This list of

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserve ...

reptile Reptiles, as commonly defined, are a group of tetrapods with an ectothermic metabolism and Amniotic egg, amniotic development. Living traditional reptiles comprise four Order (biology), orders: Testudines, Crocodilia, Squamata, and Rhynchocepha ...

s described in 2021 is a list of new

taxa In biology, a taxon (back-formation from ''taxonomy''; : 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 name and ...

of fossil reptiles that were described during the year 2021, as well as other significant discoveries and events related to reptile

paleontology Paleontology, also spelled as palaeontology or palæontology, is the scientific study of the life of the past, mainly but not exclusively through the study of fossils. Paleontologists use fossils as a means to classify organisms, measure ge ...

that occurred in 2021.

Squamates

New squamate taxa

Research

* A study on the evolution of tooth complexity in

squamates Squamata (, Latin ''squamatus'', 'scaly, having scales') is the largest order of reptiles; most members of which are commonly known as lizards, with the group also including snakes. With over 11,991 species, it is also the second-largest order ...

, based on data from extant and fossil taxa, is published by Lafuma ''et al.'' (2021). * A study on the diversity of jaw sizes, lower jaw shape and morphology of teeth in Cretaceous squamates is published by Herrera-Flores, Stubbs & Benton (2021), who interpret their findings as indicating that a substantial expansion of

ecomorphological Ecomorphology or ecological morphology is the study of the relationship between the ecological role of an individual and its morphological adaptations. The term "morphological" here is in the anatomical context. Both the morphology and ecology ex ...

diversity of squamates occurred in the mid-Cretaceous, 110–90 Ma, before the first rise in taxonomic diversity of this group in the

Campanian The Campanian is the fifth of six ages of the Late Cretaceous epoch on the geologic timescale of the International Commission on Stratigraphy (ICS). In chronostratigraphy, it is the fifth of six stages in the Upper Cretaceous Series. Campa ...

. * A study on the dietary preferences of lizards from the Upper Cretaceous Iharkút vertebrate locality (

Hungary Hungary is a landlocked country in Central Europe. Spanning much of the Pannonian Basin, Carpathian Basin, it is bordered by Slovakia to the north, Ukraine to the northeast, Romania to the east and southeast, Serbia to the south, Croatia and ...

) is published by Gere ''et al.'' (2021). * A study on the locomotion of five Cretaceous lizards, and on its implications for the knowledge of the ancestral locomotion type in lizards, is published by Villaseñor-Amador, Suárez & Cruz (2021), who interpret their findings as indicating that ''

Huehuecuetzpalli ''Huehuecuetzpalli'' (translating to "the ancient lizard" in Nahuatl) is an extinct genus of lizard from the Early Cretaceous (late Albian) Tlayúa Formation, a Lagerstätte near Tepexi de Rodríguez, Central Mexico. One species, ''H. mixectus' ...

mixtecus'' was bipedal while '' Tijubina pontei'' was facultatively bipedal. * Augé, Dion & Phélizon (2021) describe the lizard fauna from the

Paleocene The Paleocene ( ), or Palaeocene, is a geological epoch (geology), epoch that lasted from about 66 to 56 mya (unit), million years ago (mya). It is the first epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), ...

locality of Montchenot (

Paris Basin The Paris Basin () is one of the major geological regions of France. It developed since the Triassic over remnant uplands of the Variscan orogeny (Hercynian orogeny). The sedimentary basin, no longer a single drainage basin, is a large sag in ...

France France, officially the French Republic, is a country located primarily in Western Europe. Overseas France, Its overseas regions and territories include French Guiana in South America, Saint Pierre and Miquelon in the Atlantic Ocean#North Atlan ...

), and evaluate the implications of this fauna for the knowledge of diversity changes of European squamate faunas across the Paleocene/Eocene boundary. * Čerňanský ''et al.'' (2021) describe new fossil material of lizards from two Miocene sites in Kutch (Gujarat,

India India, officially the Republic of India, is a country in South Asia. It is the List of countries and dependencies by area, seventh-largest country by area; the List of countries by population (United Nations), most populous country since ...

), providing new information on the composition and

biogeography Biogeography is the study of the species distribution, distribution of species and ecosystems in geography, geographic space and through evolutionary history of life, geological time. Organisms and biological community (ecology), communities o ...

of South Asian lizard faunas during the Miocene. * Revision of the fossil material of lizards and snakes from the Miocene of the Saint-Gérand-le-Puy area (

), including the first records of '' Ophisaurus holeci'' and the gallotiine

lacertid The Lacertidae are the family of the wall lizards, true lizards, or sometimes simply lacertas, which are native to Afro-Eurasia. It is a diverse family with at about 360 species in 39 genera. They represent the dominant group of reptiles found i ...

'' Janosikia'' from France, is published by Georgalis & Scheyer (2021). * A study on the fossil record of lizards and snakes from the

Guadeloupe Guadeloupe is an Overseas departments and regions of France, overseas department and region of France in the Caribbean. It consists of six inhabited islands—Basse-Terre Island, Basse-Terre, Grande-Terre, Guadeloupe, Grande-Terre, Marie-Galant ...

Islands, assessing their evolutionary history and diversity over the past 40,000 years, is published by Bochaton ''et al.'' (2021), who interpret their findings as indicative of a massive extinction of Guadeloupe's snakes and lizards following European colonization, preceded by thousands of years of coexistence with earlier Indigenous populations. * A study on the shape and size variation in the

maxilla In vertebrates, the maxilla (: maxillae ) is the upper fixed (not fixed in Neopterygii) bone of the jaw formed from the fusion of two maxillary bones. In humans, the upper jaw includes the hard palate in the front of the mouth. The two maxil ...

e of extant New Zealand diplodactylids, and on its implications for the knowledge of the affinities of

subfossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

diplodactylid remains, is published by Scarsbrook ''et al.'' (2021). * A study aiming to assess the phylogenetic value of lacertid jaw elements from four Oligocene localities in France, and evaluating their implications for the knowledge of the lacertid species richness in the Oligocene, is published by Wencker ''et al.'' (2021). * A study on the

osteological Osteology () is the scientific study of bones, practiced by osteologists . A subdiscipline of anatomy, anthropology, archaeology and paleontology, osteology is the detailed study of the structure of bones, skeletal elements, teeth, microbone morp ...

variability in extant species of lacertid lizards, and on its implications for species delimitation in fossil lacertids, is published by Tschopp ''et al.'' (2021). * Fossils of ''

Gallotia goliath ''Gallotia goliath'' (the Tenerife giant lizard or goliath Tenerife lizard) is an extinct giant lizard species from the island of Tenerife of the Canary Islands, Spain. This reptile lived before the arrival of humans and is believed to have gro ...

'' are described for the first time from the

El Hierro El Hierro (), nicknamed ''Isla del Meridiano'' (the "Meridian Island"), is the farthest south and west of the Canary Islands (an autonomous community of Spain), in the Atlantic Ocean off the coast of Africa, with a population of 11,659 (2023). ...

island (

Canary Islands The Canary Islands (; ) or Canaries are an archipelago in the Atlantic Ocean and the southernmost Autonomous communities of Spain, Autonomous Community of Spain. They are located in the northwest of Africa, with the closest point to the cont ...

) by Palacios-García ''et al.'' (2021), providing the first evidence of the possible coexistence of two giant fossil species of ''

Gallotia The genus ''Gallotia'' are the lacertids (wall lizards) of the Canary Islands. This genus consists of a group that has been evolving there ever since the first islands emerged from the sea over 20 million years ago. The endemic species and sub ...

'' on the same island. * Fossil material of a large

anguimorph The Anguimorpha is a suborder of squamates. The group was named by Fürbringer in 1900 to include all autarchoglossans closer to '' Varanus'' and ''Anguis'' than ''Scincus''. These lizards, along with iguanians and snakes, constitute the propose ...

lizard, possibly a member of Varaniformes and potentially one of the largest Mesozoic terrestrial lizards, is described from the Upper Cretaceous (Maastrichtian) Basturs-1 site (

Spain Spain, or the Kingdom of Spain, is a country in Southern Europe, Southern and Western Europe with territories in North Africa. Featuring the Punta de Tarifa, southernmost point of continental Europe, it is the largest country in Southern Eur ...

) by Cabezuelo Hernández ''et al.'' (2021). * A study on the anatomy and phylogenetic relationships of ''

Tetrapodophis ''Tetrapodophis'' (Greek meaning "four-footed snake") is an extinct genus of lizard from the Early Cretaceous (Aptian) aged Crato Formation of Brazil. It has an elongated snake-like body, with four disproportionately short limbs. ''Tetrapodophi ...

amplectus'' is published by Caldwell ''et al.'' (2021), who reinterpret this squamate as a dolichosaur. * A yaguarasaurine

mosasaur Mosasaurs (from Latin ''Mosa'' meaning the 'Meuse', and Ancient Greek, Greek ' meaning 'lizard') are an extinct group of large aquatic reptiles within the family Mosasauridae that lived during the Late Cretaceous. Their first fossil remains wer ...

oid is reported from the

Cenomanian The Cenomanian is, in the International Commission on Stratigraphy's (ICS) geological timescale, the oldest or earliest age (geology), age of the Late Cretaceous epoch (geology), Epoch or the lowest stage (stratigraphy), stage of the Upper Cretace ...

