2021 in reptile paleontology

This list of fossil reptiles described in 2021 is a list of new taxa of fossil reptiles that were described during the year 2021, as well as other significant discoveries and events related to reptile paleontology that occurred in 2021.

Research

 * A study on the evolution of tooth complexity in squamates, 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 diversity of squamates occurred in the mid-Cretaceous, 110–90 Ma, before the first rise in taxonomic diversity of this group in the Campanian.
 * A study on the dietary preferences of lizards from the Upper Cretaceous Iharkút vertebrate locality (Hungary) 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 mixtecus was bipedal while Tijubina pontei was facultatively bipedal.
 * Augé, Dion & Phélizon (2021) describe the lizard fauna from the Paleocene locality of Montchenot (Paris Basin, France), 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), providing new information on the composition and biogeography 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 (France), including the first records of Ophisaurus holeci and the gallotiine lacertid Janosikia from France, is published by Georgalis & Scheyer (2021).
 * A study on the fossil record of lizards and snakes from the Guadeloupe 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 maxillae of extant New Zealand diplodactylids, and on its implications for the knowledge of the affinities of subfossil 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 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 are described for the first time from the El Hierro island (Canary Islands) by Palacios-García et al. (2021), providing the first evidence of the possible coexistence of two giant fossil species of Gallotia on the same island.
 * Fossil material of a large anguimorph 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) by Cabezuelo Hernández et al. (2021).
 * A study on the anatomy and phylogenetic relationships of Tetrapodophis amplectus is published by Caldwell et al. (2021), who reinterpret this squamate as a dolichosaur.
 * A yaguarasaurine mosasauroid is reported from the Cenomanian-Turonian beds of Coahuila (Mexico) by Jiménez-Huidobro et al. (2021), representing the earliest occurrence of a non-aigialosaur mosasauroid from North America reported to date.
 * Redescription and a study on the geographic provenance of the fossil material of "Liodon" asiaticum is published by Bardet et al. (2021).
 * One to seven month-long life histories of specimens of Platecarpus tympaniticus and Clidastes propython collected from chalk deposits of the Western Interior Seaway and Mississippi Embayment in Kansas and Alabama 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-type mosasaurs in the Northwestern Pacific Ocean reported to date is described from the Campanian Hiraiso Formation and Maastrichtian Isoai Formation (Japan) by Kato et al. (2021).
 * First confirmed non-dental mosasaur remains from the Maastrichtian Breien Member of the Hell Creek Formation (North Dakota, 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 on the evolution and dispersal of snakes, is published by Klein et al. (2021).
 * An assemblage of vertebrae of Palaeophis 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) of Togo by Georgalis et al. (2021).
 * A vertebra of Naja romani is described from the Miocene (Turolian) 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 complex from the early Late Pleistocene of the Qafzeh cave (Israel), 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 Homo sapiens occupations.

Research

 * Description of anatomy of the palate of Chaohusaurus brevifemoralis is published by Yin, Ji & Zhou (2021).
 * A study on the anatomy of the skull of the holotype specimen of Besanosaurus leptorhynchus, description of additional specimens from the Middle Triassic Besano Formation (Italy/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 of B. leptorhynchus.
 * New stenopterygiid ichthyosaur fossils, representing some of the best preserved Toarcian specimens from Europe (including a specimen with possible soft tissue preservation), are described from south-east France 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.
 * A specimen of Ichthyosaurus belonging or related to the species I. communis is identified from the Sinemurian Coimbra Formation (Portugal) 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, and describe a third specimen which is the most complete ichthyosaur from this region of Gondwanaland.
 * A study aiming to determine whether Cretaceous ichthyosaur remains from Australia can be attributed to the species Platypterygius australis on the basis of vertebral data alone is published by Vakil, Webb & Cook (2021).

