''Lalieudorhynchus'' is an

extinct Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...

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 ...

caseid Caseidae are an Extinction, extinct Family (biology), family of Basal (phylogenetics), basal synapsids that lived from the Late Carboniferous to Middle Permian between about 300 and 265 million years ago. Fossils of these animals come from the so ...

synapsid Synapsids + (, 'arch') > () "having a fused arch"; synonymous with ''theropsids'' (Greek, "beast-face") are one of the two major groups of animals that evolved from basal amniotes, the other being the sauropsids, the group that includes reptil ...

s that lived during the

Guadalupian The Guadalupian is the second and middle series/epoch of the Permian. The Guadalupian was preceded by the Cisuralian and followed by the Lopingian. It is named after the Guadalupe Mountains of New Mexico and Texas, and dates between 272.95 ± 0. ...

(= Middle

Permian The Permian ( ) is a geologic period and stratigraphic system which spans 47 million years from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic Period 251.9 Mya. It is the last period of the Paleoz ...

) in what is now the south of

France France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of Overseas France, overseas regions and territories in the Americas and the Atlantic Ocean, Atlantic, Pacific Ocean, Pac ...

. The genus is only known by its

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 ...

, ''Lalieudorhynchus gandi'', which was named in 2022 by Ralf Werneburg, Frederik Spindler, Jocelyn Falconnet, Jean-Sébastien Steyer, Monique Vianey-Liaud, and Joerg W. Schneider. ''Lalieudorhynchus'' is represented by a partial postcranial skeleton discovered in the

Lodève Lodève (; oc, Lodeva ) is a commune in the département of Hérault, in the Occitanie region in southern France. It is a sub-prefecture of the department. The derivation of the city's name is from Gaulish ''Luteva'', composed of lut-, swamp, ...

basin in the central part of the

Hérault Hérault (; oc, Erau, ) is a department of the region of Occitania, Southern France. Named after the Hérault River, its prefecture is Montpellier. It had a population of 1,175,623 in 2019.department Department may refer to: * Departmentalization, division of a larger organization into parts with specific responsibility Government and military *Department (administrative division), a geographical and administrative division within a country, ...

in the

Occitanie Occitanie may refer to: *Occitania, a region in southern France called ''Occitanie'' in French *Occitania (administrative region) Occitania ( ; french: Occitanie ; oc, Occitània ; ca, Occitània ) is the southernmost administrative region of ...

region In geography, regions, otherwise referred to as zones, lands or territories, are areas that are broadly divided by physical characteristics (physical geography), human impact characteristics (human geography), and the interaction of humanity and t ...

. It belongs to an individual measuring approximately in length. The degree of

ossification Ossification (also called osteogenesis or bone mineralization) in bone remodeling is the process of laying down new bone material by cells named osteoblasts. It is synonymous with bone tissue formation. There are two processes resulting in t ...

of its bones, however, indicates that it was a late juvenile or still growing young

adult An adult is a human or other animal that has reached full growth. In human context, the term ''adult'' has meanings associated with social and legal concepts. In contrast to a " minor", a legal adult is a person who has attained the age of major ...

. Based on the internal structure of its bones, the describing authors interpreted ''Lalieudorhynchus'' as a

semiaquatic In biology, semiaquatic can refer to various types of animals that spend part of their time in water, or plants that naturally grow partially submerged in water. Examples are given below. Semiaquatic animals Semiaquatic animals include: * Verte ...

animal that may have had a lifestyle similar to that of

hippopotamus The hippopotamus ( ; : hippopotamuses or hippopotami; ''Hippopotamus amphibius''), also called the hippo, common hippopotamus, or river hippopotamus, is a large semiaquatic mammal native to sub-Saharan Africa. It is one of only two extan ...

, spending part of its time in water but returning to land for food, though the idea that caseids were semi-aquatic has been previously contested by other authors. It is geologically one of the youngest known representatives of the caseids. The

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 ...

proposed by Werneburg and colleagues identified ''Lalieudorhynchus'' as a derived caseid closely related to the

North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...

n species '' "Cotylorhynchus" hancocki''.