Turonian The Turonian is, in the International Commission on Stratigraphy, ICS' geologic timescale, the second age (geology), age in the Late Cretaceous epoch (geology), Epoch, or a stage (stratigraphy), stage in the Upper Cretaceous series (stratigraphy), ...

beds of

Coahuila Coahuila, formally Coahuila de Zaragoza, officially the Free and Sovereign State of Coahuila de Zaragoza, is one of the 31 states of Mexico. The largest city and State Capital is the city of Saltillo; the second largest is Torreón and the thi ...

(

Mexico Mexico, officially the United Mexican States, is a country in North America. It is the northernmost country in Latin America, and borders the United States to the north, and Guatemala and Belize to the southeast; while having maritime boundar ...

) by Jiménez-Huidobro ''et al.'' (2021), representing the earliest occurrence of a non-

aigialosaur Aigialosauridae (from Greek, ''aigialos'', meaning "seashore", and ''sauros'', "lizard") is a family of Late Cretaceous semiaquatic pythonomorph lizards closely related to the mosasaurs. Regarded by some paleontologists as a distinct monophyleti ...

mosasauroid from North America reported to date. * Redescription and a study on the geographic provenance of the fossil material of ''"

Liodon ''Liodon'' is a dubious genus of mosasaur from the Late Cretaceous, known from fragmentary fossils discovered in St James' Pit, England and possibly also the Ouled Abdoun Basin of Morocco. Though dubious and of uncertain phylogenetic affinities, ...

" asiaticum'' is published by Bardet ''et al.'' (2021). * One to seven month-long life histories of specimens of ''

Platecarpus ''Platecarpus'' ("oar wrist") is an extinct genus of aquatic lizards belonging to the mosasaur family, living around 84–81 million years ago during the middle Santonian to early Campanian, of the Late Cretaceous period. Fossils have been found ...

tympaniticus'' and ''

Clidastes ''Clidastes'' is an extinct genus of marine lizard belonging to the mosasaur family. It is classified as part of the Mosasaurinae subfamily, alongside genera like ''Mosasaurus'' and ''Prognathodon''. ''Clidastes'' is known from deposits ranging i ...

propython'' collected from chalk deposits of the

Western Interior Seaway The Western Interior Seaway (also called the Cretaceous Seaway, the Niobraran Sea, the North American Inland Sea, or the Western Interior Sea) was a large inland sea (geology), inland sea that existed roughly over the present-day Great Plains of ...

and

Mississippi Embayment The Mississippi embayment is a physiographic feature in the south-central United States, part of the Mississippi Alluvial Plain. It is essentially a northward continuation of the fluvial sediments of the Mississippi River Delta to its conflu ...

Kansas Kansas ( ) is a landlocked U.S. state, state in the Midwestern United States, Midwestern region of the United States. It borders Nebraska to the north; Missouri to the east; Oklahoma to the south; and Colorado to the west. Kansas is named a ...

and

Alabama Alabama ( ) is a U.S. state, state in the Southeastern United States, Southeastern and Deep South, Deep Southern regions of the United States. It borders Tennessee to the north, Georgia (U.S. state), Georgia to the east, Florida and the Gu ...

are reconstructed by Travis Taylor ''et al.'' (2021), who interpret their findings as indicative of semi-regular travels of these mosasaurs from marine to freshwater coastal environments and consumption of freshwater. * Fossil material providing the first evidence of the presence of ''

Plotosaurus ''Plotosaurus'' ("swimmer lizard") is an extinct genus of large mosasaurs which lived during the Upper Cretaceous (Maastrichtian) in what is now North America. The taxon was initially described by University of California, Berkeley, Berkeley pale ...

''-type mosasaurs in the Northwestern Pacific Ocean reported to date is described from the

Hiraiso Formation and

Maastrichtian The Maastrichtian ( ) is, in the International Commission on Stratigraphy (ICS) geologic timescale, the latest age (geology), age (uppermost stage (stratigraphy), stage) of the Late Cretaceous epoch (geology), Epoch or Upper Cretaceous series (s ...

Isoai Formation (

Japan Japan is an island country in East Asia. Located in the Pacific Ocean off the northeast coast of the Asia, Asian mainland, it is bordered on the west by the Sea of Japan and extends from the Sea of Okhotsk in the north to the East China Sea ...

) by Kato ''et al.'' (2021). * First confirmed non-dental mosasaur remains from the

Breien Member of the

Hell Creek Formation The Hell Creek Formation is an intensively studied division of mostly Upper Cretaceous and some lower Paleocene rocks in North America, named for exposures studied along Hell Creek, near Jordan, Montana. The Formation (stratigraphy), formation s ...

(

North Dakota North Dakota ( ) is a U.S. state in the Upper Midwest, named after the indigenous Dakota people, Dakota and Sioux peoples. It is bordered by the Canadian provinces of Saskatchewan and Manitoba to the north and by the U.S. states of Minneso ...

, United States) are described by Van Vranken & Boyd (2021). * A study on the evolutionary history of snakes, aiming to determine possible impact of the

Cretaceous–Paleogene extinction event The Cretaceous–Paleogene (K–Pg) extinction event, also known as the K–T extinction, was the extinction event, mass extinction of three-quarters of the plant and animal species on Earth approximately 66 million years ago. The event cau ...

on the evolution and dispersal of snakes, is published by Klein ''et al.'' (2021). * An assemblage of vertebrae of ''

Palaeophis ''Palaeophis'' ('ancient snake') is an extinct genus of marine snake that is the type genus of the extinct snake family Palaeophiidae. Described species within this genus lived in the Eocene epoch, with some unnamed or questionable records from ...

africanus'', representing the most abundant material of this snake reported to date and providing new information on its anatomy, is described from the Eocene (

Lutetian The Lutetian is, in the geologic timescale, a stage (stratigraphy), stage or age (geology), age in the Eocene. It spans the time between . The Lutetian is preceded by the Ypresian and is followed by the Bartonian. Together with the Bartonian it ...

) of

Togo Togo, officially the Togolese Republic, is a country in West Africa. It is bordered by Ghana to Ghana–Togo border, the west, Benin to Benin–Togo border, the east and Burkina Faso to Burkina Faso–Togo border, the north. It is one of the le ...

by Georgalis ''et al.'' (2021). * A vertebra of ''

Naja romani ''Naja romani'' is an extinct species of cobra from the Miocene of Europe. Its remains have been found from France to Russia and suggest a continued growth to larger sizes throughout its range in time. While successful during the early and middle ...

'' is described from the Miocene (

Turolian The Turolian age is a period of geologic time (9.0–5.3 Ma) within the Miocene used more specifically with European Land Mammal Ages. It precedes the Ruscinian age and follows the Vallesian age. The Turolian overlaps the Tortonian and Messinia ...

) Solnechnodolsk locality (Northern Caucasus, Russia) by Syromyatnikova, Tesakov & Titov (2021), representimg the latest known record of this species and expanding its geographic and geological range. * Biton & Bailon (2021) report the discovery of fossil material of adders belonging to the ''

Bitis arietans The puff adder (''Bitis arietans'') is a highly venomous viper species found in savannahs and grasslands from Morocco and western Arabia throughout Africa except for the Sahara and rainforest regions. It is responsible for causing the most snak ...

'' complex from the early Late Pleistocene of the

Qafzeh cave Qafzeh Cave (Hebrew: , Arabic: ) also known by other names, is a prehistoric archaeological site located at the bottom of Mount Precipice in the Jezreel Valley of Lower Galilee south of Nazareth, Israel. Important remains of prehistoric people w ...

(

Israel Israel, officially the State of Israel, is a country in West Asia. It Borders of Israel, shares borders with Lebanon to the north, Syria to the north-east, Jordan to the east, Egypt to the south-west, and the Mediterranean Sea to the west. Isr ...

), representing the northernmost record of the expansion of these adders outside Africa reported to date, and evaluate the implications of this finding for the knowledge of the climatic and environmental conditions in the surroundings of the Qafzeh Cave during the

Mousterian The Mousterian (or Mode III) is an Industry (archaeology), archaeological industry of Lithic technology, stone tools, associated primarily with the Neanderthals in Europe, and with the earliest anatomically modern humans in North Africa and We ...

''Homo sapiens'' occupations.

Ichthyosauromorphs

New taxa

Research

* Description of anatomy of the palate of ''

Chaohusaurus ''Chaohusaurus'' is an extinct genus of basal ichthyosauriform, depending on definition possibly ichthyosaur, from the Early Triassic of Chaohu and Yuanan, China. Discovery and naming The type species ''Chaohusaurus geishanensis'' was name ...

brevifemoralis'' is published by Yin, Ji & Zhou (2021). * A study on the anatomy of the skull of the

holotype A holotype (Latin: ''holotypus'') is a single physical example (or illustration) of an organism used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of s ...

specimen of ''

Besanosaurus ''Besanosaurus'' (meaning ) is an extinct genus of Middle Triassic ichthyosaur from Monte San Giorgio of Italy and Switzerland, containing the single species ''B. leptorhynchus''. ''Besanosaurus'' was named by Cristiano Dal Sasso and Giovanni Pin ...

leptorhynchus'', description of additional specimens from the

Middle Triassic In the geologic timescale, the Middle Triassic is the second of three epoch (geology), epochs of the Triassic period (geology), period or the middle of three series (stratigraphy), series in which the Triassic system (stratigraphy), system is di ...

Besano Formation The Besano Formation is a geological formation in the southern Alps of northwestern Italy and southern Switzerland. This formation, a thin but fossiliferous succession of Dolomite (rock), dolomite and Shale, black shale, is famous for its preserva ...

