2021). * Revision of isolated braincases of '' Desmatosuchus'' from the ''Placerias'' Quarry locality in the

Chinle Formation The Chinle Formation is an Upper Triassic continental geological formation of fluvial, lacustrine, and palustrine to eolian deposits spread across the U.S. states of Nevada, Utah, northern Arizona, western New Mexico, and western Colorado. In Ne ...

( Arizona, United States) is published by von Baczko ''et al.'' (2021), who report the presence of two species of ''Desmatosuchus'' (''D. spurensis'' and ''D. smalli'') at the ''Placerias'' Quarry.

General pseudosuchian research

* A study on the phylogenetic relationships of pseudosuchian archosaurs, aiming to determine drivers of body size evolution in this group, is published by Stockdale &

Benton Benton may refer to: Places Canada *Benton, a local service district south of Woodstock, New Brunswick *Benton, Newfoundland and Labrador United Kingdom * Benton, Devon, near Bratton Fleming * Benton, Tyne and Wear United States *Benton, Alabam ...

(2021); the study is subsequently criticized by Benson ''et al.'' (2022). * The first occurrence of the track type ''"

Chirotherium ''Chirotherium'', also known as ''Cheirotherium'' (‘hand-beast’), is a Triassic trace fossil consisting of five-fingered (pentadactyle) footprints and whole tracks. These look, by coincidence, remarkably like the hands of apes and bears, with ...

" lulli'' (inferred to be produced by a pseudosuchian archosaur) from western North America is reported from the Owl Rock Member of the

( Utah, United States) by Milner ''et al.'' (2021). * A study on the skeletal anatomy and phylogenetic relationships of '' Revueltosaurus callenderi'' is published by Parker ''et al.'' (2021). * A study on the skull anatomy and likely feeding habits of '' Effigia okeeffeae'' is published by Bestwick ''et al.'' (2021).

Non-avian dinosaurs

Research

General

* A study on the impact of the disparity between neonates and adults on the structure and diversity of dinosaur communities is published by Schroeder, Lyons & Smith (2021), who claim that communities with giant theropods lacked carnivores weighing 100 to 1000 kg, and argue that juveniles of giant theropod species likely filled the mesocarnivore niche, resulting in reduced overall taxonomic diversity; their conclusions are subsequently contested by Benson ''et al.'' (2022). * Evidence of cessation of longitudinal skeletal growth in non-avian dinosaurs, inferred from a study of the articular surfaces of long bones, is presented by Rothschild & Witzmann (2021). * A study aiming to determine the

survivorship curve A survivorship curve is a graph showing the number or proportion of individuals surviving to each age for a given species or group (e.g. males or females). Survivorship curves can be constructed for a given cohort (a group of individuals of roughly ...

s of '' Albertosaurus sarcophagus'', '' Gorgosaurus libratus'', ''

Daspletosaurus ''Daspletosaurus'' ( ; meaning "frightful lizard") is a genus of tyrannosaurid dinosaur that lived in Laramidia between about 79.5 and 74 million years ago, during the Late Cretaceous Period. The genus ''Daspletosaurus'' contains three species ...

torosus'', '' Tyrannosaurus rex'', ''

Maiasaura ''Maiasaura'' (from the Greek ''μαῖα'', meaning "good mother" and ''σαύρα'', the feminine form of ''saurus'', meaning "reptile") is a large herbivorous saurolophine hadrosaurid ("duck-billed") dinosaur genus that lived in the area curre ...

peeblesorum'' and '' Psittacosaurus lujiatuensis'' in populations with an age distribution which was stable in shape over time is published by Griebeler (2021). * A study aiming to determine whether the presence of

keratan sulfate Keratan sulfate (KS), also called keratosulfate, is any of several sulfated glycosaminoglycans (structural carbohydrates) that have been found especially in the cornea, cartilage, and bone. It is also synthesized in the central nervous system w ...

is exclusive evidence for the presence of

medullary bone The medullary cavity (''medulla'', innermost part) is the central cavity of bone shafts where red bone marrow and/or yellow bone marrow (adipose tissue) is stored; hence, the medullary cavity is also known as the marrow cavity. Located in the ma ...

in dinosaur fossils (and therefore whether it can be used to identify dinosaur specimens as gravid females) is published by Canoville ''et al.'' (2021). * A study on the variation in tail anatomy and length across the Dinosauria is published by Hone, Persons & Le Comber (2021). * A study on the possibilities of determination of the presence of sexual dimorphism in dinosaurs, evaluating whether the previous method used for dinosaurs correctly recognizes living animals as dimorphic, is published by Motani (2021). * A study on the role of climate in shaping the geographic distribution of Mesozoic dinosaurs is published by Chiarenza ''et al.'' (2021). * Review of the fossil record of Carnian dinosaurs from South America is published by Novas ''et al.'' (2021), who also interpret '' Chindesaurus'', '' Daemonosaurus'' and '' Tawa'' as likely late-surviving members of Herrerasauria. * A study on dinosaur trackways that show changes in direction from Jurassic and Cretaceous sites in North and South America, Europe and Asia is published by Lockley ''et al.'' (2021). * Fossil trackways made by theropods, ornithopods and possibly

ankylosaurs Ankylosauria is a group of herbivorous dinosaurs of the order Ornithischia. It includes the great majority of dinosaurs with armor in the form of bony osteoderms, similar to turtles. Ankylosaurs were bulky quadrupeds, with short, powerful limbs. ...

, are reported from the Folkestone Formation of the Lower Greensand Group by Hadland ''et al'' (2021), representing the youngest known footprints of non-avian dinosaurs known from the United Kingdom. * A study on the climate of the Lufeng area (

China China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's most populous country, with a population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones and ...

) during the Early Jurassic, and on the relationship between the global distribution of dinosaur fossils and climate during the Jurassic, is published by Shen ''et al.'' (2021). * A study on the relationships between diet, tooth complexity and tooth replacement rates in Late Jurassic dinosaurs is published by Melstrom,

Chiappe Chiappe is a surname. Notable people with the surname include: *Luis M. Chiappe, Argentine paleontologist *Jean Chiappe, high-ranking French civil servant *María Luisa Chiappe, Colombian economist, diplomat, civil servant and businesswoman *Sandro ...

& Smith (2021). * Description of the fossil material of a tyrannosauroid theropod and an early member of the family Hadrosauridae from the Upper Cretaceous

Merchantville Formation The Merchantville Formation is a geological formation in the northeastern United States whose strata date back to the Late Cretaceous, around the time of the Santonian and Campanian age. Dinosaur remains are among the fossils that have been recove ...

( Delaware and New Jersey, United States), possibly representing new taxa, and a study on the phylogenetic affinities of these dinosaurs is published by Brownstein (2021). * Druckenmiller ''et al.'' (2021) report the discovery of a diverse assemblage of herbivorous and carnivorous non-avian dinosaurs, including perinatal and very young specimens, from the Upper Cretaceous Prince Creek Formation ( Alaska, United States), and interpret this finding as indicating that most, if not all, dinosaurs from this assemblage were nonmigratory year-round Arctic residents. * A study on the distribution of dinosaurs across the latest Cretaceous of North America is published by García‐Girón ''et al.'' (2021). * A study aiming to determine whether plant-eating dinosaurs could have moved seeds long distances is published by Perry (2021). * Dinosaur tracks with elongated metatarsal marks and superficially human-like appearance are interpreted by Lallensack, Farlow & Falkingham (2021) as more likely to be caused by deep penetrations of the foot in soft sediment than by a

plantigrade 151px, Portion of a human skeleton, showing plantigrade habit In terrestrial animals, plantigrade locomotion means walking with the toes and metatarsals flat on the ground. It is one of three forms of locomotion adopted by terrestrial mammals. T ...

mode of locomotion. * A study on changes of diversity of dinosaurs belonging to the families Ankylosauridae, Ceratopsidae,

Hadrosauridae Hadrosaurids (), or duck-billed dinosaurs, are members of the ornithischian family Hadrosauridae. This group is known as the duck-billed dinosaurs for the flat duck-bill appearance of the bones in their snouts. The ornithopod family, which includ ...

, Dromaeosauridae, Troodontidae and Tyrannosauridae during the Late Cretaceous is published by Condamine ''et al.'' (2021), who interpret their findings as indicative of a decline of non-avian dinosaur diversity during the last 10 million years of the Cretaceous period, and attempt to determine possible causes of this decline. * The study published by Bonsor ''et al.'' (2020), aiming to determine whether non-avian dinosaurs were in long-term decline prior to the Cretaceous–Paleogene extinction event, is criticized by Sakamoto,

& Venditti (2021). * A study on a dinosaur nesting site preserved in the Upper Cretaceous Wido Volcanics ( Wi Island, South Korea) is published by Kim ''et al.'' (2021; final version published in 2022), providing new information on how these dinosaurs chose their nesting sites.

Saurischians

* New fossil material of theropod and sauropod dinosaurs, including a caudal vertebra with

pneumatic Pneumatics (from Greek ‘wind, breath’) is a branch of engineering that makes use of gas or pressurized air. Pneumatic systems used in Industrial sector, industry are commonly powered by compressed air or compressed inert gases. A central ...

internal structures rarely observed outside Late Cretaceous South American saltasaurines, is described from the Campanian

Quseir Formation The Quseir Formation is a geological formation in the vicinity of the Kharga Oasis in Egypt.

( Egypt) by Salem ''et al.'' (2021). * Evidence indicating that some mid-sized dendroolithid eggs were laid by a

therizinosauroid Therizinosaurs (once called segnosaurs) were large herbivorous theropod dinosaurs whose fossils have been found across the Early to Late Cretaceous deposits in Asia and North America. Various features of the forelimbs, skull and pelvis unite thes ...

theropod is presented by Kundrát & Cruickshank (2021), who also report the discovery of putative embryonic remains (possibly of a titanosaur sauropod) in a faveoloolithid egg. * Putative large-sized sauropodomorph specimen from the Carnian strata at the 'Cerro da Alemoa' locality (southern Brazil) is reinterpreted as a

herrerasaurid Herrerasauridae is a family of carnivorous dinosaurs, possibly basal to either theropods or even all of saurischians, or even their own branching from dracohors, separate from dinosauria altogether. They are among the oldest known dinosaurs, fi ...

specimen (the largest dinosaur reported from the Candelária Sequence to date) by Garcia ''et al.'' (2021). * Putative tracks of a large-bodied predatory dinosaur from the Upper Triassic Blackstone Formation (

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

) are reinterpreted by Romilio ''et al.'' (2021) as sharing characteristics with the sauropodomorph ichnogenus '' Evazoum'', and possibly representing the first evidence of

sauropodomorph dinosaurs from Australia.

= Theropods

= * A study aiming to determine whether the knowledge of patterns of species abundance and clade diversity in theropod dinosaurs is significantly impacted by the diagnosability of their fossils is published by Cashmore,

Butler A butler is a person who works in a house serving and is a domestic worker in a large household. In great houses, the household is sometimes divided into departments with the butler in charge of the dining room, wine cellar, and pantry. Some a ...

& Maidment (2021). * A study on the evolution of vision and hearing modalities in theropod dinosaurs is published by Choiniere ''et al.'' (2021), who interpret their findings as indicative of early evolution of nocturnal predation in

alvarezsauroid Alvarezsauroidea is a group of small maniraptoran dinosaurs. Alvarezsauroidea, Alvarezsauridae, and Alvarezsauria are named for the historian Gregorio Álvarez, not the more familiar physicist Luis Alvarez, or his son geologist Walter Alvarez ...

theropods. * A study on changes of feeding mechanics of theropods throughout their evolutionary history is published by Ma ''et al.'' (2021). * Bishop ''et al.'' (2021) create three-dimensional simulations of gait in '' Coelophysis bauri'', and interpret their findings as indicative of a crucial and dynamic role of the tail in the locomotion of this theropod. * A vertebra of a non-

coelophysoid Coelophysoidea were common dinosaurs of the Late Triassic and Early Jurassic periods. They were widespread geographically, probably living on all continents. Coelophysoids were all slender, carnivorous forms with a superficial similarity to the ...

