''Erliansaurus'' (meaning "Erlian lizard") is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

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

theropod Theropoda (; ), whose members are known as theropods, is a dinosaur clade that is characterized by hollow bones and three toes and claws on each limb. Theropods are generally classed as a group of saurischian dinosaurs. They were ancestrally c ...

dinosaur Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the evolution of dinosaurs is t ...

that lived in

Asia Asia (, ) is one of the world's most notable geographical regions, which is either considered a continent in its own right or a subcontinent of Eurasia, which shares the continental landmass of Afro-Eurasia with Africa. Asia covers an area ...

during 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 ...

stage of the

Late Cretaceous The Late Cretaceous (100.5–66 Ma) is the younger of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''creta'', the ...

period in what is now Nei Mongol, Iren Dabasu Formation.

Discovery and naming

The remains of ''Erliansaurus'' were found near Sanhangobi in

Inner Mongolia Inner Mongolia, officially the Inner Mongolia Autonomous Region, is an autonomous region of the People's Republic of China. Its border includes most of the length of China's border with the country of Mongolia. Inner Mongolia also accounts for a ...

in 1999. The

type species In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specimen ...

, ''Erliansaurus bellamanus'', was described by Xu Xing, Zhang Xiaohong,

Paul Sereno Paul Callistus Sereno (born October 11, 1957) is a professor of paleontology at the University of Chicago and a National Geographic "explorer-in-residence" who has discovered several new dinosaur species on several continents, including at sites ...

Zhao Xijin Zhao Xijin (赵喜进; born c. 1935 died July 21, 2012) was a Chinese paleontologist notable for having named numerous dinosaurs. He was a professor at Beijing's Institute of Vertebrate Paleontology and Paleoanthropology. Biography Zhao Xijin was ...

, Kuang Xuewen, Han Jun and

Tan Lin Tan Anthony Lin is an American poet, author, filmmaker, and professor. He defines his work as “ambient" literature, which draws on and samples source material from the Internet and popular culture to address issues involving plagiarism, copyrig ...

in 2002. The generic name refers to the town of Erlian and the

specific name Specific name may refer to: * in Database management systems, a system-assigned name that is unique within a particular database In taxonomy, either of these two meanings, each with its own set of rules: * Specific name (botany), the two-part (bino ...

is derived from

Latin Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...

''bellus'', "beautiful", and ''manus'', "hand", in reference to the exquisite preservation of the forelimb. The

holotype A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of several ...

, LH V0002, was uncovered in the

Iren Dabasu Formation The Iren Dabasu Formation (also known as Erlian Formation) is a Late Cretaceous geologic formation in the Iren Nor region of Inner Mongolia. Dinosaur remains diagnostic to the genus level are among the fossils that have been recovered from the fo ...

dating from the Cenomanian stage. It consists of a partial skeleton belonging to a subadult individual. It includes two cervical, one dorsal and two caudal vertebrae; a right scapula; a left forelimb only lacking the

carpus In human anatomy, the wrist is variously defined as (1) the carpus or carpal bones, the complex of eight bones forming the proximal skeletal segment of the hand; "The wrist contains eight bones, roughly aligned in two rows, known as the carpal ...

; a partial right ilium and a fragmented ischium and pubis; the right

femur The femur (; ), or thigh bone, is the proximal bone of the hindlimb in tetrapod vertebrates. The head of the femur articulates with the acetabulum in the pelvic bone forming the hip joint, while the distal part of the femur articulates with ...

; both

tibia The tibia (; ), also known as the shinbone or shankbone, is the larger, stronger, and anterior (frontal) of the two bones in the leg below the knee in vertebrates (the other being the fibula, behind and to the outside of the tibia); it connects ...

e, a right

fibula The fibula or calf bone is a leg bone on the lateral side of the tibia, to which it is connected above and below. It is the smaller of the two bones and, in proportion to its length, the most slender of all the long bones. Its upper extremity is ...

and partial

metatarsals The metatarsal bones, or metatarsus, are a group of five long bones in the foot, located between the tarsal bones of the hind- and mid-foot and the phalanges of the toes. Lacking individual names, the metatarsal bones are numbered from the medi ...

. No skull traces were found.

Description

The holotype specimen represents a not fully-grown individual based on one unfused caudal vertebra, and therefore its adult size may be larger than the contemporary ''

Neimongosaurus ''Neimongosaurus'' (meaning "Nei Mongol lizard") is a genus of herbivorous therizinosaur theropod dinosaur that lived in Asia during the Cenomanian stage of the Late Cretaceous period in what is now the Iren Dabasu Formation. Discovery and namin ...

''. It was a small to medium-sized therizinosaur with an estimated length from and a weight of .Genus List for Holtz 2012
/ref> ''Erliansaurus'' was a bipedal herbivore. For a therizinosauroid, its cervicals were rather short. The preserved femur was very straight and had a very rounded

femoral head The femoral head (femur head or head of the femur) is the highest part of the thigh bone (femur). It is supported by the femoral neck. Structure The head is globular and forms rather more than a hemisphere, is directed upward, medialward, and a l ...

; it measures . The tibia was relatively elongated, measuring long. Its

had an uncommon form, with a very high front edge and a concave top. The left arm is exceptionally preserved with almost every element intact, its hands bore enormous, strongly recurved and pointed claws of which the thumb claw was the largest, however, the carpal bones are missing.

Classification

''Erliansaurus'' was by the describers assigned to the

Therizinosauroidea 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 ...

, in a basal position and likely not a therizinosaurid. The cladistic analysis performed by the revision of Zanno in 2010 recovered it as a therizinosauroid. Some early

cladistic Cladistics (; ) is an approach to biological classification in which organisms are categorized in groups (" clades") based on hypotheses of most recent common ancestry. The evidence for hypothesized relationships is typically shared derived char ...

analyses however, have recovered it as a basal member of the

Therizinosauridae Therizinosauridae (meaning 'scythe lizards')Translated paper
is a family of derived (advanc ...

. The cladogram below is the result of the recently performed

phylogenetic analysis In biology, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups o ...

of the Therizinosauridae by Hartman et al.

2019 File:2019 collage v1.png, From top left, clockwise: Hong Kong protests turn to widespread riots and civil disobedience; House of Representatives votes to adopt articles of impeachment against Donald Trump; CRISPR gene editing first used to experim ...

References

{{Taxonbar, from=Q1525258 Late Cretaceous dinosaurs of Asia Fossil taxa described in 2002 Therizinosaurs Taxa named by Xu Xing Taxa named by Paul Sereno

Discovery and naming

Description

Classification

See also

References