(

Italy Italy, officially the Italian Republic, is a country in Southern Europe, Southern and Western Europe, Western Europe. It consists of Italian Peninsula, a peninsula that extends into the Mediterranean Sea, with the Alps on its northern land b ...

Switzerland Switzerland, officially the Swiss Confederation, is a landlocked country located in west-central Europe. It is bordered by Italy to the south, France to the west, Germany to the north, and Austria and Liechtenstein to the east. Switzerland ...

) and a study on the phylogenetic relationships of this species is published by Bindellini ''et al.'' (2021), who interpret '' Mikadocephalus gracilirostris'' as a

junior synonym In taxonomy, the scientific classification of living organisms, a synonym is an alternative scientific name for the accepted scientific name of a taxon. The botanical and zoological codes of nomenclature treat the concept of synonymy differently. ...

of ''B. leptorhynchus''. * New stenopterygiid

ichthyosaur Ichthyosauria is an order of large extinct marine reptiles sometimes referred to as "ichthyosaurs", although the term is also used for wider clades in which the order resides. Ichthyosaurians thrived during much of the Mesozoic era; based on fo ...

fossils, representing some of the best preserved

Toarcian The Toarcian is, in the International Commission on Stratigraphy, ICS' geologic timescale, an age (geology), age and stage (stratigraphy), stage in the Early Jurassic, Early or Lower Jurassic. It spans the time between 184.2 Megaannum, Ma (million ...

specimens from Europe (including a specimen with possible soft tissue preservation), are described from south-east

by Martin ''et al.'' (2021), who also attempt to determine the causes of the state of preservation of the studied specimens, and evaluate the implications of the study site for the knowledge of the environmental perturbations associated with the

Toarcian Oceanic Anoxic Event The Toarcian extinction event, also called the Pliensbachian-Toarcian extinction event, the Early Toarcian mass extinction, the Early Toarcian palaeoenvironmental crisis, or the Jenkyns Event, was an extinction event that occurred during the early ...

. * A specimen of ''

Ichthyosaurus ''Ichthyosaurus'' (derived from Greek () meaning 'fish' and () meaning 'lizard') is a genus of ichthyosaurs from the Early Jurassic (Hettangian - Pliensbachian) of Europe (Belgium, England, Germany and Portugal). Some specimens of the ichthy ...

'' belonging or related to the species ''I. communis'' is identified from the

Sinemurian In the geologic timescale, the Sinemurian is an age (geology), age and stage (stratigraphy), stage in the Early Jurassic, Early or Lower Jurassic epoch (geology), Epoch or series (stratigraphy), Series. It spans the time between 199.5 ±0.3 annu ...

Coimbra Formation (

Portugal Portugal, officially the Portuguese Republic, is a country on the Iberian Peninsula in Southwestern Europe. Featuring Cabo da Roca, the westernmost point in continental Europe, Portugal borders Spain to its north and east, with which it share ...

) by Sousa & Mateus (2021), representing the southernmost occurrence of ''Ichthyosaurus'' reported to date. * A study on the anatomy of narial structures in Early Jurassic ichthyosaurs, and on their implications for the knowledge of the evolution of the bony subdivision of the external naris in more derived ichthyosaurs, is published by Massare, Wahl & Lomax (2021). * The first unambiguous ichthyosaur remains from Antarctica reported to date are described from the Upper Jurassic Ameghino (=Nordenskjöld) Formation by Campos ''et al.'' (2021), who also revise remains of two ichthyosaur specimens from the Upper Jurassic of

Madagascar Madagascar, officially the Republic of Madagascar, is an island country that includes the island of Madagascar and numerous smaller peripheral islands. Lying off the southeastern coast of Africa, it is the world's List of islands by area, f ...

, and describe a third specimen which is the most complete ichthyosaur from this region of

Gondwana Gondwana ( ; ) was a large landmass, sometimes referred to as a supercontinent. The remnants of Gondwana make up around two-thirds of today's continental area, including South America, Africa, Antarctica, Australia (continent), Australia, Zea ...

land. * A study aiming to determine whether

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 143.1 to 66 mya (unit), million years ago (Mya). It is the third and final period of the Mesozoic Era (geology), Era, as well as the longest. At around 77.1 million years, it is the ...

ichthyosaur remains from

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

can be attributed to the species ''

Platypterygius ''Platypterygius'' is a historically paraphyletic genus of platypterygiine ichthyosaur from the Cretaceous period. It was historically used as a wastebasket taxon, and most species within ''Platypterygius'' likely are undiagnostic at the genus or ...

australis'' on the basis of vertebral data alone is published by Vakil, Webb & Cook (2021).

Sauropterygians

New taxa

Research

* A study on the anatomy and replacement pattern of teeth in ''

Henodus ''Henodus'' (from , 'one' and , 'tooth') is an extinct placodont of the Late Triassic period during the early Carnian age. Fossils of ''Henodus chelyops'' were found in the Estherienschichten Member of the Grabfeld Formation, near Tübingen, ...

chelyops'' is published by Pommery ''et al.'' (2021). * A large teeth-bearing dentary of an

eosauropterygia Sauropterygia ("lizard flippers") is an extinct taxon of diverse, aquatic diapsid reptiles that developed from terrestrial ancestors soon after the end-Permian extinction and flourished during the Triassic before all except for the Plesiosau ...

n of uncertain phylogenetic placement, probably related to the enigmatic '' Lamprosauroides goepperti'', is described from the Lower

Muschelkalk The Muschelkalk (German for "shell-bearing limestone"; ) is a sequence of sedimentary rock, sedimentary rock strata (a lithostratigraphy, lithostratigraphic unit) in the geology of central and western Europe. It has a Middle Triassic (240 to 230 m ...

(

Anisian In the geologic timescale, the Anisian is the lower stage (stratigraphy), stage or earliest geologic age, age of the Middle Triassic series (stratigraphy), series or geologic epoch, epoch and lasted from million years ago until million years ag ...

, Middle Triassic) of Winterswijk (

Netherlands , Terminology of the Low Countries, informally Holland, is a country in Northwestern Europe, with Caribbean Netherlands, overseas territories in the Caribbean. It is the largest of the four constituent countries of the Kingdom of the Nether ...

) by Spiekman & Klein (2021). * A study on the bone

histology Histology, also known as microscopic anatomy or microanatomy, is the branch of biology that studies the microscopic anatomy of biological tissue (biology), tissues. Histology is the microscopic counterpart to gross anatomy, which looks at large ...

and possible affinities of '' Proneusticosaurus silesiacus'' is published by Klein & Surmik (2021). * Description of a new specimen of '' Panzhousaurus rotundirostris'' from the

Guanling Formation The Guanling Formation is a Middle Triassic (Anisian or Pelsonian in the regional chronostratigraphy) geologic Formation (geology), formation in southwestern China. Geology The formation encompasses two members. The first member is primarily c ...

(Guizhou, China), providing new information on the anatomy of this reptile, and a study on the phylogenetic relationships of this species is published by Lin ''et al.'' (2021). * New specimen of '' Diandongosaurus'', belonging or related to the species ''D. acutidentatus'' (though approximately three times larger than the

of that species) and lacking most of the right hindlimb, is described from the

(China) by Liu ''et al.'' (2021), who interpret the right hindlimb of this specimen as likely amputated in an attack by an unknown hunter. * The remains of an indeterminate plesiosaur are reported from the

Hauterivian The Hauterivian is, in the geologic timescale, an age in the Early Cretaceous Epoch or a stage in the Lower Cretaceous Series. It spans the time between 132.6 ± 2 Ma and 125.77 (million years ago). The Hauterivian is preceded by the Valangi ...

Katterfeld Formation (

Chile Chile, officially the Republic of Chile, is a country in western South America. It is the southernmost country in the world and the closest to Antarctica, stretching along a narrow strip of land between the Andes, Andes Mountains and the Paci ...

) by Poblete-Huanca ''et al.'' (2021), representing the first record of a Lower Cretaceous plesiosaur from Chile. * A tooth crown of a

pliosaurid Pliosauridae is a family of plesiosaurian marine reptiles from the Latest Triassic to the early Late Cretaceous (Rhaetian to Turonian stages). The family is more inclusive than the archetypal short-necked large headed species that are placed in ...

belonging to the subfamily

Brachaucheninae Pliosauridae is a family (biology), family of plesiosaurian marine reptiles from the Late Triassic, Latest Triassic to the early Late Cretaceous (Rhaetian to Turonian stages). The family is more inclusive than the archetypal short-necked large he ...

is described from the

La Luna Formation (

Venezuela Venezuela, officially the Bolivarian Republic of Venezuela, is a country on the northern coast of South America, consisting of a continental landmass and many Federal Dependencies of Venezuela, islands and islets in the Caribbean Sea. It com ...

) by Bastiaans ''et al.'' (2021), representing the most recent record of a pliosaurid from South America reported to date. * A study aiming to reconstruct the musculature of limbs of ''

Cryptoclidus ''Cryptoclidus'' ( ) is a genus of plesiosaur reptile from the Middle Jurassic Period (geology), period of England, France, and Cuba. Discovery ''Cryptoclidus'' was a plesiosaur whose specimens include adult and juvenile skeletons, and rema ...

eurymerus'' is published by Krahl & Witzel (2021). * A study on the postcranial materials of xenopsarian plesiosaurs from the

Eromanga Basin The Eromanga Basin is a large Mesozoic sedimentary basin in central and northern Australia. It covers parts of Queensland, the Northern Territory, South Australia, and New South Wales, and is a major component of the Great Artesian Basin. The Er ...