, non- averostran

neotheropod Neotheropoda (meaning "new theropods") is a clade that includes coelophysoids and more advanced theropod dinosaurs, and is the only group of theropods that survived the Triassic–Jurassic extinction event. All neotheropods became extinct by the ...

which may be 15 million years older than '' Dilophosaurus wetherilli'' is described from the Lower Jurassic (

Hettangian The Hettangian is the earliest age and lowest stage of the Jurassic The Jurassic ( ) is a Geological period, geologic period and System (stratigraphy), stratigraphic system that spanned from the end of the Triassic Period million years ago (My ...

) Whitmore Point Member of the Moenave Formation ( Utah, United States) by Marsh ''et al.'' (2021), who interpret this finding as indicating that not all contemporaneous theropod traces were made by coelophysoids. *

McMenamin McMenamin is an Irish surname. In Gaelic it is rendered, Mac Meanman, meaning 'son of Meanma' a name meaning courageous or high spirited. It originated in Co. Donegal in the 13th century. The first written mention of the name is in 1303 in the 'An ...

(2021) describes a humerus of a

from the

Portland Formation The Portland Formation is a geological formation in Connecticut and Massachusetts in the northeastern United States.Dilophosaurus'', and interpret it as a large piscovorous creature based on the locale's ecology. * An assemblage of over 100 theropod footprints of various size and morphology is described from the Lower Jurassic

Fengjiahe Formation The Fengjiahe Formation is a geological formation in China. It dates back to the Early Jurassic, most likely to the Pliensbachian. The formation is up to 1500 metres thick and consists of "purple-red mudstone and argillaceous siltstone interbedded ...

(China) by Li ''et al.'' (2021), representing the track site with the largest number of theropod footprints in Yunnan reported to date. * New fossil material of ceratosaur theropods, probably representing one of the oldest known record of abelisaurids, is described from the Upper Jurassic

Cañadón Calcáreo Formation The Cañadón Calcáreo Formation is an Oxfordian to Kimmeridgian-aged geologic formation, from the Cañadón Asfalto Basin in Chubut Province, Argentina, a rift basin that started forming since the earliest Jurassic.Figari et al., 2015, p.142 It ...

( Argentina) by Rauhut & Pol (2021). * A study on the skeletal anatomy and phylogenetic relationships of ''

Xenotarsosaurus ''Xenotarsosaurus'' is a genus of abelisaurid theropod dinosaur that lived during the Late Cretaceous of Argentina. Discovery In 1980 geologist Juan Carlos Sciutto discovered a rich fossil site six kilometres north of the Ocho Hermanos ranch in ...

bonapartei'' is published by Ibiricu ''et al.'' (2021). * Two new

furileusauria Furileusauria ("stiff back lizards") is an extinct clade of derived abelisaurid dinosaurs only known from South American fossil remains. They represent some of the largest members of the Abelisauridae, with an average length of . The clade is ...

n abelisaurid specimens from the

Santonian The Santonian is an age in the geologic timescale or a chronostratigraphic stage. It is a subdivision of the Late Cretaceous Epoch or Upper Cretaceous Series. It spans the time between 86.3 ± 0.7 mya (million years ago) and 83.6 ± 0.7 mya. The ...

Bajo de la Carpa Formation (Argentina), providing new information on the abundance of abelisaurids in this area and on variety of abelisaurid morphotypes that coexisted in the north of Argentine Patagonia during the Late Cretaceous, are described by Méndez ''et al.'' (2021; final version published in 2022). * Description of the preserved integument of '' Carnotaurus sastrei'' is published by Hendrickx & Bell (2021). * Revision of the phylogenetic affinities and evolutionary significance of '' Saltriovenator zanellai'' and '' Scipionyx samniticus'' is published by Cau (2021), who interprets his findings as raising doubts on the systematic status of theropod specimens assigned to the family Compsognathidae, which might turn out to be immature individuals belonging to various lineages of large-bodied

tetanurans Tetanurae (/ˌtɛtəˈnjuːriː/ or "stiff tails") is a clade that includes most theropod dinosaurs, including megalosauroids, allosauroids, tyrannosauroids, ornithomimosaurs, compsognathids and maniraptorans (including birds). Tetanurans ar ...

, with the holotype specimen of ''S. samniticus'' possibly being an immature carcharodontosaurid. * Two trackways belonging to fast-running theropods (probably

tetanurans) are described from the Lower Cretaceous

Enciso Group The Enciso Group is a geological formation in La Rioja, Spain whose strata date back to the Early Cretaceous.Spain) by Navarro-Lorbés ''et al.'' (2021), who present the speeds of locomotion calculated for both trackways, which are among the top speeds ever calculated for non-avian theropod tracks, and interpret one of the trackways as produced by a dinosaur with the ability to make and control substantial speed changes while running. *

Spinosaurid The Spinosauridae (or spinosaurids) are a clade or family of tetanuran theropod dinosaurs comprising ten to seventeen known genera. They came into prominence during the Cretaceous period. Spinosaurid fossils have been recovered worldwide, includi ...

neck vertebrae distinct from known vertebrae of '' Spinosaurus aegyptiacus'' and exhibiting an unusual combination of positionally variable characters are described from the Kem Kem Group ( Morocco) by McFeeters (2021), who interprets this finding as evidence of a greater degree of intraspecific variation in the vertebrae of ''S. aegyptiacus'' than previously recognized, or alternatively, evidence for the occurrence of two spinosaurid taxa in the Kem Kem Group. * Spinosaurid caudal vertebrae are described from the Lower Cretaceous

Sao Khua Formation The Sao Khua Formation () is a middle member of the Khorat Group. It consists of an alteration of pale red to yellowish-gray, fine to medium-grained sandstone and grayish-reddish brown siltstone and clay. Rare pale red to light gray conglomerates, ...

( Thailand) by Samathi, Sander & Chanthasit (2021), who also reinterpret the putative ceratosaur '' Camarillasaurus cirugedae'' as a spinosaurid. * A study on the diversity of the premaxillae shape in spinosaurids, an on its implications for the knowledge of the phylogenetic relationships of the spinosaurids, is published by Lacerda, Grillo & Romano (2021). * Hone &

Holtz Holtz is the surname of: * Alexander Holtz (born 2002), Swedish ice hockey player * Andrew Holtz, American journalist * Carl Holtz (1920–2006), American oarsman and farmer * Daniel Holtz, a fictional character on the TV series ''Angel'' * Eric H ...

(2021) evaluate the evidence for the competing interpretations of the ecology of '' Spinosaurus'', and reject the interpretation of this theropod as a specialised aquatic pursuit predator. * A study on the histology and geochemistry of a tibia and a femur of a specimen or specimens of '' Allosaurus fragilis'' from the Cleveland-Lloyd Dinosaur Quarry ( Utah, United States), and on its implications for the knowledge of the growth strategy of this species, is published by Ferrante ''et al.'' (2021). * Caudal vertebra of a theropod with affinities to

Carcharodontosauria Allosauroidea is a superfamily or clade of theropod dinosaurs which contains four families — the Metriacanthosauridae, Allosauridae, Carcharodontosauridae, and Neovenatoridae. Allosauroids, alongside the family Megalosauroidea, were among t ...

is described from the Upper Jurassic Sergi Formation by Bandeira ''et al.'' (2021), representing the first unambiguous record of a dinosaur from the Jurassic of Brazil reported to date. * A study on the phylogenetic affinities of putative carcharodontosaurid teeth from the Upper Cretaceous strata in northern and central Patagonia, and on their implications for the knowledge of the timing of extinction of carcharodontosaurids in South America, is published by Meso ''et al.'' (2021). * Description of new fossil material of ''

Phuwiangvenator ''Phuwiangvenator'' ("hunter of Phu Wiang") is a genus of 6 meter long megaraptoran theropod that lived during the Early Cretaceous period in what is now Thailand. It contains a single species, ''P. yaemniyomi'', recovered from the Sao Khua For ...

yaemniyomi'' from the Lower Cretaceous

( Thailand), and a study on its implications for the knowledge of the early evolution of Megaraptora, is published by Samathi ''et al.'' (2021). * A study on the skeletal anatomy of '' Aerosteon riocoloradensis'' is published by Aranciaga Rolando ''et al.'' (2021). * Fragmentary specimens of tyrannosaurid theropods from the Dinosaur Park Formation of the Alberta, Canada) in the collection of the San Diego Natural History Museum were described by Yun (2021). * Bones of tyrannosaurid theropods with extensive tooth marks matching the teeth of tyrannosaurids are described from the Upper Cretaceous of the

San Juan Basin The San Juan Basin is a geologic structural basin located near the Four Corners region of the Southwestern United States. The basin covers 7,500 square miles and resides in northwestern New Mexico, southwestern Colorado, and parts of Utah a ...

(northwestern New Mexico, United States) by Dalman &

Lucas Lucas or LUCAS may refer to: People * Lucas (surname) * Lucas (given name) Arts and entertainment * Luca Family Singers, also known as "lucas ligner en torsk" * ''Lucas'' (album) (2007), an album by Skeletons and the Kings of All Cities * ''L ...

(2021), who interpret this finding as evidence for cannibalistic behavior among tyrannosaurids. * Caneer, Moklestad & Lucas (2021) describe structures which are not readily assignable to any known ichnotaxon from the Upper Cretaceous of the Raton Basin (New Mexico), and interpret them as one footprint and two forearm/hand prints probably produced by a large tyrannosaurid theropod standing up from a prone position. * Perinatal tyrannosaurid bones and teeth are described from the Upper Cretaceous Two Medicine Formation ( Montana, United States) and Horseshoe Canyon Formation ( Alberta, Canada) by Funston ''et al.'' (2021), who evaluate the implications of these findings for the knowledge of the minimum hatchling size of tyrannosaurids, their nesting habits and development of their teeth. * A study on tyrannosaurid tracks from the Campanian

Wapiti Formation The Wapiti Formation is a geological formation of the Western Canada Sedimentary Basin in northwestern Alberta, and northeastern British Columbia, Canada. Its deposition spanned the time interval from the lower Campanian through to the upper Maast ...