Etymology

The genus name is a combination of La Lieude located near the type locality, and "rhynchus", the Latinized form of the Greek "rhynchos" (the nose) sometimes used in the names of caseids. The

specific epithet In taxonomy, binomial nomenclature ("two-term naming system"), also called nomenclature ("two-name naming system") or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, bot ...

honours Georges Gand who worked on the Lodève basin for decades, notably on the La Lieude footprint slab, and co-organized and promoted the excavation campaigns for this caseid.

Description

''Lalieudorhynchus'' is represented by a partial and disarticulated but well-preserved post-cranial skeleton. 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 ...

, represented by a series of bones cataloged UM-LIE 02–37, UM-LIE 39–41, UM-LIE 45 and UM-LIE 47, consists of about ten

vertebra The spinal column, a defining synapomorphy shared by nearly all vertebrates,Hagfish are believed to have secondarily lost their spinal column is a moderately flexible series of vertebrae (singular vertebra), each constituting a characteristic ...

e (

dorsal Dorsal (from Latin ''dorsum'' ‘back’) may refer to: * Dorsal (anatomy), an anatomical term of location referring to the back or upper side of an organism or parts of an organism * Dorsal, positioned on top of an aircraft's fuselage * Dorsal co ...

sacral Sacral may refer to: *Sacred Sacred describes something that is dedicated or set apart for the service or worship of a deity; is considered worthy of spiritual respect or devotion; or inspires awe or reverence among believers. The property ...

and caudal), about fifteen

rib In vertebrate anatomy, ribs ( la, costae) are the long curved bones which form the rib cage, part of the axial skeleton. In most tetrapods, ribs surround the chest, enabling the lungs to expand and thus facilitate breathing by expanding the ches ...

s, a complete right

scapulocoracoid The scapulocoracoid is the unit of the pectoral girdle that contains the coracoid and scapula. The coracoid itself is a beak-shaped bone that is commonly found in most vertebrates with a few exceptions. The scapula is commonly known as the ''shoulde ...

long, the dorsal branch of the left ilium, the right and left

femora 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 t ...

measuring long, and several foot bones (an

astragalus ''Astragalus'' is a large genus of over 3,000 species of herbs and small shrubs, belonging to the legume family Fabaceae and the subfamily Faboideae. It is the largest genus of plants in terms of described species. The genus is native to tempe ...

, two tarsal elements and five

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. ...

). The total body length of this specimen is estimated at . The holotype of ''Lalieudorhynchus'' shows a mixture of mature and immature characters throughout its skeleton indicating that this specimen was a late juvenile or a still growing young

at the time of its death. The

skull The skull is a bone protective cavity for the brain. The skull is composed of four types of bone i.e., cranial bones, facial bones, ear ossicles and hyoid bone. However two parts are more prominent: the cranium and the mandible. In humans, the ...

is unknown, but like its closest relatives, it was probably very small compared to the size of the body, triangular-shaped in dorsal view, and terminating anteriorly in a forward-sloping snout with very large external

nostril A nostril (or naris , plural ''nares'' ) is either of the two orifices of the nose. They enable the entry and exit of air and other gasses through the nasal cavities. In birds and mammals, they contain branched bones or cartilages called turbi ...

s. The shape of its ribs indicates that ''Lalieudorhynchus'' had a barrel-shaped

rib cage The rib cage, as an enclosure that comprises the ribs, vertebral column and sternum in the thorax of most vertebrates, protects vital organs such as the heart, lungs and great vessels. The sternum, together known as the thoracic cage, is a semi- ...

like other derived caseids. This must have housed large

digestive tract The gastrointestinal tract (GI tract, digestive tract, alimentary canal) is the tract or passageway of the digestive system that leads from the mouth to the anus. The GI tract contains all the major organs of the digestive system, in humans a ...

suggesting that the animal had to feed on a large quantity of plants with low nutritional value. ''Lalieudorhynchus'' is characterized by several

apomorphies In phylogenetics, an apomorphy (or derived trait) is a novel character or character state that has evolved from its ancestral form (or plesiomorphy). A synapomorphy is an apomorphy shared by two or more taxa and is therefore hypothesized to have ...