(

), aiming to determine the utility of vertebral analysis for differentiating and/or grouping Australian plesiosaur specimens, is published by Vakil, Webb & Cook (2021). * Marx ''et al.'' (2021) describe a new specimen of ''

Cardiocorax ''Cardiocorax'' is an extinct genus of elasmosaurid known from the Late Cretaceous (early Maastrichtian stage) Mocuio Formation of Namibe Province, southern Angola. It contains a single species, ''Cardiocorax mukulu''. Discovery ''Cardiocor ...

mukulu'' from the Maastrichtian Mocuio Formation (

Angola Angola, officially the Republic of Angola, is a country on the west-Central Africa, central coast of Southern Africa. It is the second-largest Portuguese-speaking world, Portuguese-speaking (Lusophone) country in both total area and List of c ...

), including the most complete plesiosaur skull from sub-Saharan Africa reported to date, and evaluate the implications of this specimen for the knowledge of the anatomy and phylogenetic relationships of this plesiosaur. * Redescription of the anatomy of the skull of ''

Thalassomedon ''Thalassomedon'' (from Greek, ''thalassa'', "sea" and Greek, ''medon'', "lord" or "ruler", meaning "sea lord") is a genus of plesiosaur, named by Welles in 1943. Description ''Thalassomedon'' is among the largest elasmosaurids, with the holo ...

haningtoni'', and a study on the phylogenetic relationships of this species, is published by Sachs ''et al.'' (2021). * Description of one of the earliest quarried elasmosaurid specimens from the

–Maastrichtian strata of

Antarctica Antarctica () is Earth's southernmost and least-populated continent. Situated almost entirely south of the Antarctic Circle and surrounded by the Southern Ocean (also known as the Antarctic Ocean), it contains the geographic South Pole. ...

, identified as a non- aristonectine elasmosaurid belonging to the group

Weddellonectia Elasmosauridae, often called elasmosaurs or elasmosaurids, is an extinct family (biology), family of plesiosaurs that lived from the Hauterivian Stage (stratigraphy), stage of the Early Cretaceous to the Maastrichtian stage of the Late Cretaceou ...

, and a study on the evolution of dorsal vertebral count in members of Weddellonectia, is published by O’Gorman, Aspromonte & Reguero (2021). * New information of the skeletal anatomy of '' Alexandronectes zealandiensis'' is provided by O'Gorman ''et al.'' (2021). * The most complete specimen of ''

Kawanectes ''Kawanectes'' (meaning "Kawas swimmer") is a genus of elasmosauridae, elasmosaurid plesiosaur, a type of long-necked marine reptile, that lived in the marginal marine (probably estuary, estuarine) environment of Late Cretaceous Patagonia. It co ...

lafquenianum'' reported to date, providing new information on the anatomy of this plesiosaur, is described by O’Gorman (2021). * Talevi ''et al.'' (2021) describe a pathological cervical vertebra of a plesiosaur from the

Argentina Argentina, officially the Argentine Republic, is a country in the southern half of South America. It covers an area of , making it the List of South American countries by area, second-largest country in South America after Brazil, the fourt ...

, and interpret this finding as the first record of tuberculosis-like infection in a plesiosaur reported to date.

Turtles

New taxa

Research

* A study on the evolution of the organization and composition of the turtle shell is published by Cordero & Vlachos (2021). * A study on turtle forelimb

morphometrics Morphometrics (from Greek μορΦή ''morphe'', "shape, form", and -μετρία ''metria'', "measurement") or morphometry refers to the quantitative analysis of ''form'', a concept that encompasses size and shape. Morphometric analyses are co ...

, their relationship to habitat type, and their implications for the knowledge of habitat preferences of fossil turtles, is published by Dudgeon ''et al.'' (2021). * A study on the morphology of the skeleton of ''

Chinlechelys ''Chinlechelys'' ( meaning ''Chinle turtle'') is an extinct genus of stem-turtle belonging to Testudinata. It lived in the Norian age of the Late Triassic and is the oldest turtle known from North America. Among turtles it is unique, mostly becau ...

tenertesta'', and on its implications for the knowledge of the origin of turtles, is published by Lichtig &

Lucas Lucas or LUCAS may refer to: People * Lucas (surname) * Lucas (given name) Arts and entertainment * Luca Family Singers, or the Lucas, a 19th-century African-American singing group * Lucas, a 1960s Swedish pop group formed by Janne Lucas Perss ...

(2021), who reject the interpretation of ''

Eunotosaurus ''Eunotosaurus'' (''Latin (language), Latin'': Stout-backed lizard) is an extinct genus of amniote, possibly a close relative of turtles. ''Eunotosaurus'' lived in the late Middle Permian (Capitanian stage) and fossils can be found in the Karoo ...

africanus'' and ''

Pappochelys ''Pappochelys'' ( meaning "grandfather turtle" in Greek) is an extinct genus of diapsid reptile possibly related to turtles. The genus contains only one species, ''Pappochelys rosinae'', from the Middle Triassic of Germany, which was named by pal ...

rosinae'' as

stem Stem or STEM most commonly refers to: * Plant stem, a structural axis of a vascular plant * Stem group * Science, technology, engineering, and mathematics Stem or STEM can also refer to: Language and writing * Word stem, part of a word respon ...

-turtles. * A study on the

of the

carapace A carapace is a dorsal (upper) section of the exoskeleton or shell in a number of animal groups, including arthropods, such as crustaceans and arachnids, as well as vertebrates, such as turtles and tortoises. In turtles and tortoises, the unde ...

and limb bones of ''

Araripemys ''Araripemys'' is an extinct marine turtle genus from 112 to 109 million years ago, in the Early Cretaceous Crato and Romualdo Formations of the Araripe Basin in northeastern Brazil Brazil, officially the Federative Republic of Brazil, ...

barretoi'', and on the relation between shell microstructure and lifestyle of this turtle, is published by Sena ''et al.'' (2021). * Revision of the Cretaceous bothremydid ''"

Polysternon ''Polysternon'' is a genus of turtles in the extinct family Bothremydidae. It was described by Portis in 1882, and contains the species ''P. provinciale'' (originally placed in the genus '' Pleurosternon''), which existed during the Cretaceous o ...

" atlanticum'' is published by Pérez-García, Ortega & Murelaga (2021), who consider this taxon to be the senior synonym of '' Iberoccitanemys convenarum'', resulting in a new combination ''Iberoccitanemys atlanticum''. * Reconstruction of the skull and neuroanatomical structures of '' Tartaruscola teodorii'' is presented by Martín-Jiménez & Pérez-García (2021). * New fossil material of ''

Stupendemys ''Stupendemys'' is an extinct genus of freshwater side-necked turtle, belonging to the family Podocnemididae. It is the largest freshwater turtle known to have existed, with a carapace over 2 meters long. Its fossils have been found in northern ...

geographica'' and ''

Caninemys ''Caninemys'' is an extinct genus of large freshwater Pleurodira, side-necked turtle, belonging to the family Podocnemididae. Its fossils have been found in Brazil and Colombia, in rocks dating back from the middle to late Miocene. Discovery an ...

tridentata'' is described from the Miocene

La Victoria Formation The Honda Group (, Tsh, Ngh) is a geological group of the Upper and Middle Magdalena Basins and the adjacent Central and Eastern Ranges of the Colombian Andes. The group, in older literature also defined as formation, is in its present-day ty ...

(

Colombia Colombia, officially the Republic of Colombia, is a country primarily located in South America with Insular region of Colombia, insular regions in North America. The Colombian mainland is bordered by the Caribbean Sea to the north, Venezuel ...

) by Cadena ''et al.'' (2021), who reestablish the validity of ''C. tridentata'' as a taxon distinct from ''S. geographica'', and evaluate the implications of the studied fossils for the knowledge of the changes in the shell and scutes during the

ontogeny Ontogeny (also ontogenesis) is the origination and development of an organism (both physical and psychological, e.g., moral development), usually from the time of fertilization of the ovum, egg to adult. The term can also be used to refer to t ...

in ''S. geographica''. * Redescription and a study on the phylogenetic relationships of ''

Uluops ''Uluops'' is an extinct genus of paracryptodire turtle from the Late Jurassic (Tithonian) of North America. The type and only species is ''Uluops uluops'', which is known from a single skull from the Morrison Formation The Morrison Formation ...

uluops'' is published by Rollot, Evers & Joyce (2021). * Redescription of the anatomy of the skull of '' Arundelemys dardeni'' is published by Evers, Rollot & Joyce (2021). * A study on the morphological variability in the shell of ''

Pleurosternon ''Pleurosternon'' is an extinct genus of freshwater pleurosternid turtle from the latest Jurassic to earliest Cretaceous of Europe. Its type species, ''P. bullockii'' was described by the paleontologist Richard Owen (noted for coining the word ...

bullockii'' is published by Guerrero & Pérez-García (2021). * A study on the ontogenetic development of ''Pleurosternon bullockii'', based on data from small specimens from the

Berriasian In the geological timescale, the Berriasian is an age/ stage of the Early/Lower Cretaceous. It is the oldest subdivision in the entire Cretaceous. It has been taken to span the time between 143.1 ±0.6 Ma and 137.05 ± 0.2 (million years ago) ...

Purbeck Limestone Group The Purbeck Group is an Upper Jurassic to Lower Cretaceous lithostratigraphic group (a sequence of rock strata) in south-east England. The name is derived from the district known as the Isle of Purbeck in Dorset where the strata are exposed in th ...

(

United Kingdom The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Northwestern Europe, off the coast of European mainland, the continental mainland. It comprises England, Scotlan ...