(Alberta, Canada), evaluating the implications of these tracks for the knowledge of changes in pedal anatomy of tyrannosaurids during their ontogeny, is published by Enriquez ''et al.'' (2021). * Tyrannosaurid fossil material is described from the Blagoveshchensk and Kundur fossil localities (Amur Region, Russia) by Bolotsky, Ermatsans & Bolotsky (2021). * A study on possible causes of monopolization of large carnivore guilds in Asian and American dinosaur assemblages by tyrannosaurids in the latest Cretaceous is published by Holtz (2021). * A study on the morphology, frequency, and ontogeny of facial bite marks in tyrannosaurid specimens is published by Brown, Currie & Therrien (2021), who interpret the ontogenetic distribution of bite scars in the studied specimens as possible evidence of agonistic behaviour associated with the onset of sexual maturity. * A study on changes of mandibular biomechanical properties and tooth morphology in '' Albertosaurus sarcophagus'' and '' Gorgosaurus libratus'' during their ontogeny is published by Therrien ''et al.'' (2021), who interpret their findings as indicating the occurrence of ontogenetic dietary shift in albertosaurine tyrannosaurids. * A study on the mechanical properties of the mandibles of tyrannosaurine tyrannosaurids representing different ontogenetic stages (including small juvenile) is published by Rowe & Snively (2021). * New

bone bed A bone bed is any geological stratum or deposit that contains bones of whatever kind. Inevitably, such deposits are sedimentary in nature. Not a formal term, it tends to be used more to describe especially dense collections such as Lagerstätte. ...

containing at least four specimens of ''

Teratophoneus ''Teratophoneus'' ("monstrous murderer"; Greek: ''teras'', "monster" and ''phoneus'', "murderer") is a genus of tyrannosaurid dinosaur which lived during the late Cretaceous period (late Campanian age, about 77 to 76 million years ago) in what i ...

curriei'' or a related tyrannosaurid is described from the Campanian Kaiparowits Formation ( Utah, United States) by Titus ''et al.'' (2021), who study the taphonomy of this bone bed, and evaluate its implications for the knowledge whether known accumulations of tyrannosaurid specimens represent time-averaged or forced accumulations, or whether they are evidence of gregariousness of tyrannosaurids. * A metatarsal of juvenile tyrannosaurid theropod from the Dinosaur Park Formation of the Alberta, Canada, possibly referable to ''

torosus'' was described by Yun (2021). * A study on the anatomy of the braincases of two specimens of ''Daspletosaurus'' is published by Paulina Carabajal ''et al.'' (2021). * A study aiming to calculate population variables such as abundance at any one time, species persistence and total number of individuals that ever lived for '' Tyrannosaurus rex'' is published by Marshall ''et al.'' (2021); the study is subsequently criticized by Meiri (2022). * A study aiming to estimate the natural frequency of the vertical swaying of the tail and the preferred walking speed and step frequency of '' Tyrannosaurus rex'' is published by van Bijlert, van Soest & Schulp (2021). * A study on the morphology of the neurovascular canal in the dentary of ''Tyrannosaurus rex'' is published by Kawabe & Hattori (2021). * A study attempting to determine bite force of a juvenile ''Tyrannosaurus rex'', based on mechanical tests designed to replicate bite marks attributed to juvenile specimens of this species, is published by Peterson, Tseng & Brink (2021). * A study on the

taphonomic Taphonomy is the study of how organisms decay and become fossilized or preserved in the paleontological record. The term ''taphonomy'' (from Greek , 'burial' and , 'law') was introduced to paleontology in 1940 by Soviet scientist Ivan Efremov t ...

and geochemical history of the ''Tyrannosaurus rex'' specimen MOR 1125 is published by Ullmann ''et al.'' (2021). * A study on the anatomy of the postcranial skeleton and on the phylogenetic relationships of '' Pelecanimimus polyodon'' is published by Cuesta ''et al.'' (2021), who name a new clade Macrocheiriformes, defined as ''Pelecanimimus'' and all derived ornithomimosaurs. * New

ornithomimid Ornithomimidae (meaning "bird-mimics") is a family of theropod dinosaurs which bore a superficial resemblance to modern ostriches. Ornithomimids were fast, omnivorous or herbivorous dinosaurs known mainly from the Late Cretaceous Period of Laura ...

fossil material, providing new information on the distal tarsal morphology in ornithomimids, is described from the Campanian Kaiparowits Formation ( Utah, United States) by Nottrodt & Farke (2021). * A study on pelvic musculature in non-avian maniraptorans is published by Rhodes, Henderson & Currie (2021). * A study on the neuroanatomy of a new

skeleton in the collection of the Henan Geological Museum (China) is published by Agnolín ''et al.'' (2021). *A study on the skeletal anatomy, probable musculature and likely function of tails of

alvarezsauria Alvarezsauroidea is a group of small maniraptoran dinosaurs. Alvarezsauroidea, Alvarezsauridae, and Alvarezsauria are named for the historian Gregorio Álvarez, not the more familiar physicist Luis Alvarez, or his son geologist Walter Alvarez ...

n theropods is published by Meso ''et al.'' (2021). * A study on growth strategies and body miniaturization in the evolutionary history of alvarezsauroid theropods is published by Qin ''et al.'' (2021). * A study on the osteology of '' Fukuivenator paradoxus'' is published by Hattori ''et al.'' (2021), who described previously undescribed elements and reinterpret this genus as a basal therizinosaur. * A study on the anatomy of the postcranial skeleton of ''

Beipiaosaurus ''Beipiaosaurus'' is a genus of therizinosauroid theropod dinosaurs that lived in Asia during the Early Cretaceous in the Yixian Formation. The first remains were found in 1996 and formally described in 1999. Before the discovery of ''Yutyrannus ...

inexpectus'' is published by Liao ''et al.'' (2021). * Reevaluation of putative blood cells preserved in the holotype specimen of ''Beipiaosaurus inexpectus'' is published by Korneisel ''et al.'' (2021), who interpret putative blood cells as more likely to be diagenetic structures. * Reconstructions of the muscular system of the hindlimb, forelimb and the

shoulder girdle The shoulder girdle or pectoral girdle is the set of bones in the appendicular skeleton which connects to the arm on each side. In humans it consists of the clavicle and scapula; in those species with three bones in the shoulder, it consists of t ...

of '' Nothronychus'' are presented by Smith (2021). * Zheng ''et al.'' (2021) study cellular and nuclear preservation in femoral articular cartilage of a specimen of '' Caudipteryx'' from the Yixian Formation (China). * Partial skeleton of '' Elmisaurus rarus'', preserving elements overlapping with known fossil material of '' Nomingia gobiensis'', is described from the Upper Cretaceous Nemegt Formation ( Mongolia) by Funston ''et al.'' (2021), who interpret this specimen as indicating that ''N. gobiensis'' is likely a

of ''E. rarus''. * A study on the body mass of ''

Anzu wyliei ''Anzu'' (named for Anzû, a bird-like daemon in Ancient Mesopotamian religion) is a monospecific genus of caenagnathid dinosaur from North Dakota, South Dakota and Montana that lived during the Late Cretaceous (upper Maastrichtian stage, 67.2- ...

'' is published by Atkins-Weltman, Snively & O'Connor (2021). * A

caenagnathid Caenagnathidae is a family of bird-like maniraptoran theropod dinosaurs from the Cretaceous of North America and Asia. They are a member of the Oviraptorosauria, and close relatives of the Oviraptoridae. Like other oviraptorosaurs, caenagnathids ...

metatarsal is described from the Campanian Mesaverde Formation ( Wyoming, United States; representing the first record of a caenagnathid from this formation) by Yun & Funston (2021), who evaluate the implications of this specimen for the knowledge whether reported differences in metatarsal morphology between ''"Macrophalangia"'' and '' Chirostenotes'' were merely allometric in nature, or whether they might represent phylogenetically informative variation. * An exceptionally preserved, articulated oviraptorid embryo, found inside an elongatoolithid egg in a posture previously unrecognized in a non-avian dinosaur but sharing aspects of bird-like tucking postures, is described from the Upper Cretaceous Hekou Formation (China) by Xing ''et al.'' (2021); however, the conclusions of the authors are subsequently contested by Deeming & Kundrát (2022), who argue that this specimen was not close to hatching, and that the positioning of its head relative to its body cannot bear any relationship to hatching position of this animal. * Cau ''et al.'' (2021) report the identification of additional elements of the pectoral apparatus of the holotype specimen of ''

Halszkaraptor ''Halszkaraptor'' (; meaning " Halszka's seizer") is a genus of waterfowl-like dromaeosaurid dinosaurs from Mongolia that lived during the Late Cretaceous period. It contains only one known species, ''Halszkaraptor escuilliei''. The type speci ...

escuilliei'', including the furcula, and evaluate its implications for the knowledge of the evolution of the avian furcula. * A study on the anatomy of the skeleton of '' Unenlagia comahuensis'' is published by Novas ''et al.'' (2021). * A study on the vertebral pneumaticity in ''Unenlagia comahuensis'' is published by Gianechini & Zurriaguz (2021). * Description of a new troodontid specimen from the Upper Cretaceous

Wulansuhai Formation The Bayan Mandahu Formation (also known as Wulansuhai Formation or Wuliangsuhai Formation) is a geological unit of "redbeds" located near the village of Bayan Mandahu in Inner Mongolia, China Asia (Gobi Desert) and dates from the late Cretaceous P ...

(China), and a study on the phylogenetic relationships and evolutionary history of the Late Cretaceous troodontids, is published by Wang ''et al.'' (2021). *A unique troodontid nest is described by Maipig ''et al.'' (2021), preserving a unique spiral pattern of eggs embedded vertically into substrate. * Multi-individual aggregates of mammal skeletons are described from the Upper Cretaceous Two Medicine Formation ( Montana, United States) by Freimuth ''et al.'' (2021), who interpret these aggregates as the oldest known mammal-bearing regurgitalites, probably produced by '' Troodon formosus''. * A study on the anatomy and phylogenetic relationships of ''

Borogovia ''Borogovia'' is a troodontid theropod dinosaur genus which lived during the Late Cretaceous Period, in what is now Mongolia. In 1971, a Polish-Mongolian expedition discovered the remains of a small theropod at the Altan Ula IV site, in the N ...

gracilicrus'' is published by Cau & Madzia (2021). * Brown, Tanke & Hone (2021) describe a hadrosaurid bone from the Campanian Dinosaur Park Formation ( Alberta, Canada) preserved with bite marks produced by a small- to medium-sized theropod dinosaur, deviating from the majority of known theropod tooth marks and indicative of a behavior similar to mammalian gnawing. * Revision of the biodiversity of theropods from the Dinosaur Park Formation is published by Cullen ''et al.'' (2021). * Exquisitely preserved, ornamented partial eggs with theropod affinities, representing some of the smallest Mesozoic eggs reported to date, are described from the Campanian Kaiparowits Formation ( Utah, United States) by Oser ''et al.'' (2021), who name a new ootaxon '' Stillatuberoolithus storrsi''.

= Sauropodomorphs

= * Review of the diversity and composition of South American sauropodomorph faunas throughout the Late Triassic is published by Pol ''et al.'' (2021). * A study on the evolution of the olfactory system in sauropodomorph dinosaurs, as indicated by the ratio between the size of the olfactory bulbs and cerebral hemispheres in sauropodomorph endocasts, is published by Müller (2021). * A study on the timing of the earliest occurrence of Triassic sauropodomorphs in their northernmost range (

Fleming Fjord Formation The Fleming Fjord Formation, alternatively called the Fleming Fjord Group is an Upper Triassic geological formation in the northeastern coast of Jameson Land, Greenland. It consists of terrestrial sediments and is known for its fossil content. De ...

, Greenland), and on possible relationship between climate changes and early sauropodomorph dispersal to the temperate belt of the Northern Hemisphere, is published by Kent & Clemmensen (2021). * Probable tracks of large sauropodomorphs dinosaurs, potentially representing the largest known tracks belonging to the ichnogenus '' Eosauropus'' reported to date, are described from the Upper Triassic (likely

Rhaetian The Rhaetian is the latest age of the Triassic Period (in geochronology) or the uppermost stage of the Triassic System (in chronostratigraphy). It was preceded by the Norian and succeeded by the Hettangian (the lowermost stage or earliest age ...

)

Blue Anchor Formation The Mercia Mudstone Group is an early Triassic lithostratigraphic group (a sequence of rock strata) which is widespread in Britain, especially in the English Midlands – the name is derived from the ancient kingdom of Mercia which corresponds to t ...

(Penarth, south Wales, United Kingdom) by Falkingham ''et al.'' (2021). * A study on the evolution of the morphological diversity of sauropodomorph dinosaurs is published by Apaldetti ''et al.'' (2021). * New skull material of '' Plateosaurus'', including the first two juvenile skulls of members of this genus, is described from the locality of Frick (

Switzerland ). Swiss law does not designate a ''capital'' as such, but the federal parliament and government are installed in Bern, while other federal institutions, such as the federal courts, are in other cities (Bellinzona, Lausanne, Luzern, Neuchâtel ...