. The

neural spines The spinal column, a defining synapomorphy shared by nearly all vertebrates,Hagfish are believed to have secondarily lost their spinal column is a moderately flexible series of vertebrae (singular vertebra), each constituting a characteristic ...

of the

and anterior

caudal vertebrae The spinal column, a defining synapomorphy shared by nearly all vertebrates,Hagfish are believed to have secondarily lost their spinal column is a moderately flexible series of vertebrae (singular vertebra), each constituting a characteristic ...

have a cross section with a very thin keel-like process forwards, which starting above the

prezygapophyses The articular processes or zygapophyses (Greek language, Greek ζυγον = "yoke" (because it links two vertebrae) + απο = "away" + φυσις = "-physis, process") of a vertebra are projections of the vertebra that serve the purpose of fitting ...

and running upwards along the entire vertical edge to the top of the neural spine. The neural spines of the dorsal and caudal vertebrae have their dorsal end slender instead of showing lateral thickening. The first sacral rib has a narrow

distal Standard anatomical terms of location are used to unambiguously describe the anatomy of animals, including humans. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position pro ...

end. The scapulocoracoid has a fossa on the triceps process of the metacoracoid (one of the three bones forming the scapulocoracoid with the procoracoid and the

scapula The scapula (plural scapulae or scapulas), also known as the shoulder blade, is the bone that connects the humerus (upper arm bone) with the clavicle (collar bone). Like their connected bones, the scapulae are paired, with each scapula on eithe ...

). The foot is characterized by a very large distal tarsus 1 of the same width as the astragalus, with almost all sides slightly concave. ''Lalieudorhynchus'' is also distinguished by a unique combination of characters. Like other caseids, it differs from ''

Ruthenosaurus ''Ruthenosaurus'' is an extinct genus of caseid synapsids that lived in what is now southern France during the Early Permian (late Artinskian) about 285 million years ago. It is known from the holotype MNHN.F.MCL-1 an articulated partial pos ...

'' by its straight neural spines instead of being angled forwards. The middle caudal vertebrae have relatively long

centra Centra is a convenience shop chain that operates throughout Ireland. The chain operates as a symbol group owned by Musgrave Group, the food wholesaler, meaning the stores are all owned by individual franchisees. The chain has three different f ...

, elongated below their

postzygapophyses The articular processes or zygapophyses (Greek ζυγον = "yoke" (because it links two vertebrae) + απο = "away" + φυσις = "process") of a vertebra are projections of the vertebra that serve the purpose of fitting with an adjacent vertebr ...

, but with low neural arches, unlike '' Alierasaurus''. The three sacral vertebrae and the most anterior caudal vertebra have a short and transversely very wide centrum like in ''Ruthenosaurus'', while these same centra are much narrower in ''

Cotylorhynchus romeri ''Cotylorhynchus'' is an extinct genus of herbivorous caseid synapsids that lived during the late Lower Permian (Kungurian) and possibly the early Middle Permian (Roadian) in what is now Texas and Oklahoma in the United States. The large number ...

''. The neural spine of the first sacral and the first caudal vertebra is very elongated dorsally as in '' "Cotylorhynchus" hancocki'', which is not the case in ''C. romeri'' and ''Ruthenosaurus''. A ''

hyposphene The hyposphene-hypantrum articulation is an accessory joint found in the vertebrae of several fossil reptiles of the group Archosauromorpha. It consists of a process on the backside of the vertebrae, the hyposphene, that fits in a depression in the ...

'' is present under the postzygapophyses of the dorsal and caudal vertebrae, a feature previously reported only in ''C. hancocki''. A supraglenoid

foramen In anatomy and osteology, a foramen (;Entry "foramen"
in

is present, opening laterally in the supraglenoid fossa and medially in the dorsal part of the subscapular fossa as in ''"C." hancocki''. The shaft of the scapular blade is much wider than that of ''Alierasaurus''. The anteromedial border of the scapula is bulged by the presence of a slightly rounded scapular process, a feature shared with ''"C." hancocki'', ''"C." bransoni'' and '' "Angelosaurus" romeri'', but not with ''C. romeri'' and ''Alierasaurus''. Two parts of the glenoid fossa have an angle of approximately 130° as in ''C. bransoni''. The femur has a posterior

condyle A condyle (;Entry "condyle"
in
popliteal area of the femur of ''Lalieudorhynchus'' is relatively wide with robust grooves, and is much larger and deeper than in ''C. romeri''. The proximal head of the bone is more massive dorso-ventrally than in ''C. romeri''. The femur also has a large pronounced internal trochanter and a little

fourth trochanter The fourth trochanter is a shared characteristic common to archosaurs. It is a knob-like feature on the posterior-medial side of the middle of the femur shaft that serves as a muscle attachment, mainly for the ''musculus caudofemoralis longus'', ...