Research

 * A study on the anatomy and replacement pattern of teeth in Henodus chelyops is published by Pommery et al. (2021).
 * A large teeth-bearing dentary of an eosauropterygian of uncertain phylogenetic placement, probably related to the enigmatic Lamprosauroides goepperti, is described from the Lower Muschelkalk (Anisian, Middle Triassic) of Winterswijk (Netherlands) by Spiekman & Klein (2021).
 * A study on the bone histology and possible affinities of Proneusticosaurus silesiacus is published by Klein & Surmik (2021).
 * Description of a new specimen of Panzhousaurus rotundirostris from the Guanling Formation (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 holotype of that species) and lacking most of the right hindlimb, is described from the Anisian Guanling Formation (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 Katterfeld Formation (Chile) by Poblete-Huanca et al. (2021), representing the first record of a Lower Cretaceous plesiosaur from Chile.
 * A tooth crown of a pliosaurid belonging to the subfamily Brachaucheninae is described from the Cenomanian La Luna Formation (Venezuela) 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 eurymerus is published by Krahl & Witzel (2021).
 * A study on the postcranial materials of xenopsarian plesiosaurs from the Eromanga Basin (Australia), 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 mukulu from the Maastrichtian Mocuio Formation (Angola), 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 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 Campanian–Maastrichtian strata of Antarctica, identified as a non-aristonectine elasmosaurid belonging to the group Weddellonectia, 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 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 Maastrichtian of Argentina, and interpret this finding as the first record of tuberculosis-like infection in a plesiosaur reported to date.

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, 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 tenertesta, and on its implications for the knowledge of the origin of turtles, is published by Lichtig & Lucas (2021), who reject the interpretation of Eunotosaurus africanus and Pappochelys rosinae as stem-turtles.
 * A study on the histology of the carapace and limb bones of Araripemys 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" 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 geographica and Caninemys tridentata is described from the Miocene La Victoria Formation (Colombia) 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 in S. geographica.
 * Redescription and a study on the phylogenetic relationships of Uluops 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 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 Purbeck Limestone Group (United Kingdom), is published by Guerrero & Pérez-García (2021).
 * New fossil material of Plesiochelys is described from the Upper Jurassic (Tithonian) of the Lusitanian Basin (Portugal) 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 thalassochelydian turtles, including a partial hindlimb with well-preserved remains of skin and a large, articulated skeleton of Thalassemys bruntrutana, documenting the presence of particularly elongate forelimbs in this turtle, are described from the Upper Jurassic of Germany 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 turtles.
 * A study on the skeletal anatomy of Manchurochelys manchoukuoensis, based on data from a new specimens from the Lower Cretaceous Yixian Formation (China), is published by Li, Zhou & Rabi (2021).
 * A large, thick-shelled turtle egg, preserving an embryo of a nanhsiungchelyid 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, Australia) 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, pre-dating the extant pig-nosed turtle.
 * Georgalis (2021) describes a large costal of a soft-shelled turtle from the Eocene of Mali, representing the first record of pan-trionychid turtles from the Paleogene of Africa reported to date.
 * New specimens of the tortoises 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 Eocene Willwood Formation and Green River Formation (Wyoming, United States) by Lichtig, Lucas & Jasinski (2021).
 * A study on the phylogenetic relationships of Eocene geoemydids "Ocadia" kehreri and "Ocadia" messeliana from the Messel pit (Germany) is published by Ascarrunz, Claude & Joyce (2021).
 * Description of new fossil material of Bridgeremys pusilla from the Uinta Formation (Utah, 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 from The Bahamas, 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, leaving the Quaternary tortoise known from fossils excavated on the Sal Island in the 1930s without a scientific name.
 * A well-preserved humerus a of giant turtle, representing the first known record of gigantic Mesozoic sea turtles in Africa, is described from the Maastrichtian Dakhla Formation (Egypt) by Abu El-Kheir, AbdelGawad & Kassab (2021).
 * New specimen of Euclastes wielandi is described from the Paleocene (Danian) Hornerstown Formation (New Jersey, United States) by Ullmann & Carr (2021), who interpret this specimen as proving that E. wielandi is a senior synonym 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) Fur Formation (Denmark) by De La Garza et al. (2021).

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 belonging or related to the species D. kaltenbachi is described from the Upper Triassic Chinle Formation (Arizona, 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 and Virginia.
 * A study on bone histology of proterochampsid specimens from the Triassic Chañares Formation (Argentina), aiming to infer history traits related to growth dynamics, ontogenetic changes, dermal armor histogenesis and lifestyle, is published by Ponce et al. (2021).
 * A large phytosaur specimen likely belonging to the species Smilosuchus gregorii, preserved with evidence of pathologies evoking aspects of both osteomyelitis and hypertrophic osteopathy, is described from Norian strata near St. Johns (Arizona, 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 distributions and ecology of phytosaurs, is published by Hoffman, Miller-Camp & Heckert (2021).