) by Lallensack ''et al.'' (2021), who attempt to determine whether the locality of Frick and German localities of Trossingen and Halberstadt contain specimens of ''Plateosaurus'' belonging to a single species. * A study on the skeletal growth during the ontogeny in '' Massospondylus carinatus'' is published by Chapelle, Botha & Choiniere (2021). * A study on the age of the fossil material of '' Yunnanosaurus youngi'' is published by Ren ''et al.'' (2021). *A study on the cranial anatomy of ''Anchisaurus polyzelus'' and the development of cranial characters in sauropodomorph ontogeny is published by Fabbri ''et al.'' (2021) * An assemblage including over 100 eggs and skeletal specimens of 80 specimens of '' Mussaurus patagonicus'', ranging from embryos to fully-grown adults, is described from the

Laguna Colorada Formation The Laguna Colorada Formation is a geological formation of the Austral Basin in Patagonia, Argentina. The formation belongs to the El Tranquilo Group and dates back to the Early Jurassic, with a maximum age of 192.78 ± 0.14 Ma.Weishampel, Da ...

( Argentina) by Pol ''et al.'' (2021), who assign an Early Jurassic ( Sinemurian) maximum age for the ''Mussaurus'' bearing sediments, and interpret this assemblage as likely evidence of colonial nesting habits, presence of social cohesion throughout the different stages of the lifespan, and age-based social partitioning within a herd structure in ''Mussaurus''. * An extensive Late Jurassic sauropod tracksite, preserving the longest continuous sequence of sauropod

pes Pes (Latin for "foot") or the acronym PES may refer to: Pes * Pes (unit), a Roman unit of length measurement roughly corresponding with a foot * Pes or podatus, a * Pes (rural locality), several rural localities in Russia * Pes (river), a river ...

prints reported to date and representing a rare record of a >180° turn made by the sauropod trackmaker to completely change direction and cross its own trackway, is described from a high altitude locality near Ouray ( Colorado, United States) by Goodell ''et al.'' (2021). * A study on the anatomy of the axial skeleton of ''

Bagualia ''Bagualia'' (meaning "wild horse" in Spanish, after Bagual Canyon, the type locality), is an extinct genus of eusauropod dinosaur, from the Early Jurassic Epoch in what is now Argentina. The type species, ''B. alba'', was formally described in ...

alba'' is published by Gomez, Carballido & Pol (2021). * New fossil material of '' Shunosaurus'', providing new information on the development of the skeleton of this sauropod during its ontogeny, is described from the

Middle Jurassic The Middle Jurassic is the second epoch of the Jurassic Period. It lasted from about 174.1 to 163.5 million years ago. Fossils of land-dwelling animals, such as dinosaurs, from the Middle Jurassic are relatively rare, but geological formations co ...

Shaximiao Formation The Shaximiao Formation () is a Middle Jurassic, Middle to Late Jurassic aged geological formation in Sichuan, China, most notable for the wealth of dinosaurs fossils that have been excavated from its strata. The Shaximiao Formation is exposed in ...

(China) by Ma ''et al.'' (2021). * A study on the skeletal anatomy of the holotype of '' Patagosaurus fariasi'' is published by Holwerda, Rauhut & Pol (2021). * A new specimen of '' Haplocanthosaurus'' with expanded neural canals is described by Wedel ''et al.'' (2021). * A study on the anatomy and phylogenetic relationships of ''

Amphicoelias ''Amphicoelias'' (, meaning "biconcave", from the Greek ἀμφί, ''amphi'': "on both sides", and κοῖλος, ''koilos'': "hollow, concave") is a genus of herbivorous sauropod dinosaur that lived approximately 150 million years ago during t ...

altus'' is published by Mannion, Tschopp & Whitlock (2021). * The paleohistology of two dicraeosaurids from the

La Amarga Formation The La Amarga Formation is a geologic formation with outcrops in the Argentine provinces of Río Negro, Neuquén, and Mendoza. It is the oldest Cretaceous terrestrial formation in the Neuquén Basin. The type locality is La Amarga Arroyo and C ...

( Argentina) is studied by Winholdz and Cerda (2021), who find that the holotype specimen of '' Amargatitanis macni'' belonged to a more mature individual than the holotype of '' Amargasaurus cazaui''. * Fossilized skin of a juvenile member of the genus '' Diplodocus'', providing evidence of new scale shapes and patterns never before seen in

diplodocids Diplodocids, or members of the family Diplodocidae ("double beams"), are a group of sauropod dinosaurs. The family includes some of the longest creatures ever to walk the Earth, including ''Diplodocus'' and '' Supersaurus'', some of which may ha ...

, is described from the Mother's Day Quarry ( Bighorn Basin, Montana, United States) by Gallagher, Poole & Schein (2021). * A study on the anatomy of the braincase of a diplodocid sauropod (possibly '' Leinkupal laticauda'') from the Lower Cretaceous Bajada Colorada Formation (Argentina) is published by Garderes ''et al.'' (2021; final version published in 2022). * Redescription of the anatomy of the braincase of ''

Limaysaurus ''Limaysaurus'' ("Limay lizard") is a genus represented by a single species of rebbachisaurid sauropod dinosaurs, which lived during the mid-Cretaceous period, about 99.6 to 97 million years ago, in the Cenomanian, in what is now South America ( ...

tessonei'' is published by Paulina-Carabajal & Calvo (2021). * A description of well preserved fossil material of ''

Camarasaurus ''Camarasaurus'' ( ) was a genus of quadrupedal, herbivorous dinosaurs and is the most common North American sauropod fossil. Its fossil remains have been found in the Morrison Formation, dating to the Late Jurassic epoch (Kimmeridgian to Titho ...

'', including an articulated, nearly-complete skull, and an analysis of variability within the genus based on cranial allometry trends is published by Woodruff ''et al.'' (2021). * Partial sauropod maxilla, possibly belonging to a brachiosaurid, is described from the Cretaceous ( Albian–

) Longjing Formation (northeast China) by Liao ''et al.'' (2021). * Sauropod tracks probably produced by non-titanosaurian titanosauriforms are described from the Rupelo Formation ( Spain) by Torcida Fernández-Baldor ''et al.'' (2021), who evaluate the paleoenvironmental and paleoecological implications of this finding, and name a new ichnotaxon '' Iniestapodus burgensis''. * A study on tooth replacement rates in early somphospondylans, as indicated by data from a dentary from the Lower Cretaceous (

Aptian The Aptian is an age in the geologic timescale or a stage in the stratigraphic column. It is a subdivision of the Early or Lower Cretaceous Epoch or Series and encompasses the time from 121.4 ± 1.0 Ma to 113.0 ± 1.0 Ma (million years ago), a ...

– Albian) Haoling Formation (China), is published by Chang ''et al.'' (2021). * A study aiming to determine whether titanosaur osteoderms could act as defensive structures is published by Silva Junior ''et al.'' (2021; final version published in 2022). * Description of the anatomy of the referred specimen of ''

Diamantinasaurus ''Diamantinasaurus'' is a genus of titanosaurian sauropod from Australia that lived during the early Late Cretaceous, about 94 million years ago. The type species of the genus is ''D. matildae'', first described and named in 2009 in paleontology, ...

matildae'' and a study on the phylogenetic relationships of this species is published by Poropat ''et al.'' (2021), who name a new clade

Diamantinasauria Diamantinasauria is an extinct clade of non- lithostrotian titanosaurian sauropod dinosaurs, known from the early Late Cretaceous (Cenomanian-Turonian) of South America and Australia. It was named by Poropat and colleagues in 2021, and contains f ...

, which includes it alongside ''

Savannasaurus ''Savannasaurus'' is a genus of titanosaurian sauropod dinosaur from the Late Cretaceous Winton Formation of Queensland, Australia. It contains one species, ''Savannasaurus elliottorum'', named in 2016 by Stephen Poropat and colleagues. The holot ...

'' and '' Sarmientosaurus''. * Fossil material of a giant titanosaur sauropod, distinct from '' Andesaurus'' and probably exceeding '' Patagotitan'' in size, is described from the

Candeleros Formation The Candeleros Formation (formerly known as the Candeleros Member of the "Río Limay Formation") is a geologic formation that crops out in the Río Negro, Neuquén, and Mendoza provinces of northern Patagonia, Argentina. It is the oldest formati ...

( Argentina) by Otero ''et al.'' (2021). * Revision of known fossil material of ''

Pellegrinisaurus ''Pellegrinisaurus'' (meaning ''Lizard from Pelligrini'') is a genus of titanosaurian sauropod dinosaur that lived in South America during the Late Cretaceous period. The holotype was found in the Allen Formation, Argentina. Discovery and namin ...

powelli'' and a study on the skeletal anatomy, bone histology and phylogenetic relationships of this sauropod are published by Cerda ''et al.'' (2021). * New titanosaur remains, possibly belonging to a member of

Colossosauria Colossosauria is a clade of titanosaur sauropods from the latest Early Cretaceous through the Late Cretaceous of South America. The group was originally named by Bernardo González-Riga ''et al.'' in 2019 in paleontology, 2019 and defined as the ...

distinct from previously known taxa, are described from the Upper Cretaceous Portezuelo Formation (Argentina) by Bellardini ''et al.'' (2021). * A study on the anatomy of the axial skeleton of ''

Rinconsaurus ''Rinconsaurus'' is a genus of titanosaur sauropod dinosaur from the Late Cretaceous in what is now Argentina. The type species, ''Rinconsaurus caudamirus'', was described by Calvo and Riga in 2003, and is based on three partial skeletons. Desc ...

caudamirus'' is published by Pérez Moreno ''et al.'' (2021). *A study on the composition of several gastroliths from the Morrison are published by Malone, Strasser, Malone, D'Emic, Brown, and Craddock, who point to the differences between them and the surrounding rock and similarities to another site 1,000 km eastwards to suggest evidence of migration in sauropod dinosaurs. * Description of new fossil material and a study on the phylogenetic relationships of ''

Tengrisaurus ''Tengrisaurus'' (meaning "Tengri lizard") is a genus of lithostrotian sauropod, from the Early Cretaceous (Barremian-Aptian) Murtoi Formation, Russia. It was described in 2017 by Averianov & Skutschas. The type species is ''T. starkovi''. New ...

starkovi'' is published by Averianov, Sizov & Skutschas (2021). * Aureliano ''et al.'' (2021) report preservation of histological structure related to an avian-like air sac system in a vertebra of a

saltasaurid Saltasauridae (named after the Salta region of Argentina where they were first found) is a family of armored herbivorous sauropods from the Upper Cretaceous. They are known from fossils found in South America, Asia, North America, and Europe. Th ...

titanosaur from the Upper Cretaceous São José do Rio Preto Formation (Bauru Group, Brazil). * Evidence of the preservation of nitrogen-bearing organic molecules (identified as proteinaceous moieties) in titanosaur eggshell from the Maastrichtian Lameta Formation ( India) is presented by Dhiman ''et al.'' (2021). * A study on the stable isotope compositions of titanosaurian eggshells, bone and an associated tooth sampled in three Late Cretaceous nesting sites from La Rioja Province (Argentina), evaluating their implications for the knowledge of the body temperature of titanosaur sauropods, their diet, and the environmental conditions they needed reproduce, is published by Leuzinger ''et al.'' (2021).