), is published by Guerrero & Pérez-García (2021). * New fossil material of ''

Plesiochelys ''Plesiochelys'' ("near turtle") is a genus of late Jurassic European and Asian turtle. The type species is ''Plesiochelys etalloni''. Fossil records have discovered ''Plesiochelys bigleri'' and ''Plesiochelys etalloni'' from the Kimmeridge Clay ...

'' is described from the Upper Jurassic (

Tithonian In the geological timescale, the Tithonian is the latest age (geology), age of the Late Jurassic Epoch and the uppermost stage (stratigraphy), stage of the Upper Jurassic Series. It spans the time between 149.2 ±0.7 annum, Ma and 143.1 ±0.6 (mi ...

) of the Lusitanian Basin (

) by Pérez-García & Ortega (2021), who also revise the Oxfordian species ''"Hispaniachelys" prebetica'' and transfer it to the genus ''Plesiochelys'', making it the oldest representative of this genus reported to date. * Two specimens of

thalassochelydia Thalassochelydia is a clade of extinct marine turtles from the Late Jurassic and earliest Cretaceous of Europe and South America. The group is defined as including '' Eurysternum'', ''Plesiochelys'' and '' Thalassemys'' to the exclusion of '' Pel ...

n turtles, including a partial hindlimb with well-preserved remains of skin and a large, articulated skeleton of ''

Thalassemys ''Thalassemys'' is a genus of extinct thalassochelydian turtle from the Late Jurassic of western and central Europe. While the genus was originally named by Rütimeyer in 1859 for a large carapace and other associated fragments from the late Kim ...

bruntrutana'', documenting the presence of particularly elongate forelimbs in this turtle, are described from the Upper Jurassic of

Germany Germany, officially the Federal Republic of Germany, is a country in Central Europe. It lies between the Baltic Sea and the North Sea to the north and the Alps to the south. Its sixteen States of Germany, constituent states have a total popu ...

by Joyce, Mäuser & Evers (2021), who interpret these specimens as providing evidence of presence of highly keratinized and partially stiffened flippers in some Late Jurassic turtles, structurally similar to those of extant

sea turtle Sea turtles (superfamily Chelonioidea), sometimes called marine turtles, are reptiles of the order Testudines and of the suborder Cryptodira. The seven existing species of sea turtles are the flatback, green, hawksbill, leatherback, loggerh ...

s. * A study on the skeletal anatomy of ''

Manchurochelys ''Manchurochelys'' is an extinct genus of turtle. It existed during the early Cretaceous of what is now northeast China. It has been found in the Jianshangou Bed of West Liaoning's Yixian Formation. However, it is a rarely found fossil. ''Manchu ...

manchoukuoensis'', based on data from a new specimens from the Lower Cretaceous

Yixian Formation The Yixian Formation (; formerly Romanization of Chinese, transcribed as Yihsien Formation or Yixiang Formation) is a geological formation in Jinzhou, Liaoning, People's Republic of China, that spans the Barremian stage of the Early Cretaceous. I ...

(China), is published by Li, Zhou & Rabi (2021). * A large, thick-shelled turtle egg, preserving an embryo of a

nanhsiungchelyid Nanhsiungchelyidae is an extinct family of land turtles known from Cretaceous deposits in Asia and North America. Nanhsiungchelyids were more terrestrial than many of their contemporaries, and may have gone extinct at the K–Pg event, end of the ...

possibly belonging to the species '' Yuchelys nanyangensis'', is described from the Upper Cretaceous Xiaguan Formation (China) by Ke ''et al.'' (2021). * An upper Miocene to lower Pliocene carettochelyid fossil, representing the southernmost record of this group reported to date, is described from Beaumaris (Victoria,

) by Rule ''et al.'' (2021), who interpret this finding and a discontinuous record of soft-shell turtles in the Cenozoic of Queensland as evidence of at least two colonizations of Australia by

Trionychia Trionychia is a superfamily of turtles which encompasses the species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typic ...

, pre-dating the extant

pig-nosed turtle The pig-nosed turtle (''Carettochelys insculpta''), also known as the Fly River turtle, the pitted-shelled turtle, and the Warrajan is a species of turtle which is native to northern Australia and southern New Guinea. It is the only living mem ...

. * Georgalis (2021) describes a large costal of a soft-shelled turtle from the

Eocene The Eocene ( ) is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (Ma). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene'' comes ...

Mali Mali, officially the Republic of Mali, is a landlocked country in West Africa. It is the List of African countries by area, eighth-largest country in Africa, with an area of over . The country is bordered to the north by Algeria, to the east b ...

, representing the first record of pan-

trionychid Trionychidae is a family of turtles, commonly known as softshell turtles or simply softshells. The family was described by Leopold Fitzinger in 1826. Softshells include some of the world's largest freshwater turtles, though many can adapt to liv ...

turtles from the

Paleogene The Paleogene Period ( ; also spelled Palaeogene or Palæogene) is a geologic period and system that spans 43 million years from the end of the Cretaceous Period Ma (million years ago) to the beginning of the Neogene Period Ma. It is the fir ...

of Africa reported to date. * New specimens of the

tortoise Tortoises ( ) are reptiles of the family Testudinidae of the order Testudines (Latin for "tortoise"). Like other turtles, tortoises have a shell to protect from predation and other threats. The shell in tortoises is generally hard, and like o ...

s '' Hadrianus majusculus'' and ''H. corsoni'' and geoemydids '' Echmatemys haydeni'' and ''E. naomi'', including skull and juvenile material, and providing new information on the morphology, intraspecific variation and ontogeny of these turtles, are described from the

Willwood Formation The Willwood Formation is a sedimentary sequence deposited during the late Paleocene to early Eocene, or Clarkforkian, Wasatchian and Bridgerian in the NALMA classification.Green River Formation The Green River Formation is an Eocene geologic formation that records the sedimentation in a group of intermountain lakes in three basins along the present-day Green River (Colorado River), Green River in Colorado, Wyoming, and Utah. The sedimen ...

(

Wyoming Wyoming ( ) is a landlocked U.S. state, state in the Mountain states, Mountain West subregion of the Western United States, Western United States. It borders Montana to the north and northwest, South Dakota and Nebraska to the east, Idaho t ...

United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

) by Lichtig, Lucas & Jasinski (2021). * A study on the phylogenetic relationships of Eocene geoemydids ''"Ocadia" kehreri'' and ''"Ocadia" messeliana'' from the

Messel pit The Messel Formation is a Formation (geology), geologic formation in Hesse, central Germany, dating back to the Eocene Epoch (geology), epoch (about 47 Ma). Its geographic range is restricted to the Messel pit. There it unconformably overlie ...

(

) is published by Ascarrunz, Claude & Joyce (2021). * Description of new fossil material of '' Bridgeremys pusilla'' from the

Uinta Formation The Uinta Formation is a geologic formation in northeastern Utah Utah is a landlocked state in the Mountain states, Mountain West subregion of the Western United States. It is one of the Four Corners states, sharing a border with Ariz ...

(

Utah Utah is a landlocked state in the Mountain states, Mountain West subregion of the Western United States. It is one of the Four Corners states, sharing a border with Arizona, Colorado, and New Mexico. It also borders Wyoming to the northea ...

, United States), and a study on the differences in morphology of the shell and likely ecology of ''B. pusilla'' and two coeval species of '' Echmatemys'', is published by Adrian ''et al.'' (2021). * A study on the phylogenetic relationships and evolutionary history of the tortoise ''

Chelonoidis alburyorum ''Chelonoidis'' is a genus of turtles in the tortoise family erected by Leopold Fitzinger in 1835. They are found in South America and the Galápagos Islands, and formerly had a wide distribution in the West Indies. The multiple subspecies of t ...

'' from

The Bahamas The Bahamas, officially the Commonwealth of The Bahamas, is an Archipelagic state, archipelagic and island country within the Lucayan Archipelago of the Atlantic Ocean. It contains 97 per cent of the archipelago's land area and 88 per cent of ...

, based on data from nearly complete mitochondrial genomes, is published by Kehlmaier ''et al.'' (2021). * A study on the identity of the type material of '' Centrochelys atlantica'', based on data from ancient DNA, is published by Kehlmaier ''et al.'' (2021), who identify this material as belonging to a specimen of the

red-footed tortoise The red-footed tortoise (''Chelonoidis carbonarius'') is a species of tortoise from northern South America. These medium-sized tortoises generally average as adults, but can reach over . They have dark-colored (nearly black), “loaf”-shaped ...

, leaving the Quaternary tortoise known from fossils excavated on the

Sal Island Sal (Portuguese for "salt") is an island in Cape Verde. Sal is a tourist destination with white sandy beaches and over 350 days of sunshine a year. It is one of the three sandy eastern islands of the Cape Verde archipelago in the central Atlantic ...

in the 1930s without a scientific name. * A well-preserved

humerus The humerus (; : humeri) is a long bone in the arm that runs from the shoulder to the elbow. It connects the scapula and the two bones of the lower arm, the radius (bone), radius and ulna, and consists of three sections. The humeral upper extrem ...

a of giant turtle, representing the first known record of gigantic

Mesozoic The Mesozoic Era is the Era (geology), era of Earth's Geologic time scale, geological history, lasting from about , comprising the Triassic, Jurassic and Cretaceous Period (geology), Periods. It is characterized by the dominance of archosaurian r ...

sea turtles in Africa, is described from the

Dakhla Formation The Dakhla Formation, also called the Dakhla Shale, is a Maastrichtian-Danian geologic formation in the Western Desert, Egypt. Dinosaur remains are among the fossils that have been recovered from the formation, although none have yet been referr ...