in its distal half, a feature shared with ''"C." hancocki'', ''Angelosaurus romeri'' and ''A. greeni'', and which differs from ''C. romeri'', ''Angelosaurus dolani'', '' Casea broilii'', and ''Ruthenosaurus''. The intercondylar fossa of the femur is very wide, inferring a narrow postero-dorsal condyle, unlike ''C. romeri'' and ''Ruthenosaurus''. The astragalus is nearly as broad as long in contrast to most other caseids, but is very similar to that of ''"C." hancocki''. The

metatarsal 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 med ...

I is robust and enlarged like in ''Alierasaurus''. The phalanges are short and wide. They are shorter than in ''Alierasaurus''.

Paleobiology

Rib bone

histology Histology, also known as microscopic anatomy or microanatomy, is the branch of biology which studies the microscopic anatomy of biological tissues. Histology is the microscopic counterpart to gross anatomy, which looks at larger structures vis ...

of ''Lalieudorhynchus'' revealed a bone with a very spongy structure, an extremely thin

cortex Cortex or cortical may refer to: Biology * Cortex (anatomy), the outermost layer of an organ ** Cerebral cortex, the outer layer of the vertebrate cerebrum, part of which is the ''forebrain'' *** Motor cortex, the regions of the cerebral cortex i ...

, and the absence of distinct

medullary cavity 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 m ...

. These characteristics, also reported in other large caseids such as ''Cotylorhynchus'', would suggest a semiaquatic lifestyle. This hypothesis is however disputed by Kenneth Angielczyk and Christian Kammerer, as well as by Robert Reisz and colleagues based on

paleontological Paleontology (), also spelled palaeontology or palæontology, is the scientific study of life that existed prior to, and sometimes including, the start of the Holocene epoch (geology), epoch (roughly 11,700 years before present). It includes t ...

and

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 ...

data combined with the absence in these large caseids of morphological adaptations to an aquatic lifestyle. However, these authors do not yet provide alternative explanations for the internal bone structure of large caseids. Werneburg and colleagues think that ''Lalieudorhynchus'' and large caseids in general, could have had a semiquatic lifestyle comparable to that of

hippopotamuses The hippopotamus ( ; : hippopotamuses or hippopotami; ''Hippopotamus amphibius''), also called the hippo, common hippopotamus, or river hippopotamus, is a large semiaquatic mammal native to sub-Saharan Africa. It is one of only two extant ...

, spending most of their time in water, practicing a kind of subaquatic walking rather than swimming, and possibly returning to land to feed on terrestrial plants. However, paleontologists don't know if ''Lalieudorhynchus'' fed on terrestrial and/or aquatic plants. Plant fossils associated with the skeleton of ''Lalieudorhynchus'' are identified as terrestrial forms adapted to a dry seasonal climate, while aquatic plants are not present. However, the latter are rarely preserved in Permian sites. Sedimentary analysis of the type locality of ''Lalieudorhynchus'' indicates the existence of several potential aquatic habitats. Partially

silt Silt is granular material of a size between sand and clay and composed mostly of broken grains of quartz. Silt may occur as a soil (often mixed with sand or clay) or as sediment mixed in suspension with water. Silt usually has a floury feel when ...

claystone Mudrocks are a class of fine-grained siliciclastic sedimentary rocks. The varying types of mudrocks include siltstone, claystone, mudstone, slate, and shale. Most of the particles of which the stone is composed are less than and are too sm ...

beds to thick come from suspended-sedimentation in a mass of stagnant water after heavy flooding. Some remains of aquatic

arthropod Arthropods (, (gen. ποδός)) are invertebrate animals with an exoskeleton, a Segmentation (biology), segmented body, and paired jointed appendages. Arthropods form the phylum Arthropoda. They are distinguished by their jointed limbs and Arth ...

s adapted to temporary stagnant waters such as

conchostracans Clam shrimp are a group of bivalved branchiopod crustaceans that resemble the unrelated Bivalvia, bivalved molluscs. They are extant and also known from the fossil record, from at least the Devonian period and perhaps before. They were originally ...

and triopsids have been found in these levels. Another possible habitat are river channels reaching to deep in La Lieude Formation. The presence of rooting at several levels indicates that these channels must not have been filled with flowing water all year round because of the seasonal climate of the time. During the dry season, however, it is likely that masses of stagnant water may have existed in abandoned channels, lakes or ponds, allowing the survival of animals with a more aquatic lifestyle such as the tupilakosaurid

dvinosaurs Dvinosaurs are one of several new clades of Temnospondyl amphibians named in the phylogenetic review of the group by Yates and Warren 2000. They represent a group of primitive semi-aquatic to completely aquatic amphibians, and are known from t ...