Ornithischians

* Revision of the phylogenetic nomenclature of ornithischian dinosaurs is published by Madzia ''et al.'' (2021), who name new clades Corythosauria, Euceratopsia, Saphornithischia, Panoplosaurini and Struthiosaurini. * New fossil material of ornithischians, including remains of

euiguanodontia Iguanodontia (the iguanodonts) is a clade of herbivorous dinosaurs that lived from the Middle Jurassic to Late Cretaceous. Some members include ''Camptosaurus'', ''Dryosaurus'', ''Iguanodon'', ''Tenontosaurus'', and the hadrosaurids or "duck-bill ...

n and hadrosaurid ornithopods and the southernmost record of ankylosaurs from South America reported to date, is described from the Upper Cretaceous ( Campanian– Maastrichtian)

Chorrillo Formation The Chorrillo Formation, also named as Chorillo Formation,Río Leona
at Heterodontosaurus tucki'', preserving a suite of novel postcranial features unknown in any other ornithischian dinosaur, and evaluate the implications of this specimen for the knowledge of the evolution of ornithischian respiratory biology.

= Thyreophorans

= * A study on the skeletal anatomy and bone histology of '' Scutellosaurus lawleri'', providing new data on the morphology and new life reconstruction for this dinosaur, is published by Breeden '' et al.'' (2021). * A stegosaurian humerus is described from the

( Argentina) by Rauhut, Carballido & Pol (2021), extending the fossil record of Stegosauria to the Late Jurassic of South America. * A study on the morphology, macro- and microwear, and microanatomy of the stegosaur teeth from the Teete locality (Lower Cretaceous

Batylykh Formation The Batylykh Formation is a geological formation in Yakutia, Russia. It is of an uncertain Early Cretaceous age, probably dating between the Berriasian and the Barremian. It is the oldest unit of the thick Sangar Series within the Vilyuy syne ...

;

Sakha Sakha, officially the Republic of Sakha (Yakutia),, is the largest republic of Russia, located in the Russian Far East, along the Arctic Ocean, with a population of roughly 1 million. Sakha comprises half of the area of its governing Far Eas ...

, Russia), evaluating their implications for the knowledge of the paleobiology of the Teete stegosaur, is published by Skutschas ''et al.'' (2021). * The smallest stegosaur track reported to date, co-occurring with the tracks of larger individuals, is described from the Lower Cretaceous Tugulu Group (Xinjiang, China) by Xing ''et al.'' (2021). * The type locality and holotype of '' Dracopelta zbyszewskii'' are reinterpreted by Russo & Mateus (2021), who also chronicle the history of the holotype. * Riguetti ''et al.'' (2021) describe nodosaurid tracks from the Maastrichtian

El Molino Formation The El Molino Formation is a Maastrichtian geologic formation pertaining to the Puca Group of central Bolivia. The formation comprises fine-grained sandstones and sandy limestones with stromatolites deposited in a shallow marine to lacustrine env ...

(

Bolivia , image_flag = Bandera de Bolivia (Estado).svg , flag_alt = Horizontal tricolor (red, yellow, and green from top to bottom) with the coat of arms of Bolivia in the center , flag_alt2 = 7 × 7 square p ...

), increasing known diversity of ankylosaur tracks from South America. * Several fragmentary skulls and skull elements of ''

Hungarosaurus ''Hungarosaurus tormai'' is a herbivorous nodosaurid ankylosaur from the Upper Cretaceous (Santonian) Csehbánya Formation of the Bakony Mountains of western Hungary. It is the most completely known ankylosaur from the Cretaceous of Europe. Di ...

'', providing new information on the morphological diversity, development and possible function of the ornamentation of nodosaurid skulls, are described by Ősi ''et al.'' (2021). * A study on

dental microwear Dental microwear analysis is a method to infer diet and behavior in extinct animals, especially in fossil specimens. Typically, the patterns of pits and scratches on the occlusal or buccal surface of the enamel are compared with patterns observed ...

and jaw movement of '' Jinyunpelta'', and on its implications for the knowledge of the evolution of the feeding mechanism of

ankylosaurids Ankylosauridae () is a family of armored dinosaurs within Ankylosauria, and is the sister group to Nodosauridae. The oldest known Ankylosaurids date to around 122 million years ago and went extinct 66 million years ago during the Cretaceous–Pal ...

, is published by Kubo ''et al.'' (2021). * Articulated postcranial skeleton of an indeterminate ankylosaurid dinosaur is described from the Barun Goyot Formation ( Mongolia) by Park ''et al.'' (2021), who interpret this specimen as indicating that Asian ankylosaurids evolved rigid bodies with a reduced number of pedal

phalanges The phalanges (singular: ''phalanx'' ) are digital bones in the hands and feet of most vertebrates. In primates, the thumbs and big toes have two phalanges while the other digits have three phalanges. The phalanges are classed as long bones. ...

, as well as the existence of at least two forms of flank armor in ankylosaurids, and discuss possible adaptations for digging in ankylosaurids.

= Cerapods

= * A study on the skeletal anatomy and phylogenetic relationships of ''

Haya griva ''Haya'' is an extinct genus of basal neornithischian dinosaur known from Mongolia. Description ''Haya'' is known from several well-preserved specimens which collected in the Khugenetslavkant locality by the joint Mongolian Academy of Sciences ...

'' is published by Barta & Norell (2021). * Duncan ''et al.'' (2021) describe

ornithopod Ornithopoda () is a clade of ornithischian dinosaurs, called ornithopods (), that started out as small, bipedal running grazers and grew in size and numbers until they became one of the most successful groups of herbivores in the Cretaceous world ...

jaws from the Lower Cretaceous Eumeralla Formation (

), and evaluate the implications of these fossils for the knowledge of the diversity of Early Cretaceous ornithopods from this area. * A study on the anatomy of the manus of '' Tenontosaurus tilletti'' is published by Hunt, Cifelli & Davies (2021). * A study on the accumulated remains of '' Dysalotosaurus lettowvorbecki'' from the Upper Jurassic Tendaguru Formation ( Tanzania) is published by Hübner ''et al.'' (2021), who interpret two large bonebeds as most likely resulting from two independent catastrophic mortality events. * A study on the anatomy of the braincase and probable brain size in ''

Proa valdearinnoensis ''Proa'' is a genus of basal styracosternan iguanodont known from the Early Cretaceous Escucha Formation (lower Albian stage) of Teruel Province, Spain. Discovery and naming It contains a single species, ''Proa valdearinnoensis''. The generic ...

'' is published by Knoll ''et al.'' (2021). * A specimen of '' Gobihadros mongoliensis'' preserving features of cessation of growth, indicating that it reached the terminal size and advanced age, is described from the Upper Cretaceous Bayan Shireh Formation ( Mongolia) by Słowiak ''et al.'' (2021), who diagnose this specimen as affected by

calcium pyrophosphate deposition disease Calcium pyrophosphate dihydrate (CPPD) crystal deposition disease, also known as pseudogout and pyrophosphate arthropathy, is a rheumatologic disease which is thought to be secondary to abnormal accumulation of calcium pyrophosphate dihydrate cry ...

, making it the first known non-avian dinosaur specimen affected with this disease. * Redescription of the anatomy and a study on the phylogenetic relationships of '' Lophorhothon atopus'', based on data from the holotype and from a new specimen, is published by Gates & Lamb (2021). * A study on the anatomy of the postcranial skeleton of '' Tanius sinensis'' is published by Borinder ''et al.'' (2021). * Description of new fossil material of '' Tethyshadros insularis'' from the Villaggio del Pescatore fossil site ( Italy), a study on the age of this site and on the phylogenetic affinities of ''T. insularis'', and a reevaluation of claims about the evolution of insular dwarfism in Late Cretaceous hadrosauroids, is published by Chiarenza ''et al.'' (2021). * Description of new fossil material of hadrosaurids from the Upper Cretaceous Lago Colhué Huapí Formation ( Argentina), and a study on the environment inhabited by these hadrosaurids and on the influence of paleoenvironmental conditions on South American hadrosaurid distribution, is published by Ibiricu ''et al.'' (2021). * Holland ''et al.'' (2021) describe an assemblage of late juvenile hadrosaurid specimens from the Spring Creek Bonebed (Alberta, Canada), representing the first record of

lambeosaurines Lambeosaurinae is a group of crested hadrosaurid dinosaurs. Classification Lambeosaurines have been traditionally split into the tribes or clades Parasaurolophini (''Parasaurolophus'', ''Charonosaurus'', others (?).) and Lambeosaurini (''Coryt ...

from the

and possibly indicating that age segregation was a life history strategy among hadrosaurids. * Revision of the type material and a study on the phylogenetic affinities of ''

Latirhinus ''Latirhinus'' (meaning "broad nose" from the Latin ''latus'' (broad) and Greek ῥίς, ''rhis'' (nose)) is an extinct genus of lambeosaurine hadrosaurid dinosaur from the Late Cretaceous of Mexico. The type species, ''Latirhinus uitstlani'', ...

uitstlani'' is published by Ramírez-Velasco, Espinosa-Arrubarrena & Alvarado-Ortega (2021); a study on the taphonomy of the skeletal elements in the holotype of ''L. uitstlani'' designated by the aforementioned authors, on the skeletal composition of the holotype, on the diagnostic utility of the characters used by Ramírez-Velasco, Espinosa-Arrubarrena & Alvarado-Ortega (2021) for referring other specimens to different hadrosaurid clades, and on the phylogenetic affinities of ''L. uitstlani'' is subsequently published by Serrano-Brañas & Prieto-Márquez (2021). *Redescription of ''

Parasaurolophus ''Parasaurolophus'' (; meaning "near crested lizard" in reference to '' Saurolophus)'' is a genus of herbivorous hadrosaurid ornithopod dinosaur that lived in what is now North America and possibly Asia during the Late Cretaceous Period, abou ...

cyrtocristatus'', based on data from a new skull from the Campanian Fruitland Formation ( New Mexico, United States), is published by Gates,

Evans Evans may refer to: People *Evans (surname) *List of people with surname Evans Places United States *Evans Island, an island of Alaska *Evans, Colorado *Evans, Georgia *Evans County, Georgia *Evans, New York *Evans Mills, New York *Evans City, ...

& Sertich (2021). * A study on the injuries of the holotype specimen of '' Bonapartesaurus rionegrensis'', and on their implications for the knowledge of its paleobiology, is published by Cruzado-Caballero ''et al.'' (2021). * Five new partial skulls of ''

peeblesorum'', providing information on the acquisition of the crest and changes to the surrounding cranial elements during the ontogeny of this dinosaur, are described from the Campanian Two Medicine Formation ( Montana, United States) by McFeeters, Evans & Maddin (2021). * A study aiming to determine the taxonomic validity of the species '' Sphaerotholus buchholtzae'' and ''S. edmontonensis'' is published by Woodruff ''et al.'' (2021). * Vinther, Nicholls & Kelly (2021) describe the first fossil cloacal vent in an exceptionally preserved non-avian dinosaur specimen (a specimen of '' Psittacosaurus'' from the Early Cretaceous Jehol deposits of Liaoning, China). * A study on jaws and teeth of juvenile and adult specimens of '' Psittacosaurus lujiatunensis'', aiming to determine whether this dinosaur underwent a dietary shift during its ontogeny, is published by Landi ''et al.'' (2021). * A study on the ontogenetic changes in the femoral histology of ''Psittacosaurus sibiricus'' is published by Skutschas ''et al.'' (2021). * A study on the whole-skull shape in a large sample of specimens of '' Protoceratops andrewsi'' is published by Knapp, Knell & Hone (2021), who argue that the frill of ''P. andrewsi'' shows several characteristics consistent with a socio-sexual trait. * A study on the anatomy of a specimen of ''Protoceratops andrewsi'' from the Bayan Zag locality ( Djadochta Formation, Mongolia), interpreted as most likely to be a large immature female, and on its implications for explanation of the

polymorphism Polymorphism, polymorphic, polymorph, polymorphous, or polymorphy may refer to: Computing * Polymorphism (computer science), the ability in programming to present the same programming interface for differing underlying forms * Ad hoc polymorphis ...

in the fossil material attributed to ''P. andrewsi'' and for diagnosing ''P. andrewsi'' from vertebrae considering the age and sex of compared specimens, is published by Tereshchenko (2021). * Description of a skull of a subadult specimen of '' Einiosaurus procurvicornis'' from the Two Medicine Formation ( Montana, United States), and a study on the implications of this specimen for the knowledge of the sequence and timing of development of primary cranial ornaments in

eucentrosaura Centrosaurinae (from the Greek, meaning "pointed lizards") is a subfamily of ceratopsid dinosaurs, a group of large quadrupedal ornithischians. Centrosaurine fossil remains are known primarily from the northern region of Laramidia (modern day ...

ceratopsids Ceratopsidae (sometimes spelled Ceratopidae) is a family of ceratopsian dinosaurs including ''Triceratops'', ''Centrosaurus'', and ''Styracosaurus''. All known species were quadrupedal herbivores from the Upper Cretaceous. All but one species are k ...