(

Egypt Egypt ( , ), officially the Arab Republic of Egypt, is a country spanning the Northeast Africa, northeast corner of Africa and Western Asia, southwest corner of Asia via the Sinai Peninsula. It is bordered by the Mediterranean Sea to northe ...

) by Abu El-Kheir, AbdelGawad & Kassab (2021). * New specimen of ''

Euclastes ''Euclastes'' is an extinct genus of sea turtles that survived the Cretaceous–Paleogene mass extinction. The genus was first named by Edward Drinker Cope in 1867, and contains three species. ''E. hutchisoni'', was named in 2003 but has since b ...

wielandi'' is described from the Paleocene (

Danian The Danian is the oldest age or lowest stage of the Paleocene Epoch or Series, of the Paleogene Period or System, and of the Cenozoic Era or Erathem. The beginning of the Danian (and the end of the preceding Maastrichtian) is at the Cretac ...

)

Hornerstown Formation The Hornerstown Formation is a latest Cretaceous to early Paleocene-aged geologic Formation (geology), formation in New Jersey. It preserves a variety of fossil remains, including those of dinosaurs, and contains direct evidence of the Mass morta ...

(

New Jersey New Jersey is a U.S. state, state located in both the Mid-Atlantic States, Mid-Atlantic and Northeastern United States, Northeastern regions of the United States. Located at the geographic hub of the urban area, heavily urbanized Northeas ...

, United States) by Ullmann & Carr (2021), who interpret this specimen as proving that ''E. wielandi'' is a

senior synonym In taxonomy, the scientific classification of living organisms, a synonym is an alternative scientific name for the accepted scientific name of a taxon. The botanical and zoological codes of nomenclature treat the concept of synonymy differently. ...

of ''Catapleura repanda'', and study the phylogenetic relationships of ''E. wielandi''. * A hard-shelled sea turtle specimen, preserved with vestigial soft tissues and likely with incompletely healed bite marks inflicted by a crocodylian or another large-sized seagoing tetrapod, is described from the Eocene (

Ypresian In the geologic timescale the Ypresian is the oldest age (geology), age or lowest stage (stratigraphy), stratigraphic stage of the Eocene. It spans the time between , is preceded by the Thanetian Age (part of the Paleocene) and is followed by th ...

)

Fur Formation The Fur Formation is a marine geological formation of Ypresian ( Lower Eocene Epoch, c. 56.0-54.5 Ma) age which crops out in the Limfjord region of northern Denmark from Silstrup via Mors and Fur to Ertebølle, and can be seen in many cliffs and ...

(

Denmark Denmark is a Nordic countries, Nordic country in Northern Europe. It is the metropole and most populous constituent of the Kingdom of Denmark,, . also known as the Danish Realm, a constitutionally unitary state that includes the Autonomous a ...

) by De La Garza ''et al.'' (2021).

Archosauriformes

Archosaurs

Other archosauriforms

New taxa

Research

* A study on the femoral shape variation and on the relationship between femoral morphology and locomotor habits in early archosaurs and non-archosaur archosauriforms is published by Pintore ''et al.'' (2021). * Fossil material of a member of the genus ''

Doswellia ''Doswellia'' is an extinct genus of archosauriform from the Late Triassic of North America. It is the most notable member of the family Doswelliidae, related to the Proterochampsidae, proterochampsids. ''Doswellia'' was a low and heavily built c ...

'' belonging or related to the species ''D. kaltenbachi'' is described from the Upper Triassic

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 ...

(

Arizona Arizona is a U.S. state, state in the Southwestern United States, Southwestern region of the United States, sharing the Four Corners region of the western United States with Colorado, New Mexico, and Utah. It also borders Nevada to the nort ...

, United States) by Parker ''et al.'' (2021), who interpret this finding as evidence of biogeographic links between the vertebrate assemblage from the Chinle Formation and other Late Triassic assemblages from

Texas Texas ( , ; or ) is the most populous U.S. state, state in the South Central United States, South Central region of the United States. It borders Louisiana to the east, Arkansas to the northeast, Oklahoma to the north, New Mexico to the we ...

and

Virginia Virginia, officially the Commonwealth of Virginia, is a U.S. state, state in the Southeastern United States, Southeastern and Mid-Atlantic (United States), Mid-Atlantic regions of the United States between the East Coast of the United States ...

. * A study on bone

proterochampsid Proterochampsidae is a family of proterochampsian archosauriforms. Proterochampsids may have filled an ecological niche similar to modern crocodiles, and had a general crocodile-like appearance. They lived in what is now South America in the Mid ...

specimens from the Triassic

Chañares Formation The Chañares Formation is a Carnian-age geologic formation of the Ischigualasto-Villa Unión Basin, located in La Rioja Province, Argentina. It is characterized by drab-colored fine-grained volcaniclastic claystones, siltstones, and sandstones ...

(Argentina), aiming to infer history traits related to growth dynamics,

ontogenetic Ontogeny (also ontogenesis) is the origination and development of an organism (both physical and psychological, e.g., moral development), usually from the time of fertilization of the egg to adult. The term can also be used to refer to the stu ...

changes, dermal armor

histogenesis Histogenesis is the formation of different tissues from undifferentiated cells. These cells are constituents of three primary germ layers, the endoderm, mesoderm, and ectoderm. The science of the microscopic structures of the tissues formed within ...

and lifestyle, is published by Ponce ''et al.'' (2021). * A large

phytosaur Phytosaurs (Φυτόσαυροι in Greek, meaning 'plant lizard') are an extinct group of large, mostly semiaquatic Late Triassic archosauriform or basal archosaurian reptiles. Phytosaurs belong to the order Phytosauria and are sometimes ref ...

specimen likely belonging to the species '' Smilosuchus gregorii'', preserved with evidence of pathologies evoking aspects of both

osteomyelitis Osteomyelitis (OM) is the infectious inflammation of bone marrow. Symptoms may include pain in a specific bone with overlying redness, fever, and weakness. The feet, spine, and hips are the most commonly involved bones in adults. The cause is ...

and hypertrophic osteopathy, is described from

Norian The Norian is a division of the Triassic geological period, Period. It has the rank of an age (geology), age (geochronology) or stage (stratigraphy), stage (chronostratigraphy). It lasted from ~227.3 to Mya (unit), million years ago. It was prec ...

strata near St. Johns (

, United States) by Heckert, Viner & Carrano (2021). * A study on the enamel microstructure of phytosaur teeth from western and eastern North American localities, evaluating their implications for the knowledge of

biogeographic 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, ...

distributions and ecology of phytosaurs, is published by Hoffman, Miller-Camp & Heckert (2021).

Other reptiles

New taxa

Research

* Revision of putative

Carboniferous The Carboniferous ( ) is a Geologic time scale, geologic period and System (stratigraphy), system of the Paleozoic era (geology), era that spans 60 million years, from the end of the Devonian Period Ma (million years ago) to the beginning of the ...

reptile tracks, evaluating their implications for the knowledge of the evolution of locomotor capabilities of putative trackmakers and of the biogeography of the earliest reptiles, is published by Marchetti ''et al.'' (2021), who interpret '' Hylopus hardingi'' as tracks probably produced by anamniote

reptiliomorphs Reptiliomorpha (meaning reptile-shaped; in PhyloCode known as ''Pan-Amniota'') is a clade containing the amniotes and those tetrapods that share a more recent common ancestor with amniotes than with living amphibians (lissamphibians). It was defi ...

. * Footprints of early reptiles, including footprints representing the ichnotaxon '' Notalacerta missouriensis'' and footprints possibly belonging to the ichnogenus ''Notalacerta'', are described from the

Meisenheim Meisenheim () is a town in the Bad Kreuznach (district), Bad Kreuznach Districts of Germany, district in Rhineland-Palatinate, Germany. It belongs to the Meisenheim (Verbandsgemeinde), like-named ''Verbandsgemeinde'', and is also its seat. Meise ...

, Tambach, Sulzbach and

Standenbühl Standenbühl is a municipality in the Donnersbergkreis district, in Rhineland-Palatinate, Germany Germany, officially the Federal Republic of Germany, is a country in Central Europe. It lies between the Baltic Sea and the North Sea to the n ...

formations (

Pennsylvanian Pennsylvanian may refer to: * A person or thing from Pennsylvania * Pennsylvanian (geology) The Pennsylvanian ( , also known as Upper Carboniferous or Late Carboniferous) is, on the International Commission on Stratigraphy, ICS geologic timesc ...

and

Cisuralian The Cisuralian, also known as the Early Permian, is the first series/epoch of the Permian. The Cisuralian was preceded by the Pennsylvanian and followed by the Guadalupian. The Cisuralian Epoch is named after the western slopes of the Ural Mou ...

) by Marchetti ''et al.'' (2021), potentially extending the European record of the ichnogenus ''Notalacerta'' back to the

Moscovian Moscovian may refer to: *An inhabitant of Moscow, the capital of Russia *Something of, from, or related to Moscow *Moscovian (Carboniferous) The Moscovian is in the International Commission on Stratigraphy, ICS geologic timescale a stage (strat ...