, of which one specimen was associated with the skeleton of ''Lalieudorhynchus''.

Discovery and taphonomy

The first remains of ''Lalieudorhynchus'' were discovered in 2001 by Joerg W. Schneider and Frank Körner in the Salagou stream during geological field mapping in the Lodève basin. Other elements were recovered during excavations carried out between 2004 and 2008 totaling about fifty bones. The size range of the bones indicates that they come from a single individual. The presence of bones of a single and same individual distributed sporadically in a sequence thick (with a concentration of bones in a bed of thick) within horizons with different

lithology The lithology of a rock unit is a description of its physical characteristics visible at outcrop, in hand or core samples, or with low magnification microscopy. Physical characteristics include colour, texture, grain size, and composition. Lit ...

, could be explained by a decomposition of the carcass in a vegetated area (as suggested by abundant plant remains) alternately exposed and flooded. The bones seem to have been reworked and redeposited several times but over a very short distance and over a very short period of time because the bones are very well preserved. They do not show wear due to transport by water and are not fractured by prolonged exposure to a highly seasonal climate.

Geographical and stratigraphical distribution

The holotype of ''Lalieudorhynchus'' comes from the upper part of the La Lieude Formation, in the

basin located in

, in

. The disarticulated skeleton was discovered in

strata In geology and related fields, a stratum ( : strata) is a layer of rock or sediment characterized by certain lithologic properties or attributes that distinguish it from adjacent layers from which it is separated by visible surfaces known as ei ...

located approximately above the base of the formation (which reaches a total of in thickness). No

radiometric dating Radiometric dating, radioactive dating or radioisotope dating is a technique which is used to date materials such as rocks or carbon, in which trace radioactive impurities were selectively incorporated when they were formed. The method compares t ...

is available for the La Lieude Formation. A

Lopingian The Lopingian is the uppermost series/last epoch of the Permian. It is the last epoch of the Paleozoic. The Lopingian was preceded by the Guadalupian and followed by the Early Triassic. The Lopingian is often synonymous with the informal terms l ...

(= Upper Permian) age was assigned to it by insects

biostratigraphy Biostratigraphy is the branch of stratigraphy which focuses on correlating and assigning relative ages of rock Stratum, strata by using the fossil assemblages contained within them.Hine, Robert. “Biostratigraphy.” ''Oxford Reference: Dictiona ...

, radiometric ages and sedimentation rates calculated for the underlying Salagou Formation. Magnetostratigraphic and paleontological data most likely suggest a Guadalupian (= Middle Permian) age.

Magnetostratigraphy Magnetostratigraphy is a geophysical correlation technique used to date sedimentary and volcanic sequences. The method works by collecting oriented samples at measured intervals throughout the section. The samples are analyzed to determine their '' ...

indicates that the lower part of the La Lieude Formation is no younger than the Illawarra Reversal, a global geomagnetic event dated to the Middle

Wordian In the geologic timescale, the Wordian is an age or stage of the Permian. It is the middle of three subdivisions of the Guadalupian Epoch or Series. The Wordian lasted between and million years ago (Ma). It was preceded by the Roadian and foll ...

266.66 ± 0.76 million years ago. Therefore, this part of the formation would probably have a late

Roadian In the geologic timescale, the Roadian is an age or stage of the Permian. It is the earliest or lower of three subdivisions of the Guadalupian Epoch or Series. The Roadian lasted between and million years ago (Ma). It was preceded by the Kung ...