, is published by Wilson & Scannella (2021). * A study on the dentition of '' Stegoceras validum'' and '' Thescelosaurus neglectus'', and on its implications for the knowledge of the feeding behavior of these ornithischians, is published by Hudgins, Currie & Sullivan (2021). * A study on the biodiversity patterns of Late Cretaceous hadrosaurids and ceratopsids from the western interior of North America, evaluating whether the fossil record provides evidence of faunal provinciality of these dinosaurs, is published by Maidment ''et al.'' (2021).

New taxa

Birds

Research

* The study on the phylogenetic relationships and powered flight potential of early birds and their closest relatives published by Pei ''et al.'' (2020), arguing that the potential for powered flight evolved at least three times (once in birds and twice in

dromaeosaurids Dromaeosauridae () is a family of feathered theropod dinosaurs. They were generally small to medium-sized feathered carnivores that flourished in the Cretaceous Period. The name Dromaeosauridae means 'running lizards', from Greek ('), meaning ...

), is criticized by Serrano &

(2021). * Review of the most relevant events in limb evolution across the dinosaur-bird transition and the origins of bird flight is published by Nebreda, Hernández Fernández & Marugán-Lobón (2021). * A study on the diversification rates of birds throughout their evolutionary history is published by Yu, Zhang & Xu (2021). * A study on the evolution of the brain in birds, based on data from extant and recently extinct birds, ''

Archaeopteryx ''Archaeopteryx'' (; ), sometimes referred to by its German name, "" ( ''Primeval Bird''), is a genus of bird-like dinosaurs. The name derives from the ancient Greek (''archaīos''), meaning "ancient", and (''ptéryx''), meaning "feather" ...

'' and non-avian coelurosaurian theropods, is published by Watanabe ''et al.'' (2021). * A study aiming to infer the diets of the last common ancestor of living birds, based on data from digestive system-related genes, is published by Wu (2021), who interprets his findings as indicative of a diet shift from carnivory to herbivory at the non-avian archosaur-to-bird transition, and evaluates possible implications of this diet shift for the evolution of early birds. * Review of methods used to determine diet in modern and fossil birds, evaluating their utility for determination of diets of Mesozoic birds, is published by Miller & Pittman (2021). * A study on patterns and modes of the evolution of skeletal morphology and limb proportions in Mesozoic birds is published by Wang ''et al.'' (2021). * A study on the variation in tooth crown shape of Mesozoic birds, and its implications for the knowledge of their diets, is published by Zhou ''et al.'' (2021). * A study on the impact of tooth loss on the diversification of Mesozoic birds is published by Brocklehurst & Field (2021), who find no evidence for a link between toothlessness and accelerated cladogenesis, as well as no evidence for models whereby acquisitions of toothlessness among Mesozoic birds were driven by an overarching selective trend. * Review of the variability of bone histology in

members of Avialae is published by Monfroy & Kundrát (2021). * A study on the ecomorphology of extant and fossil birds, aiming to determine whether the ecologies of Mesozoic birds can be inferred on the basis of data from measurements of their forelimbs and hindlimbs, is published by Bell ''et al.'' (2021). * The study published by Kaye, Pittman & Wahl (2020), reporting evidence interpreted by the authors as indicative of the feather moulting in the Thermopolis specimen of ''

'', is criticized by Kiat ''et al.'' (2021). * A study on the cellular preservation in the calcified cartilage of specimens of '' Confuciusornis'' and '' Yanornis'' from the Early Cretaceous Jehol biota (northeast China) is published by Bailleul & Zhou (2021). * A study on the nanostructures of the melanosomes sampled from a specimen of ''

Eoconfuciusornis ''Eoconfuciusornis'' a genus of extinct avialan that lived 131 Ma ago, in the Early Cretaceous of China. The type species of ''Eoconfuciusornis'', ''Eoconfuciusornis zhengi'', was named and described by Zhang Fucheng, Zhou Zhonghe and Michae ...

'' from the Lower Cretaceous Huajiying Formation (China) is published by Pan ''et al.'' (2021), who interpret their findings as evidence of brilliant iridescent plumage color in ''Eoconfuciusornis''. * A study on the histology of the scapulocoracoid in ''Confuciusornis'' is published by Wu ''et al.'' (2021). * New enantiornithine specimen with a well-preserved skull, retaining the

plesiomorphic In phylogenetics, a plesiomorphy ("near form") and symplesiomorphy are synonyms for an ancestral character shared by all members of a clade, which does not distinguish the clade from other clades. Plesiomorphy, symplesiomorphy, apomorphy, and ...

dinosaurian palate and diapsid temporal configurations indicative of an akinetic skull, is described from the Lower Cretaceous Jiufotang Formation (China) by Wang ''et al.'' (2021), who evaluate the implications of this specimen for the knowledge of the evolution of bird skulls. * A study on teeth replacement patterns in members of Enantiornithes, based on data from three specimens from the Cretaceous

( Brazil), is published by Wu ''et al.'' (2021). * A study aiming to infer resting metabolic rates of ''

Concornis ''Concornis'' is a genus of enantiornithean birds which lived during the early Cretaceous period, in the late Barremian age about 125 million years ago. Its remains are known from the Calizas de La Huérgina Formation at Las Hoyas, Cuenca prov ...

'' and ''

Iberomesornis ''Iberomesornis'' ("Spanish intermediate bird") is a monotypic genus of enantiornithine bird of the Cretaceous of Spain. Discovery In 1985 the fossil of ''Iberomesornis'' was discovered by Armando Díaz Romeral in the Early Cretaceous Caliza ...

'' on the basis of data from bone histology is published by Cubo ''et al.'' (2021). * A study on the anatomy of the quadrate bone of '' Longipteryx chaoyangensis'', evaluating its possible functional implications, is published by Stidham & O'Connor (2021), who consider '' Camptodontornis yangi'' and ''

Shengjingornis ''Shengjingornis'' is a genus of enantiornithean bird known from the Early Cretaceous of Jinzhou, western Liaoning, China. Its remains were discovered in Jiufotang Formation deposits, dated to 120 million years ago. ''Shengjingornis'' is conside ...

yangi'' as synonyms of ''Longipteryx''. * Description of a new

bohaiornithid Bohaiornithidae is a group of early predatory enantiornitheans from the early Cretaceous Period of China. All known specimens come from the Jiufotang Formation and Yixian Formation, dating to the early Aptian age, 125–120 million years ago. Boh ...

specimen from the Lower Cretaceous Jiufotang Formation (China), providing new information on the skull anatomy and teeth replacement pattern in bohaiornithids, and a study on the phylogenetic relationships of enantiornithines traditionally included in the family Bohaiornithidae, is published by Liu ''et al.'' (2021; final version published in 2022). * A study on the identity of purported gastroliths reported in a referred specimen of ''

Bohaiornis ''Bohaiornis'' is a genus of enantiornithean birds. Fossils have been found from the Lower Cretaceous Jiufotang Formation of western Liaoning, China. The only known species, ''Bohaiornis guoi'', was named by Dongyu Hu, Li Li, Lianhaim Hou and ...

guoi'' from the Early Cretaceous of China is published by Liu ''et al.'' (2021). * A study on the bone histology and growth of the skeleton of ''

Mirarce ''Mirarce'' (meaning "wonderful winged messenger") is a genus of enantornithe bird from the Late Cretaceous of Utah. It contains a single species, ''M. eatoni''.Science NewsMirarce eatoni: Newly-Discovered Cretaceous Bird Lived Among Dinosaurs, ...

eatoni'' is published by Atterholt ''et al.'' (2021). * An almost complete juvenile specimen of ''

Archaeorhynchus ''Archaeorhynchus'' (meaning "ancient snout") is a genus of beaked avialan stem-birds from the early Cretaceous period. A fossil of its only known species, ''Archaeorhynchus spathula'', was first reported in 2005 by Zhou & Zhang to have been fou ...

'' is described from the

Jiufotang Formation (China) by Foth ''et al.'' (2021), who evaluate the implications of the anatomy of this specimen for the knowledge of the ontogenetic development of Mesozoic birds. * A study on variations in bone growth and on the thermal regime of '' Yanornis martini'' is published by Monfroy ''et al.'' (2021). * Ju ''et al.'' (2021) revise the fossil material of '' Iteravis huchzermeyeri'' and '' Gansus zheni'', and consider these species to be

synonymous A synonym is a word, morpheme, or phrase that means exactly or nearly the same as another word, morpheme, or phrase in a given language. For example, in the English language, the words ''begin'', ''start'', ''commence'', and ''initiate'' are all ...

. * A study on the bone histology of ''Gansus yumenensis'', and on its implications for the knowledge of the evolution of uninterrupted bone deposition in birds, is published by Monfroy ''et al.'' (2021). * A cervical vertebra of a member of

Ornithuromorpha Euornithes (from Greek ' meaning "true birds") is a natural group which includes the most recent common ancestor of all avialans closer to modern birds than to ''Sinornis''. Description Clarke ''et al''. (2006) found that the most primitive know ...

distinct from ''

Gargantuavis ''Gargantuavis'' is an extinct genus of large, primitive bird containing the single species ''Gargantuavis philoinos''. It is the only member of the monotypic family Gargantuaviidae. Its fossils were discovered in several formations dating to 73 ...

'', representing the first fossil evidence of a giant bird from the late Maastrichtian of Europe reported to date, is described from Beranuy (Huesca, Spain) by Pérez-Pueyo ''et al.'' (2021). * Torres, Norell &

(2021) describe a new specimen of '' Ichthyornis dispar'' from the Niobrara Formation ( Kansas, United States), preserving a nearly complete skull, and evaluate the implications of the anatomy of this specimen for the knowledge of the evolution of birds and for the knowledge of probable reasons why birds survived the end-Cretaceous mass extinction. * New information on the anatomy of '' Vegavis iaai'', based on data from the holotype specimen which was fully extracted from the sedimentary matrix, is presented by Acosta Hospitaleche &

Worthy Worthy can refer to: People * Worthy (surname) * Worthington Worthy Patterson (born 1931), American basketball player * F. F. Worthington, nicknamed "Worthy" Places * Worthy, see List of generic forms in place names in Ireland and the United Ki ...

(2021). * Mayr & Zelenkov (2021) interpret eogruids and ergilornithids as representatives of the stem group of Struthioniformes, based on data from new fossils from the late Eocene of Mongolia. * A fossil ostrich specimen with exceptional soft-tissue preservation is described from the Miocene Liushu Formation (Linxia Basin, China) by Li ''et al.'' (2021). * A femur of a giant ostrich, significantly larger than the living common ostrich, is described from the Pleistocene

Nihewan Formation Xiaochangliang () is the site of some of the earliest paleolithic remains in East Asia, located in the Nihewan (泥河灣) Basin in Yangyuan County, Hebei, China, most famous for the stone tools discovered there. Stone tools The tool forms disco ...