. * Revision of diagnostic characters used to identify

mesosaur Mesosaurs ("middle lizards") were a group of small aquatic reptiles that lived during the early Permian period ( Cisuralian), roughly 299 to 270 million years ago. Mesosaurs were the first known aquatic reptiles, having apparently returned to a ...

species is published by Piñeiro ''et al.'' (2021), who report that they could not find unambiguous

autapomorphies In phylogenetics, an autapomorphy is a distinctive feature, known as a derived trait, that is unique to a given taxon. That is, it is found only in one taxon, but not found in any others or outgroup taxa, not even those most closely related to ...

that characterized '' Brazilosaurus'' or ''

Stereosternum ''Stereosternum tumidum'' (meaning "rigid chest") (Stereos, Greek: “solid, firm”; Sternon, Greek: “chest, breastbone”) is an extinct genus of mesosaur marine reptile from the Early Permian of Brazil and also the Great Karoo Basin of South ...

''. * Redescription of the

and description of the second known specimen of ''

Eudibamus ''Eudibamus'' is an extinct genus of biped bolosaurid reptile known from the Free State of Thuringia of central Germany. It had a very small size reaching only 25-26 cm in length. Discovery ''Eudibamus'' is known only from the holotype MN ...

cursoris'', providing new information on the skeletal anatomy and locomotor abilities of this reptile, is published by Berman ''et al.'' (2021). * A study on the anatomy of the skull of ''

Nochelesaurus ''Embrithosaurus'' was a pareiasaur from the Permian of South Africa. Description ''Embrithosaurus'' was in length and in weight. The skull is relatively deep and narrow. The body is lightly armoured with thin, smooth dermal scutes. Species * ...

alexanderi'' is published by Van den Brandt ''et al.'' (2021). * A study on the anatomy of the postcranial skeletons of ''

Bradysaurus ''Bradysaurus'' is a genus of large, primitive and widespread pareiasaur. They possessed a covering of armoured scutes, likely serving as defense against their main predators, the gorgonopsians. Fossils of ''Bradysaurus'' are known from the ''T ...

baini'', ''

Embrithosaurus ''Embrithosaurus'' was a pareiasaur from the Permian of South Africa. Description ''Embrithosaurus'' was in length and in weight. The skull is relatively deep and narrow. The body is lightly armoured with thin, smooth dermal scutes. Species * ...

schwarzi'' and ''Nochelesaurus alexanderi'' is published by van den Brandt ''et al.'' (2021). * A study on the skeletal anatomy and phylogenetic relationships of ''

Provelosaurus ''Provelosaurus'' is an extinct Pareiasaur genus of the Late Permian found on the road between Aceguá and Bagé in the Paleorrota, Rio Grande do Sul, Brazil. Found in the Rio do Rasto Formation, aged about 260 million years.http://www.ufrgs.br ...

americanus'', based on data from new fossils and a review of the previously described material, is published by Cisneros, Dentzien-Dias & Francischini (2021). * Romano ''et al.'' (2021) provide a body mass estimate of ''

Scutosaurus ''Scutosaurus'' ("shield lizard") is an extinct genus of pareiasaur parareptiles. Its genus name refers to large plates of armor scattered across its body. It was a large anapsid reptile that, unlike most reptiles, held its legs underneath its b ...

karpinskii''. *

Tetrapod A tetrapod (; from Ancient Greek :wiktionary:τετρα-#Ancient Greek, τετρα- ''(tetra-)'' 'four' and :wiktionary:πούς#Ancient Greek, πούς ''(poús)'' 'foot') is any four-Limb (anatomy), limbed vertebrate animal of the clade Tetr ...

footprints assigned to 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. ''Ichnotaxon'' comes from the Ancient Greek (''íchnos'') meaning "track" and English , itself derived from ...

'' Hyloidichnus'', produced by

captorhinids Captorhinidae 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 Captorhinids are a clade of sm ...

or similar reptiles and providing new information on the locomotion of these reptiles, are described from the

Permian The Permian ( ) is a geologic period and System (stratigraphy), 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 251.902 Mya. It is the s ...

Pelitic Formation of Gonfaron (Le Luc Basin, Var,

) by Logghe ''et al.'' (2021). * Description of a new specimen of ''

Anthracodromeus ''Anthracodromeus'' is an extinct genus of Late Carboniferous (late Westphalian (stage), Westphalian stage) "Protorothyrididae, protorothyridid" tetrapods known from Ohio. It is known from the holotype American Museum of Natural History, AMNH&nbs ...

longipes'' from the

Allegheny Group The Allegheny Group, often termed the Allegheny Formation, is a Pennsylvanian (geology), Pennsylvanian-age geological unit in the Appalachian Plateau. It is a major coal-bearing unit in the eastern United States, extending through western and cen ...

(

Ohio Ohio ( ) is a U.S. state, state in the Midwestern United States, Midwestern region of the United States. It borders Lake Erie to the north, Pennsylvania to the east, West Virginia to the southeast, Kentucky to the southwest, Indiana to the ...

, United States), preserving an

ungual An ungual (from Latin ''unguis'', i.e. ''nail'') is a highly modified distal toe bone which ends in a hoof, claw, or nail. Elephants and ungulates have ungual phalanges, as did the sauropod Sauropoda (), whose members are known as sauropods (; ...

-bearing

manus Manus may refer to: Relating to locations around New Guinea *Manus Island, a Papua New Guinean island in the Admiralty Archipelago ** Manus languages, languages spoken on Manus and islands close by ** Manus Regional Processing Centre, an offshore ...

and pedes, and a study on the locomotor ecology of this reptile is published by Mann ''et al.'' (2021). * Partial ilium of a non-archosauromorph

neodiapsid Diapsids ("two arches") are a clade of sauropsids, distinguished from more primitive eureptiles by the presence of two holes, known as temporal fenestrae, in each side of their skulls. The earliest traditionally identified diapsids, the Araeosceli ...

reptile is described from the upper

Panchet Formation The Panchet Formation is an Early Triassic geological formation from the Damodar Valley of India. It is among the few geological formations outside of Russia, South Africa, and China that documents the recovery of global ecosystems immediately ...

(

) by Ezcurra, Bandyopadhyay & Sen (2021), expanding known diversity of

Early Triassic The Early Triassic is the first of three epochs of the Triassic Period of the geologic timescale. It spans the time between 251.9 Ma and Ma (million years ago). Rocks from this epoch are collectively known as the Lower Triassic Series, which ...

reptiles from this formation. * A study on the skeletal anatomy, gliding apparatus and phylogenetic relationships of ''

Weigeltisaurus ''Weigeltisaurus'' is an extinct genus of weigeltisaurid reptile from the Late Permian Kupferschiefer of Germany and Marl Slate of England. It has a single species, originally named as ''Palaechamaeleo jaekeli'' in 1930 and later assigned the na ...

jaekeli'', based on data from a nearly complete skeleton from the Upper Permian

Kupferschiefer The Kupferschiefer (German for Copper Shale, Copper Schist or Copper Slate) or Kupfermergel (Copper Marl), (T1 or Z1) is an extensive and remarkable sedimentary unit in Central Europe. The relatively monotonous succession is typically and maximu ...

(

), is published by Pritchard ''et al.'' (2021). * Redescription of the anatomy of the skull of ''

Coelurosauravus ''Coelurosauravus'' (meaning "hollow-tailed lizard grandfather") is an extinct genus of gliding reptile, known from the Late Permian of Madagascar. Like other members of the family Weigeltisauridae, members of this genus possessed long, rod-like ...

elivensis'' is published by Buffa ''et al.'' (2021). * A study on the anatomy and phylogenetic relationships of '' Paliguana whitei'' is published by Ford ''et al.'' (2021). * A study on the anatomy and phylogenetic relationships of ''

Marmoretta ''Marmoretta'' is an extinct genus of small lepidosauromorph reptile known from the Middle-Late Jurassic of Britain and Portugal. The genus contains two species, ''M. oxoniensis'' and ''M. drescherae''. Discovery and naming ''Marmoretta'' is k ...

oxoniensis'' is published by Griffiths ''et al.'' (2021). * Putative

choristodera Choristodera (from the Greek χωριστός ''chōristos'' + δέρη ''dérē'', 'separated neck') is an extinct order of semiaquatic diapsid reptiles that ranged from the Middle Jurassic, or possibly Triassic, to the Miocene (168 to 20 or p ...

from the

Bathonian In the geologic timescale the Bathonian is an age (geology), age and stage (stratigraphy), stage of the Middle Jurassic. It lasted from approximately 168.2 ±1.2 annum, Ma to around 165.3 ±1.1 Ma (million years ago). The Bathonian Age succeeds ...

Peski locality ( Moskvoretskaya Formation;

Moscow Oblast Moscow Oblast (, , informally known as , ) is a federal subjects of Russia, federal subject of Russia (an oblast). With a population of 8,524,665 (Russian Census (2021), 2021 Census) living in an area of , it is one of the most densely populate ...

Russia Russia, or the Russian Federation, is a country spanning Eastern Europe and North Asia. It is the list of countries and dependencies by area, largest country in the world, and extends across Time in Russia, eleven time zones, sharing Borders ...

) is reinterpreted as a fossil a member of

Lepidosauromorpha Lepidosauromorpha (in PhyloCode known as Pan-Lepidosauria) is a group of reptiles comprising all diapsids closer to lizards than to archosaurs (which include crocodiles and birds). The only living sub-group is the Lepidosauria, which contains tw ...

similar to ''

Fraxinisaura ''Fraxinisaura'' is an extinct genus of basal lepidosauromorph reptile known from the Middle Triassic of Germany. The only known species is ''Fraxinisaura rozynekae''. It possessed an elongated snout, unique features of the teeth, and an ilium ...