– early

age, while the upper part would have a minimum late Wordian – early

Capitanian In the geologic timescale, the Capitanian is an age or stage of the Permian. It is also the uppermost or latest of three subdivisions of the Guadalupian Epoch or Series. The Capitanian lasted between and million years ago. It was preceded by th ...

age. The presence in the lower part of the La Lieude Formation of the

ichnogenus An ichnotaxon (plural ichnotaxa) is "a taxon based on the fossilized work of an organism", i.e. the non-human equivalent of an artifact. ''Ichnotaxa'' comes from the Greek ίχνος, ''ichnos'' meaning ''track'' and ταξις, ''taxis'' meaning ...

'' Brontopus'' also indicates a Guadalupian age. Originally discovered at La Lieude, ''Brontopus'' has since been found in the Abrahamskraal Formation in

South Africa South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. It is bounded to the south by of coastline that stretch along the South Atlantic and Indian Oceans; to the north by the neighbouring countri ...

which is radiometrically dated to Wordian and Capitanian. The presumed producers of the ''Brontopus'' tracks, the

dinocephalia Dinocephalians (terrible heads) are a clade of large-bodied early therapsids that flourished in the Early and Middle Permian between 279.5 and 260 million years ago (Ma), but became extinct during the Capitanian mass extinction event. Dinoceph ...

therapsid Therapsida is a major group of eupelycosaurian synapsids that includes mammals, their ancestors and relatives. Many of the traits today seen as unique to mammals had their origin within early therapsids, including limbs that were oriented more ...

s, are also consistent with a Guadalupian age of the La Lieude Formation because the bones of these animals, discovered in

Southern Southern may refer to: Businesses * China Southern Airlines, airline based in Guangzhou, China * Southern Airways, defunct US airline * Southern Air, air cargo transportation company based in Norwalk, Connecticut, US * Southern Airways Express, M ...

and

eastern Africa East Africa, Eastern Africa, or East of Africa, is the eastern subregion of the African continent. In the United Nations Statistics Division scheme of geographic regions, 10-11-(16*) territories make up Eastern Africa: Due to the historical ...

as well as in

Russia Russia (, , ), or the Russian Federation, is a List of transcontinental countries, transcontinental country spanning Eastern Europe and North Asia, Northern Asia. It is the List of countries and dependencies by area, largest country in the ...

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 ...

and

Brazil Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area ...

, are exclusively known in Guadalupian deposits. The Wordian - Capitanian age of ''Lalieudorhynchus'' makes it one of the last known caseids. With the genera ''

Ennatosaurus ''Ennatosaurus'' is an extinct genus of caseid synapsid that lived during the Middle Permian (late Roadian - early Wordian) in northern European Russia. The genus is only represented by its type species, ''Ennatosaurus tecton'', which was named i ...

'' and '' Alierasaurus'', it confirms the persistence of caseids during the Guadalupian at least in Europe.

Paleoenvironments

In Guadalupian time, most of the landmasses were united in one supercontinent,

Pangea Pangaea or Pangea () was a supercontinent that existed during the late Paleozoic and early Mesozoic eras. It assembled from the earlier continental units of Gondwana, Euramerica and Siberia during the Carboniferous approximately 335 million y ...

. It was roughly C-shaped: its northern (

Laurasia Laurasia () was the more northern of two large landmasses that formed part of the Pangaea supercontinent from around ( Mya), the other being Gondwana. It separated from Gondwana (beginning in the late Triassic period) during the breakup of Pan ...

) and southern (

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 ...

) parts were connected to the west, but separated to the east by the very large

Tethys Sea The Tethys Ocean ( el, Τηθύς ''Tēthús''), also called the Tethys Sea or the Neo-Tethys, was a prehistoric ocean that covered most of the Earth during much of the Mesozoic Era and early Cenozoic Era, located between the ancient continents ...

. A long string of microcontinents, grouped under the name of Cimmeria, divided the Tethys in two : the Paleo-Tethys in the north, and the Neo-Tethys in the south. The Lodève basin was located in the equatorial belt of the time, at the level of the

10th parallel north The 10th parallel north is a circle of latitude that is 10 degrees north of the Earth's equatorial plane. It crosses Africa, the Indian Ocean, the Indian Subcontinent, Southeast Asia, the Pacific Ocean, Central America, South America and the A ...