(

) by Buffetaut & Angst (2021), who assign it to '' Pachystruthio'' indet. and interpret this finding as evidence of wide geographical distribution of giant ostriches in the Early Pleistocene of Eurasia. * A study on the phylogenetic relationships and evolutionary history of extant and fossil tinamous is published by Almeida ''et al.'' (2021). * A mid- Holocene coprolite deposit attributed to the bush moa is reported from southern New Zealand by Wood ''et al.'' (2021), who evaluate the implications of this finding for the knowledge of the diet and ecology of this moa. * A study comparing egg size and volume in extinct island emus and in mainland emu, aiming to determine egg size in relation to body size in island emus and their breeding strategy, is published by

Hume Hume most commonly refers to: * David Hume (1711–1776), Scottish philosopher Hume may also refer to: People * Hume (surname) * Hume (given name) * James Hume Nisbet (1849–1923), Scottish-born novelist and artist In fiction * Hume, the ...

& Robertson (2021). * A study on the phylogenetic relationships of '' Brontornis burmeisteri'' is published by Agnolin (2021), who interprets this taxon as a member of Galloanserae. * Reexamination of specimens of '' Omorhamphus storchii'' and '' Gastornis parisiensis'' alleged to preserve

alveoli Alveolus (; pl. alveoli, adj. alveolar) is a general anatomical term for a concave cavity or pit. Uses in anatomy and zoology * Pulmonary alveolus, an air sac in the lungs ** Alveolar cell or pneumocyte ** Alveolar duct ** Alveolar macrophage * ...

for teeth is published by Louchart ''et al.'' (2021), who reject claims of presence of teeth in gastornithids. * A study on the morphology of the dromornithid brain, based on data from dromornithid endocast material spanning from the late

Oligocene The Oligocene ( ) is a geologic epoch of the Paleogene Period and extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that define the epoch are well identified but the ...

to the late Miocene, is published by Handley & Worthy (2021). * A study on the bone histology, growth dynamics and life history of '' Genyornis newtoni'' is published by Chinsamy & Worthy (2021). * A study on bone pathologies in specimens of ''Genyornis newtoni'' from the

Lake Callabonna Lake Callabonna is a dry salt lake with little to no vegetation located in the Far North (South Australia), Far North region of South Australia. The lake is situated approximately southwest of Cameron Corner Survey Marker, Cameron Corner, the ...

fossil deposit (

) is published by McInerney ''et al.'' (2021), who interpret the studied specimens as likely affected by osteomyelitis. * Partial humerus of a coscoroba swan is described from the Upper Pleistocene Capellanía Formation (Argentina) by Vezzosi ''et al.'' (2021), who evaluate the implications of this finding for the knowledge of the knowledge of the dispersal of Neotropical swans during the Pleistocene. * Partial skull of a pheasant-sized galliform land bird of uncertain phylogenetic placement is described from the latest Eocene or earliest Oligocene Jansen Creek Member of the

Makah Formation The Makah Formation is a geologic formation in Washington (state). It preserves fossils dating back to the Paleogene period. See also * List of fossiliferous stratigraphic units in Washington (state) This article contains a list of fossil-be ...

( Washington, United States) by Mayr, Goedert & Rabenstein (2021), who report that this specimen preserves a foramen in the temporal region that enabled the vena profunda to enter the braincase, and interpret this foramen as a previously unnoticed cranial autapomorphy of galliforms. * Redescription of '' Columba congi'' is published by Shen, Stidham & Li (2021). * Description of new fossil material of '' Scandiavis mikkelseni'' from the Eocene Fur Formation ( Denmark), providing new information on the brain anatomy of this bird, and a study on the phylogenetic affinities of ''Scandiavis'' is published by Heingård ''et al.'' (2021). * Oswald ''et al.'' (2021) recover a nearly complete mitochondrial genome of the

Haitian cave rail Haitian may refer to: Relating to Haiti * ''Haitian'', an adjective referring to something of, from, or related to Haiti ** Haitian Creole, a French-Creole based ** Haitian French, variant of the French language ** Haitians, an ethnic group * Hait ...

(''

Nesotrochis ''Nesotrochis'' is a genus of extinct flightless birds, formerly native to the islands of the Greater Antilles in the Caribbean. Its species are considered examples of insular gigantism. It contains 3 species known from subfossil remains of La ...

steganinos)'' from fossils, and find this bird to be a relative of the families Sarothruridae and Aptornithidae rather than a rallid as previously thought. * A study reconstructing the wing musculature of the

great auk The great auk (''Pinguinus impennis'') is a species of flightless alcid that became extinct in the mid-19th century. It was the only modern species in the genus ''Pinguinus''. It is not closely related to the birds now known as penguins, wh ...

and ''

Mancalla Mancallinae is an extinct subfamily of prehistoric flightless alcids that lived on the Pacific coast of today's California and Mexico from the late Miocene epoch to the early Pleistocene (ranging from at least 7.4 million to 470,000 years ago). ...

'' is published by Watanabe, Field & Matsuoka (2021). * New fossil material of plotopterids, resembling bones of '' Olympidytes'' (which was previously considered endemic to North America), is described from the Eocene to Oligocene Itanoura and Kakinoura formations (

Japan Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north ...

) by Mori & Miyata (2021), who interpret these fossils as indicating that early diversity of this family in Japan was higher than previously thought. * New fossil material of plotopterids is described from Washington by Mayr & Goedert (2021), who also revise the species ''Tonsala buchanani'' and transfer it to the genus '' Klallamornis''. * A carpometacarpus of a petrel, potentially representing a new genus and species, is described from the Miocene

Gaiman Formation The Gaiman Formation ( es, Formación Gaiman), in older literature also referred to as Patagonian Marine Formation ( es, Formación Patagonia Marino, ''Patagoniense''), is a fossiliferous geologic formation of the Peninsula Valdés Basin in the e ...

(Argentina) by Piro & Acosta Hospitaleche (2021). * A study on the anatomy and pneumaticity of the skull and on the

paleoneurology Paleoneurobiology is the study of brain evolution by analysis of brain endocasts to determine endocranial traits and volumes. Considered a subdivision of neuroscience, paleoneurobiology combines techniques from other fields of study including pa ...

of the fossil banded penguin ''Spheniscus urbinai'' is published by Acosta Hospitaleche, Paulina‐Carabajal & Yury‐Yáñez (2021). * A study on the new referred material of ''

Dryornis ''Dryornis'' (meaning "tree bird"), also called the Argentinian vulture, is an extinct genus of cathartid (New World vulture), known from Argentina. The genus contains two species, ''D. pampeanus'' and ''D. hatcheri''. Discovery and naming ' ...

pampeanus'' from the Pliocene Chapadmalal Formation (Argentina) and on the phylogenetic relationships of this species is published by Degrange ''et al.'' (2021), who interpret ''D. pampeanus'' as the largest cathartiform reported to date. * The first unequivocal fossil material of

teratorns Teratornithidae is an extinct family (biology), family of very large Bird of prey, birds of prey that lived in North and South America from the Oligocene, Late Oligocene to the Pleistocene, Late Pleistocene. They include some of the largest known ...

from the Pleistocene of South America is described from four fossiliferous localities of Central Argentina by Cenizo ''et al.'' (2021), who evaluate the implications of these fossils for the knowledge of the evolutionary history of teratorns, and update the taxonomy of the family. * A study on the feeding capabilities and behaviour of the Haast's eagle is published by van Heteren ''et al.'' (2021). * Description of a partial skeleton of a member of the genus '' Septencoracias'' from the Eocene London Clay ( United Kingdom), belonging or related to the species ''S. morsensis'', and a study on the phylogenetic affinities and likely ecology of this bird is published by Mayr (2021). * Redescription of the type specimen of '' Macrornis tanaupus'' from the Eocene Totland Bay Formation ( Hampshire, United Kingdom) is published by Buffetaut & Angst (2021), who interpret this fossil as a partial tibiotarsus of a large terrestrial bird, possibly a phorusrhacid. * A review of the knowledge of phorusrhacid skull anatomy is presented by Degrange (2021). * Mayr, De Pietri & Scofield (2021) describe new fossil material of birds from the Eocene

Nanjemoy Formation The Nanjemoy Formation is a geologic formation pertaining to both the Wilcox Group and the Pamunkey Group of the eastern United States, stretching across the states of Virginia, Maryland, and District of Columbia. The formation crops out east of ...

( Virginia, United States), including the first representatives of the families

Messelasturidae Messelasturidae is an extinct family of birds known from the Eocene of North America and Europe. Their morphology is a mosiac that in some aspects are strongly convergent with modern hawks and falcons, but in others are more similar to parrots. ...

, Psittacopedidae and

Zygodactylidae Zygodactylidae is a family of extinct birds found in Europe and North America from the Eocene epoch to the Middle Miocene. First named in 1971, based on fragmentary remains of two species from Germany, a more complete description of the birds bec ...

from this formation. * Two passerine specimens representing different size classes (thrush-sized and sylvid-sized), providing information on skeletal element proportions of the middle Miocene passerines, are described from the Miocene of Austria by Happ ''et al.'' (2021). * A distal end of the left tarsometatarsus of a

phasianid The Phasianidae are a family of heavy, ground-living birds, which includes pheasants, partridges, junglefowl, chickens, turkeys, Old World quail, and peafowl. The family includes many of the most popular gamebirds. The family is a large one and i ...

, which represents the first avian fossil record of Taiwan, is described from the Pleistocene Chiting Formation ( Tainan, Taiwan) by Tsai & Mayr (2021). * A study on the mechanics of egg incubation by giant extinct birds is published by Yen et al. (2021). * Revision of the fossil material of birds from Miocene localities in the Iberian Peninsula is published by Sánchez-Marco (2021). * Ramírez-Castro & Reynoso (2021) report fossil material of a shelduck and a

ringed kingfisher The ringed kingfisher (''Megaceryle torquata'') is a large, conspicuous and noisy kingfisher bird commonly found along the lower Rio Grande valley in southeasternmost Texas in the United States through Central America to Tierra del Fuego in Sout ...

from the Chapala-Zacoalco basins ( Mexico), providing new information on the distribution of these birds in the Late Pleistocene. * An assemblage of bird bones dated to late Pleistocene through middle Holocene is described from the Istykskaya cave (

Pamir Mountains The Pamir Mountains are a mountain range between Central Asia and Pakistan. It is located at a junction with other notable mountains, namely the Tian Shan, Karakoram, Kunlun, Hindu Kush and the Himalaya mountain ranges. They are among the world ...

; Tajikistan) by Zelenkov, Sayfulloev, Shnaider (2021), who report the presence of bones of the water rail and a species of ''

Podiceps ''Podiceps'' is a genus of birds in the grebe family. The genus name comes from Latin ''podicis'', "rear-end" and ''ped'', "foot", and is a reference to the placement of a grebe's legs towards the rear of its body. It has representatives breed ...

'' (the black-necked grebe or the horned grebe) which were not recorded at such high altitudes before, and interpret this finding as evidence of milder environmental conditions in Eastern Pamir during late Quaternary. * A study on the sensory systems in extant kiwis and the kākāpō and extinct moa and elephant birds is published by Johnston & Mitchell (2021). * A study aiming to determine the impact of global climatic changes during the last 120,000 years on Afro-Palearctic migrant birds, as indicated by paleoclimate data and genomic-based estimates of effective population size, is published by Thorup ''et al.'' (2021).