'' and ''

'' by Skutschas ''et al.'' (2021), who interpret this specimens as the first known record of basal lepidosauromorphs in the

Middle Jurassic The Middle Jurassic is the second Epoch (geology), epoch of the Jurassic Period (geology), Period. It lasted from about 174.1 to 161.5 million years ago. Fossils of land-dwelling animals, such as dinosaurs, from the Middle Jurassic are relativel ...

of European Russia. * Choristoderan vertebrae, representing the first record of choristoderans from the Upper Cretaceous of Asia reported to date, are described from the

Tamagawa Formation (

) by Matsumoto ''et al.'' (2021). * New fossil material of neochoristoderes, representing the first known record of this group from the Atlantic coastal plain, is described from the latest Cretaceous of the

Navesink Formation The Navesink Formation is a 66 to 70 mya greensand glauconitic marl and sand geological formation in New Jersey. It is known for its Cretaceous period fossil shell beds and dinosaur bones. Description The Navesink Formation, named after Navesin ...

and the

Ellisdale Fossil Site The Ellisdale Fossil Site is located near Ellisdale in the valley of the Crosswicks Creek, in Monmouth County, New Jersey, United States. The site has produced the largest and most diverse fauna of Late Cretaceous terrestrial animals from eas ...

(

, United States) by Dudgeon ''et al.'' (2021), who also attempt to determine possible causes of the apparent rarity of neochoristoderes in

Appalachia Appalachia ( ) is a geographic region located in the Appalachian Mountains#Regions, central and southern sections of the Appalachian Mountains in the east of North America. In the north, its boundaries stretch from the western Catskill Mountai ...

. * A study comparing cervical morphology and neck mobility in ''

Champsosaurus ''Champsosaurus'' is an extinct genus of crocodile-like choristodere reptile, known from the Late Cretaceous and early Paleogene periods of North America and Europe (Campanian–Paleocene). The name ''Champsosaurus'' is thought to come from , () ...

'', ''

Simoedosaurus ''Simoedosaurus'' is an extinct reptile known from the Paleocene of North America, Europe and western Asia, and a member of the Choristodera, a group of aquatic reptiles that lived in the Northern Hemisphere from the Jurassic to the early Cenoz ...

'' and extant

gharial The gharial (''Gavialis gangeticus''), also known as gavial or fish-eating crocodile, is a crocodilian in the family (biology), family Gavialidae and among the longest of all living crocodilians. Mature females are long, and males . Adult males ...

, and evaluating their implications for the knowledge of the feeding behaviour of choristoderans, is published by Matsumoto, Fujiwara &

Evans Evans or Evan's may refer to: People * Evans (surname) * List of people with surname Evans * Evans Welch, Trinidad and Tobago politician Places United States * Evans Island, an island of Alaska * Evans, Colorado * Evans, Georgia * Evans County ...

(2021). * A study on the phylogenetic relationships of

archosauromorph 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) than to lepidosaurs (such as tuataras, lizards, a ...

reptiles, aiming to determine the relationships of "

protorosaurs Protorosauria is an extinct, likely paraphyletic group of basal archosauromorph reptiles from the latest Middle Permian (Capitanian stage) to the end of the Late Triassic (Rhaetian stage) of Asia, Europe and North America. It was named by the E ...

", is published by Spiekman,

Fraser Fraser may refer to: Places Antarctica * Fraser Point, South Orkney Islands Australia * Fraser, Australian Capital Territory, a suburb in the Canberra district of Belconnen * Division of Fraser (Australian Capital Territory), a former federal ...

& Scheyer (2021), who name a new clade

Dinocephalosauridae Trachelosauridae (also known as Dinocephalosauridae) is an extinct clade of archosauromorph reptiles that lived throughout the Triassic period. Like their close relatives the tanystropheids, they were "Protorosauria, protorosaur"-Evolutionary gra ...

. * A study on the evolution of the morphological diversity of late Permian to Late Jurassic archosauromorph reptiles is published by Foth, Sookias & Ezcurra (2021). * A study on the evolution of body size of archosauromorph reptiles during the first 90 million years of their evolutionary history is published by Pradelli, Leardi & Ezcurra (2021). * Revision and a study on the phylogenetic affinities of ''

Malerisaurus ''Malerisaurus'' is an extinct genus of archosauromorph known from Telangana of India and Texas of the USA. Description ''Malerisaurus'' was a medium-sized archosauromorph which averaged 1.2 meters in length. ''Malerisaurus'' is known from the h ...

'' is published by Nesbitt ''et al.'' (2021), who interpret this reptile as an early diverging, but late-surviving, carnivorous member of

Azendohsauridae Azendohsauridae is a family of allokotosaurian archosauromorphs that lived during the Middle to Late Triassic period, around 242-216 million years ago. The family was originally named solely for the eponymous ''Azendohsaurus'', marking out its di ...

. * Revision and a study on the phylogenetic relationships of '' Eifelosaurus triadicus'' is published by Sues, Ezcurra & Schoch (2021). * A study on patterns of neurocentral suture closure in the vertebrae of hyperodapedontine rhynchosaurs during their

, evaluating their implications for the knowledge of the evolution of patterns of neurocentral suture closure in

reptiles and most likely ancestral condition in

archosaur Archosauria () or archosaurs () is a clade of diapsid sauropsid tetrapods, with birds and crocodilians being the only extant taxon, extant representatives. Although broadly classified as reptiles, which traditionally exclude birds, the cladistics ...

s, is published by Heinrich ''et al.'' (2021). * A study on the anatomy of the skull of the

specimen of ''

Hyperodapedon ''Hyperodapedon'' (from , 'above' and , 'pavement') is an extinct genus of rhynchosaur reptiles which lived during Triassic, Late Triassic period. Like other rhynchosaurs, it was an heavily built Archosauromorpha, archosauromorph, distantly rel ...

sanjuanensis'' is published by Gentil &

Ezcurra Ezcurra is a surname. Notable people with the surname include: * Alma Ezcurra (born 1986), Spanish politician * Bautista Ezcurra (born 1995), Argentine rugby union player * Encarnación Ezcurra (1795–1838), Argentine political activist * Exequiel ...

(2021).

Reptiles in general

* A study comparing species richness of synapsids and reptiles during the

and

, evaluating the impact of the preservation biases, of the effect of ''

Lagerstätte A Fossil-Lagerstätte (, from ''Lager'' 'storage, lair' '' Stätte'' 'place'; plural ''Lagerstätten'') is a sedimentary deposit that preserves an exceptionally high amount of palaeontological information. ''Konzentrat-Lagerstätten'' preserv ...

n'', and of contested phylogenetic placement of late Carboniferous and early Permian tetrapods on estimates of relative diversity patterns of synapsids and reptiles, is published by Brocklehurst (2021), who interprets his findings as challenging the assumption that synapsids dominated during the Pennsylvanian and Cisuralian. * A study on the evolution of the feeding apparatus in early

amniote Amniotes are tetrapod vertebrate animals belonging to the clade Amniota, a large group that comprises the vast majority of living terrestrial animal, terrestrial and semiaquatic vertebrates. Amniotes evolution, evolved from amphibious Stem tet ...

s, aiming to quantify variation in evolutionary rates and constraints during early diversification of amniotes, is published by Brocklehurst & Benson (2021). * A study comparing the morphology of the maxillary canal of ''

Heleosaurus ''Heleosaurus scholtzi'' is an extinct species of basal synapsids, known as pelycosaurs, in the family of Varanopidae during the middle Permian.Reisz, R. R. & Modesto, S. P. 2007. ''Heleosaurus scholtzi'' from the Permian of South Africa: a varan ...

scholtzi'', ''

Varanosaurus ''Varanosaurus'' ('monitor lizard') is an extinct genus of early ophiacodontid synapsid that lived during the Artinskian and Kungurian ages of the Permian.R. R. Reisz. 1986. Pelycosauria. ''Handbuch der Paläoherpetologie / Encyclopedia of Pal ...

acutrostris'', ''

Orovenator ''Orovenator'' is an extinct genus of diapsid from Lower Permian ( Artinskian stage) deposits of Oklahoma, United States. It is known from two partial skulls from the Richards Spur locality in Oklahoma. The holotype OMNH 74606 consists o ...

mayorum'' and '' Prolacerta broomi'', and evaluating the implications of the morphology of the maxillary canal for the knowledge of the phylogenetic placement of

varanopids Varanopidae is an extinct family of amniotes known from the Late Carboniferous to Middle Permian that resembled monitor lizards (with the name of the group deriving from the monitor lizard genus ''Varanus'') and may have filled a similar niche. T ...

, is published by Benoit ''et al.'' (2021). * Fischer, Weis & Thuy (2021) describe new ichthyosaur and plesiosaur fossils from successive geological formations in

Belgium Belgium, officially the Kingdom of Belgium, is a country in Northwestern Europe. Situated in a coastal lowland region known as the Low Countries, it is bordered by the Netherlands to the north, Germany to the east, Luxembourg to the southeas ...

and

Luxembourg Luxembourg, officially the Grand Duchy of Luxembourg, is a landlocked country in Western Europe. It is bordered by Belgium to the west and north, Germany to the east, and France on the south. Its capital and most populous city, Luxembour ...

spanning the Lower–Middle Jurassic transition, and evaluate the implications of these fossils for the knowledge of the evolution of marine reptile assemblages across the Early–Middle Jurassic transition. * A study on rates of morphological evolution in the evolutionary history of squamates and rhynchocephalians is published by Herrera-Flores ''et al.'' (2021).

References

{{reflist 2021 in paleontology