, and in relation to the Tethys shores, was approximately 400 km inland. Hercynian mounts, with unknown topography, separated the Lodève basin from the Tethys. At that time, the very humid climate which usually characterizes the

equatorial climate A tropical rainforest climate, humid tropical climate or equatorial climate is a tropical climate sub-type usually found within 10 to 15 degrees latitude of the equator. There are some other areas at higher latitudes, such as the coast of southeas ...

had been replaced by an extension of the drier tropical climate (with two seasons, dry and wet) toward the regions close to the equator. The La Lieude Formation is represented by conglomerates, fine to coarse-grained, partly pebbly

sandstone Sandstone is a clastic sedimentary rock composed mainly of sand-sized (0.0625 to 2 mm) silicate grains. Sandstones comprise about 20–25% of all sedimentary rocks. Most sandstone is composed of quartz or feldspar (both silicates) ...

s, red-brown, partly clayey or fine sandy

siltstone Siltstone, also known as aleurolite, is a clastic sedimentary rock that is composed mostly of silt. It is a form of mudrock with a low clay mineral content, which can be distinguished from shale by its lack of fissility.Blatt ''et al.'' 1980, p ...

s, and intercalated silty

s. These rocks correspond to

sand Sand is a granular material composed of finely divided mineral particles. Sand has various compositions but is defined by its grain size. Sand grains are smaller than gravel and coarser than silt. Sand can also refer to a textural class of s ...

gravel Gravel is a loose aggregation of rock fragments. Gravel occurs naturally throughout the world as a result of sedimentary and erosive geologic processes; it is also produced in large quantities commercially as crushed stone. Gravel is classifi ...

s, and

pebble A pebble is a clast of rock with a particle size of based on the Udden-Wentworth scale of sedimentology. Pebbles are generally considered larger than granules ( in diameter) and smaller than cobbles ( in diameter). A rock made predominant ...

s carried by rivers, and to

fluvial In geography and geology, fluvial processes are associated with rivers and streams and the deposits and landforms created by them. When the stream or rivers are associated with glaciers, ice sheets, or ice caps, the term glaciofluvial or fluviog ...

s from

floodplain A floodplain or flood plain or bottomlands is an area of land adjacent to a river which stretches from the banks of its channel to the base of the enclosing valley walls, and which experiences flooding during periods of high discharge.Goudi ...

s, deposited in a

braided river A braided river, or braided channel, consists of a network of river channels separated by small, often temporary, islands called braid bars or, in English usage, ''aits'' or ''eyots''. Braided streams tend to occur in rivers with high sediment l ...

system. There are also several

debris flow Debris flows are geological phenomena in which water-laden masses of soil and fragmented rock rush down mountainsides, funnel into stream channels, entrain objects in their paths, and form thick, muddy deposits on valley floors. They generally ...

layers testifying the existence of very heavy rainfall during the wet season. Most of the bones of ''Lalieudorhynchus'' come from these debris flow horizons and some from mudflows. These debris flow deposits also contain abundant plant remains represented by numerous lanceolate leaves in length probably belonging to ''Plagiozamites'', some remains of ''

Podozamites ''Podozamites'' is an extinct genus of fossil conifer leaves. In its broader sense, it has been used as a morphogenus (Form classification, form taxon) to refer to any broad leaved multi-veined conifer leaves. Modern broad-leaved conifers with a ...

''-like coniferophytes, ''

Supaia ''Supaia'' is an extinct genus of fern-like plants, possibly seed ferns. Species belonging to the genus lived during the Permian The Permian ( ) is a geologic period and stratigraphic system which spans 47 million years from the end of the ...

''-like fragments, a few tree trunks up to long and wide, and smaller plant axes. Apart from ''Lalieudorhynchus'', the upper part of the Lieude Formation yielded only a

vertebral column The vertebral column, also known as the backbone or spine, is part of the axial skeleton. The vertebral column is the defining characteristic of a vertebrate in which the notochord (a flexible rod of uniform composition) found in all chordata, ...

of a tupilakosaurid

temnospondyl Temnospondyli (from Greek language, Greek τέμνειν, ''temnein'' 'to cut' and σπόνδυλος, ''spondylos'' 'vertebra') is a diverse order (biology), order of small to giant tetrapods—often considered Labyrinthodontia, primitive amphi ...

, freshwater arthropods (conchostracans and triopsids), insect wings (

Odonata Odonata is an order of flying insects that includes the dragonflies and damselflies. Members of the group first appeared during the Triassic, though members of their total group, Odonatoptera, first appeared in Late Carboniferous. The two comm ...