New taxa

Pterosaurs

Research

* A study aiming to determine the nature and average number of osteological characters used to diagnose pterosaur species, as well as aiming to estimate how many pterosaur taxa are still unknown, is published by Fernandes, Nunes & Costa (2021). * A study on the phylogenetic affinities of pterosaurs is published by Baron (2021). * A study on the flight abilities of hatchling pterosaurs is published by Naish, Witton & Martin-Silverstone (2021). * A study on size range of pterosaurs from the Cretaceous Kem Kem Group (Morocco) and on the bone histology of small pterosaur specimens from these strata is published by Smith ''et al.'' (2021), who interpret their findings as indicating that in the Cretaceous period the niches previously occupied by small pterosaurs were increasingly occupied by early ontogenetic stages of large pterosaurs rather than by birds. * New information on the skeletal anatomy of '' Austriadraco dallavecchiai'' is provided by Dalla Vecchia (2021). * Fossil material of a

rhamphorhynchine Rhamphorhynchidae is a group of early pterosaurs named after '' Rhamphorhynchus'', that lived in the Late Jurassic. The family Rhamphorhynchidae was named in 1870 by Harry Govier Seeley.Seeley, H.G. (1870). "The Orithosauria: An Elementary Stud ...

pterosaur is described from the Upper Jurassic Cerro Campamento Formation ( Chile) by Alarcón-Muñoz ''et al.'' (2021), representing the first record of this group from

Gondwana Gondwana () was a large landmass, often referred to as a supercontinent, that formed during the late Neoproterozoic (about 550 million years ago) and began to break up during the Jurassic period (about 180 million years ago). The final stages ...

reported to date. * An early juvenile or late hatchling specimen of '' Kunpengopterus sinensis'', providing new information on the skeletal changes during ontogeny in wukongopterids, is described from the Tiaojishan Formation (

) by Jiang ''et al.'' (2021). * Pêgas, Costa &

(2021) attempt to reconstruct the adductor musculature of the pterodactyloid skull, and to estimate bite force for nine pterodactyloid species. * A study on soft tissues of a pterodactyloid specimen from the Upper Jurassic Solnhofen Limestones ( Germany) is published by Pittman ''et al.'' (2021), who interpret their findings as providing evidence of the presence of a biological wing root fairing in pterosaurs. * A well-preserved large skull of '' Ctenochasma elegans'' is described from the Upper Jurassic Painten Formation ( Germany) by Bennett (2021). * Partial mandible of '' Forfexopterus'' is described from the Early Cretaceous Jehol Biota (China) by Zhou, Wang & Wang (2021), who report evidence of tooth wear in this specimen, making it the first known record of tooth-tooth occlusion in ctenochasmatids, and evaluate its implications for the knowledge of the feeding strategy of ctenochasmatids. * Fragment of an ulna of a

pteranodontid The Pteranodontidae are a Family (biology), family of large pterosaurs of the Cretaceous Period of North America and Africa. The family was named in 1876 by Othniel Charles Marsh. Pteranodontids had a distinctive, elongated crest jutting from the ...

pterosaur is described from the Campanian locality Polunino 2 (

Volgograd Oblast Volgograd Oblast (russian: Волгогра́дская о́бласть, ''Volgogradskaya oblast'') is a federal subjects of Russia, federal subject (an oblast) of Russia, located in the Volga region, Volga region of Southern Russia. Its adminis ...

, Russia) by Averianov & Yarkov (2021), representing the first record of the family Pteranodontidae from the Lower Volga region reported so far. * A review of putative

boreopterid Boreopteridae (meaning "northern wings") is a group of pterodactyloid pterosaurs from the Aptian-age Lower Cretaceous Yixian Formation of Liaoning, China. Classification In 2006, Lü Junchang and colleagues named the clade Boreopteridae for the ...

pterosaurs from the South Korea was published by Yun (2021), who concluded that they could not be confidently referred to Boreopteridae. * New specimen of ''

Istiodactylus ''Istiodactylus'' is a genus of pterosaur that lived during the Early Cretaceous period, about 120 million years ago. The first fossil was discovered on the English Isle of Wight in 1887, and in 1901 became the holotype specimen of a new species ...

latidens'', probably coming from the Lower Cretaceous Vectis Formation ( United Kingdom) and possibly representing the missing jaws of the holotype of this species, is described by Averianov ''et al.'' (2021). * Bantim ''et al.'' (2021) describe a

pteranodontoid Pteranodontoidea (or pteranodontoids, from Greek meaning "toothless wings") is an extinct clade of ornithocheiroid pterosaurs from the Early to Late Cretaceous (early Valanginian to late Maastrichtian stages) of Asia, Africa, Europe, North Americ ...

pterosaur with anhanguerid affinities from

-age deposits of the Romualdo Formation ( Brazil). * A new pterodactyloid mandible from the Valanginian of Germany is described by Abel ''et al.'' (2021), representing the oldest anhanguerian known to date. * A study on the variation of pneumaticity patterns in the vertebral column of an anhanguerid specimen from the Romualdo Formation is published by Buchmann ''et al.'' (2021). * Solonin ''et al.'' (2021) describe teeth from the Upper Cretaceous (

) Dmitrov Formation ( Ryazan Oblast, Russia), referrable to

ornithocheirid Ornithocheiridae (or ornithocheirids, meaning "bird hands") is a group of pterosaurs within the suborder Pterodactyloidea. These pterosaurs were among the last to possess teeth. Members that belong to this group lived from the Early to Late Cr ...

pterosaurs, leading to the first occurrence of them in said formation. * A well-preserved, almost complete and articulated new specimen of '' Tupandactylus navigans'', associated with soft tissue remains, is described from the Lower Cretaceous Crato Formation ( Brazil) by Beccari ''et al.'' (2021). * New specimen of ''

Sinopterus ''Sinopterus'' (meaning "Chinese wing") was a genus of tapejarid pterodactyloid pterosaur from the Aptian-age Lower Cretaceous Jiufotang Formation of Chaoyang, Liaoning, China. It was first described and named by Wang Xiaolin and Zhou Zhonghe. ...

dongi'', improving knowledge on the anatomy of this pterosaur, is described from the Lower Cretaceous Jiufotang Formation (China) by Shen ''et al.'' (2021). * Partial femur of a large-sized

dsungaripteroid Dsungaripteroidea is a group of pterosaurs within the suborder Pterodactyloidea. Evolutionary history The earliest known fossils attributed to this group are from the Kimmeridgian-age Upper Jurassic Argiles d'Octeville Formation of France, dat ...

pterosaur is described from the Upper Jurassic ( Kimmeridgian) Praia da Amoreira–Porto Novo Formation ( Portugal) by Bertozzo ''et al.'' (2021), representing the second confirmed report of a dsungaripteroid from the Jurassic, and the first record of this group from the Iberian Peninsula reported to date. * Postcranial elements referrable to '' Lonchognathosaurus'', confirming the validity of the genus and providing new information on the anatomy of this pterosaur, are described from the Lower Cretaceous

Lianmuqin Formation The Lianmuqin Formation, also transcribed as Lianmugin Formation,

(China) by Augustin ''et al.'' (2021). * 114 small pterosaur footprints, possibly produced by pterosaurs belonging to the species '' Noripterus complicidens'', are described from the Lower Cretaceous Shengjinkou Formation (China) by Li, Wang & Jiang (2021), who name a new ichnospecies '' Pteraichnus wuerhoensis''. * New fossil material of pterosaurs is described from the Lower Cretaceous Lianmuqin Formation (China) by Augustin ''et al.'' (2021), who interpret these fossils as probable evidence of the presence of a second dsungaripterid taxon (distinct from ''Lonchognathosaurus'') in this formation. * New fossil material of dsungaripterids is described from the Lower Cretaceous Hutubei Formation (China) by Augustin ''et al.'' (2021), representing the first record of pterosaurs from this formation reported to date, and one of the oldest records of dsungaripterids from the Tugulu Group. * A study on the internal architecture and mechanical properties of a hyper-elongate cervical vertebra of an azhdarchid pterosaur from the Kem Kem Group ( Morocco) is published by Williams ''et al.'' (2021). * Fragment of the wing metacarpal of an azhdarchid is described from the Campanian of the

Orenburg Oblast Orenburg Oblast (russian: Оренбургская область, ''Orenburgskaya oblast'') is a federal subject of Russia (an oblast). Its administrative center is the city of Orenburg. From 1938 to 1957, it bore the name ''Chkalov Oblast'' () ...

( Russia) by Averianov, Zverkov & Nikiforov (2021), representing the first record of a pterosaur from the Late Cretaceous of Southern Urals reported to date. * A study on the anatomy and phylogenetic affinities of '' Aerotitan sudamericanus'' is published by Pêgas ''et al.'' (2021; final version published in 2022), who name the new clades Azhdarchomorpha and

Alanqidae Azhdarchoidea (or azhdarchoids) is a group of pterosaurs within the suborder Pterodactyloidea, more specifically within the group Ornithocheiroidea. Pterosaurs belonging to this group lived throughout the Early and Late Cretaceous periods, with ...

. * A large wing bone (possibly an ulna) of a pterosaur with an estimated wingspan comparable with the holotype specimen of '' Cryodrakon boreas'' is described from the Campanian Kaiparowits Formation ( Utah, United States) by Farke (2021). *Studies on the paleoenvironment, functional morphology, and the phylogenetic affinities of ''

Quetzalcoatlus ''Quetzalcoatlus'' is a genus of pterosaur known from the Late Cretaceous period of North America (Maastrichtian stage); its members were among the largest known flying animals of all time. ''Quetzalcoatlus'' is a member of the Azhdarchidae, ...

,'' which also focuses on the phylogeny of pterosaurs in general and names the new clades

Azhdarchiformes Azhdarchoidea (or azhdarchoids) is a group of pterosaurs within the suborder Pterodactyloidea, more specifically within the group Ornithocheiroidea. Pterosaurs belonging to this group lived throughout the Early and Late Cretaceous periods, with ...

, Nyctosauromorpha and Ornithocheiriformes are published by Lehman ''et al.'' (2021), Padian ''et al.'' (2021) and Andres (2021).

New taxa

Other archosaurs

Research

* Marchetti ''et al.'' (2021) revise the tetrapod (including

dinosauromorph Dinosauromorpha is a clade of avemetatarsalian archosaurs (reptiles closer to birds than to crocodilians) that includes the Dinosauria (dinosaurs) and some of their close relatives. It was originally defined to include dinosauriforms and lag ...

) footprint assemblage from the Quarziti del Monte Serra Formation ( Ladinian of Italy), and interpret this assemblage and other findings of Ladinian dinosauromorph footprints as evidence of wide dispersal of dinosauromorphs as early as the Middle Triassic. * The first putative forelimb and pectoral girdle of '' Lagerpeton chanarensis'' is described by McCabe & Nesbitt (2021). * A study on the nature of tooth attachment in

silesaurids Silesauridae is an extinct family of Triassic dinosauriforms. It is most commonly considered to be a clade of non-dinosaur dinosauriforms, and the sister group of dinosaurs. Some studies have instead suggested that most or all silesaurids compri ...

, and on its implications of the knowledge of the evolution of tooth attachment of archosaurs, is published by Mestriner ''et al.'' (2021). * Two partial skeletons of ''

Lewisuchus ''Lewisuchus'' is a genus of archosaur that lived during the Late Triassic (early Carnian). As a silesaurid dinosauriform, it was a member of the group of reptiles most commonly considered to be the closest relatives of dinosaurs (possibly tr ...

admixtus'', providing new information on the anatomy of this

dinosauriform Dinosauromorpha is a clade of avemetatarsalian archosaurs (reptiles closer to birds than to crocodilians) that includes the Dinosauria (dinosaurs) and some of their close relatives. It was originally defined to include dinosauriforms and lager ...

, are described from the Chañares Formation (Argentina) by Agnolín ''et al.'' (2021).

References

{{reflist Archosaurs 2021 in paleontology