Research

 * Revision of putative Carboniferous 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.
 * Footprints of early reptiles, including footprints representing the ichnotaxon Notalacerta missouriensis and footprints possibly belonging to the ichnogenus Notalacerta, are described from the Meisenheim, Tambach, Sulzbach and Standenbühl formations (Pennsylvanian and Cisuralian, Germany) by Marchetti et al. (2021), potentially extending the European record of the ichnogenus Notalacerta back to the Moscovian.
 * Revision of diagnostic characters used to identify mesosaur species is published by Piñeiro et al. (2021), who report that they could not find unambiguous autapomorphies that characterized Brazilosaurus or Stereosternum.
 * Redescription of the holotype and description of the second known specimen of Eudibamus 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 alexanderi is published by Van den Brandt et al. (2021).
 * A study on the anatomy of the postcranial skeletons of Bradysaurus baini, Embrithosaurus schwarzi and Nochelesaurus alexanderi is published by van den Brandt et al. (2021).
 * A study on the skeletal anatomy and phylogenetic relationships of Provelosaurus 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 karpinskii.
 * Tetrapod footprints assigned to the ichnogenus Hyloidichnus, produced by captorhinids or similar reptiles and providing new information on the locomotion of these reptiles, are described from the Permian Pelitic Formation of Gonfaron (Le Luc Basin, Var, France) by Logghe et al. (2021).
 * Description of a new specimen of Anthracodromeus longipes from the Carboniferous Allegheny Group (Ohio, United States), preserving an ungual-bearing manus 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 reptile is described from the upper Panchet Formation (India) by Ezcurra, Bandyopadhyay & Sen (2021), expanding known diversity of Early Triassic reptiles from this formation.
 * A study on the skeletal anatomy, gliding apparatus and phylogenetic relationships of Weigeltisaurus jaekeli, based on data from a nearly complete skeleton from the Upper Permian Kupferschiefer (Germany), is published by Pritchard et al. (2021).
 * Redescription of the anatomy of the skull of Coelurosauravus 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 oxoniensis is published by Griffiths et al. (2021).
 * Putative choristoderan maxilla from the Bathonian Peski locality (Moskvoretskaya Formation; Moscow Oblast, Russia) is reinterpreted as a fossil a member of Lepidosauromorpha similar to Fraxinisaura and Marmoretta by Skutschas et al. (2021), who interpret this specimens as the first known record of basal lepidosauromorphs in the Middle Jurassic of European Russia.
 * Choristoderan vertebrae, representing the first record of choristoderans from the Upper Cretaceous of Asia reported to date, are described from the Turonian Tamagawa Formation (Japan) 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 and the Ellisdale Fossil Site (New Jersey, United States) by Dudgeon et al. (2021), who also attempt to determine possible causes of the apparent rarity of neochoristoderes in Appalachia.
 * A study comparing cervical morphology and neck mobility in Champsosaurus, Simoedosaurus and extant gharial, and evaluating their implications for the knowledge of the feeding behaviour of choristoderans, is published by Matsumoto, Fujiwara & Evans (2021).
 * A study on the phylogenetic relationships of archosauromorph reptiles, aiming to determine the relationships of "protorosaurs", is published by Spiekman, Fraser & Scheyer (2021), who name a new clade Dinocephalosauridae.
 * 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 is published by Nesbitt et al. (2021), who interpret this reptile as an early diverging, but late-surviving, carnivorous member of Azendohsauridae.
 * 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 ontogeny, evaluating their implications for the knowledge of the evolution of patterns of neurocentral suture closure in archosauromorph reptiles and most likely ancestral condition in archosaurs, is published by Heinrich et al. (2021).
 * A study on the anatomy of the skull of the holotype specimen of Hyperodapedon sanjuanensis is published by Gentil & Ezcurra (2021).

Reptiles in general

 * A study comparing species richness of synapsids and reptiles during the Pennsylvanian and Cisuralian, evaluating the impact of the preservation biases, of the effect of Lagerstätten, 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 amniotes, 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 scholtzi, Varanosaurus acutrostris, Orovenator mayorum and Prolacerta broomi, and evaluating the implications of the morphology of the maxillary canal for the knowledge of the phylogenetic placement of varanopids, is published by Benoit et al. (2021).
 * Fischer, Weis & Thuy (2021) describe new ichthyosaur and plesiosaur fossils from successive geological formations in Belgium and Luxembourg 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).