), and indeterminable footprints. Other elements of the fauna of the La Lieude Formation are present on the La Lieude slab, located towards the base of the formation, which exposes numerous

tetrapod Tetrapods (; ) are four-limbed vertebrate animals constituting the superclass Tetrapoda (). It includes extant and extinct amphibians, sauropsids ( reptiles, including dinosaurs and therefore birds) and synapsids (pelycosaurs, extinct theraps ...

trackways. Many tetrapod

ichnospecies An ichnotaxon (plural ichnotaxa) is "a taxon based on the fossilized work of an organism", i.e. the non-human equivalent of an artifact. ''Ichnotaxa'' comes from the Greek ίχνος, ''ichnos'' meaning ''track'' and ταξις, ''taxis'' meaning ...

have been named from this site. The

taxonomic Taxonomy is the practice and science of categorization or classification. A taxonomy (or taxonomical classification) is a scheme of classification, especially a hierarchical classification, in which things are organized into groups or types. ...

and morphological review of these footprints distinguished four valid ichnospecies and identified their probable producers: '' Brontopus giganteus'' and ''B. antecursor'', which very probably represents

s (respectively a

Tapinocephalia The Tapinocephalia are one of the major groups of dinocephalian therapsids and the major herbivorous group. Tapinocephalia has been found to consist of three clades: Styracocephalidae, Titanosuchidae, and the very successful Tapinocephalidae. No ...

and an

Anteosauridae Anteosauridae is an extinct family of large carnivorous dinocephalian therapsids that are known from the Middle Permian of Asia, Africa, and South America.These animals were by far the largest predators of the Permian period, with skulls reaching ...

), ''Merifontichnus thalerius'', which corresponds to footprints of a moradisaurin

captorhinid Captorhinidae (also known as cotylosaurs) is an extinct family of tetrapods, traditionally considered primitive reptiles, known from the late Carboniferous to the Late Permian. They had a cosmopolitan distribution across Pangea. Description Cap ...

eureptile Eureptilia ("true reptiles") is one of the two major subgroups of the clade Sauropsida, the other one being Parareptilia. Eureptilia includes Diapsida (the clade containing all modern reptiles and birds), as well as a number of primitive Permo ...

, and ''Pachypes ollieri'', which would belong to a

pareiasauromorpha Pareiasauromorpha is a group of parareptilian amniotes from the Permian. It includes genera found all over the world, with many genera from Asia and South Africa. The clade was first used as a group by Linda A. Tsuji in 2011, in order to grou ...

Nycteroleteridae Nycteroleteridae is a family of procolophonian parareptilians (extinct early reptiles) from the Middle to Late Permian of Russia and North America. They are sometimes classified as a sister group to pareiasaurids (but see ''Classification)''. Th ...

Phylogeny

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 ...

by Wernebug and colleagues identified ''Lalieudorhynchus gandi'' as one of the most derived caseids and the

sister taxon In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises the closest relative(s) of another given unit in an evolutionary tree. Definition The expression is most easily illustrated by a cladogram: Taxon A and t ...

to the North American species '' "Cotylorhynchus" hancocki''. These two

taxa In biology, a taxon (back-formation from ''taxonomy''; plural taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular nam ...

form a

clade A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English term, ...

characterized by the presence of a ''hyposphene'', as well as by the presence and position of the supraglenoid foramen. This clade forms with ''"Cotylorhynchus" bransoni'' an apical clade characterized by closely spaced postzygapophyses. This analysis also suggests that the genera ''Angelosaurus'' and ''Cotylorhynchus'' (each composed of three species) would be

paraphyletic In taxonomy (general), taxonomy, a group is paraphyletic if it consists of the group's most recent common ancestor, last common ancestor and most of its descendants, excluding a few Monophyly, monophyletic subgroups. The group is said to be pa ...

, taxa other than their type species may belong to different

genera Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nomenclat ...

. Below is the cladogram published by Werneburg and colleagues in 2022.

Notes

References

{{Reflist, 2 Caseasaurs Guadalupian synapsids of Europe Permian synapsids of Europe Guadalupian synapsids Prehistoric synapsid genera Fossil taxa described in 2022 Fossils of France