This list of fossil reptiles described in 2023 is a list of new taxa of fossil reptiles that were described during the year 2023, as well as other significant discoveries and events related to reptile paleontology that occurred in 2023.
Squamates NameNoveltyStatusAuthorsAgeType localityLocationNotesImagesBauersaurusGen. et sp. novValidČerňanský et al.EoceneQuercy Phosphorites FormationA pan-gekkotan. The type species is B. cosensis.BentiabasaurusGen. et sp. nov.Polcyn, Schulp & GonçalvesLate Cretaceous (Maastrichtian)Mocuio FormationA mosasaurine belonging to the group Plotosaurini. The type species is B. jacobsi.BifurcodentodonGen. et sp. novČerňanský et al.Eocene (Ypresian)An iguanian belonging to the group Pleurodonta. The type species is B. ragei.Carentonosaurus algorensisSp. novValidCabezuelo-Hernández & Pérez-GarcíaLate Cretaceous (Cenomanian)Arenas de Utrillas FormationA member of Pythonomorpha.Carentonosaurus soaresiSp. novPimentel et al.Late Cretaceous (Cenomanian)A member of Pythonomorpha. Berrocal-Casero et al. 2024 placed it in the new genus SegurasaurusCryptobicuspidonGen. et sp. novCarvalho & SantucciEarly Cretaceous (Aptian)Quiricó FormationA member of Polyglyphanodontia. The type species is C. pachysymphysealis. Announced in 2023; the final article version will be published in 2024.DeccansaurusGen. et sp. novYadav et al.Late Cretaceous-PaleoceneDeccan Intertrappean Beds A possible member of Cordyliformes. The type species is D. palaeoindicus.Ectenosaurus shannoniSp. novValidKiernan & EbersoleLate Cretaceous (Campanian)Mooreville Chalk()A mosasaur belonging to the subfamily Plioplatecarpinae.Ectenosaurus tlemonectesSp. novValidKiernan & EbersoleLate Cretaceous (Coniacian-Campanian)Niobrara Formation()A mosasaur belonging to the subfamily Plioplatecarpinae.Eoconstrictor barnesiSp. novValidPalci et al.Eocene (Lutetian)Geiseltal LagerstätteA snake belonging to the group Booidea.Eryx linxiaensisSp. nov.Shi et al.MioceneLiushu FormationA species of Eryx.Halisaurus hebaeSp. novShaker et al.Late Cretaceous (Maastrichtian)Dakhla FormationA mosasaur belonging to the subfamily Halisaurinae. Announced in 2023; the final article version will be published in 2024.HelioscoposGen. et sp. novValidMeyer et al.Late Jurassic (Tithonian)Morrison Formation()A member of the family Ardeosauridae. The type species is H. dickersonae.JormungandrGen. et sp. nov.Zietlow, Boyd & van Vranken Late Cretaceous (Campanian)Pierre Shale ()A mosasaur belonging to the subfamily Mosasaurinae. The type species is J. walhallaensis.LimnoscansorGen. et sp. novValidMeyer et al.Late Jurassic (Tithonian)Solnhofen LimestoneA member of the family Ardeosauridae. The type species is "Homoeosaurus" digitatellus Grier 1914.MegapterygiusGen. et sp. novValidKonishi et al.Late Cretaceous (Campanian/Maastrichtian)Toyajo FormationA mosasaurine mosasaur. The type species is M. wakayamaensis.SarabosaurusGen. et sp. novPolcyn et al.Late Cretaceous (Turonian)Tropic Shale ()A mosasaur belonging to the subfamily Plioplatecarpinae. The type species is S. dahli.StelladensGen. et sp. novValidLongrich et al.Late Cretaceous (Maastrichtian)Ouled Abdoun BasinA mosasaurid belonging to the clade Mosasaurinae. Genus includes new species S. mysteriosus.SullivanosaurusGen. et sp. novČerňanský, Tabuce & VidalencEocene (MP 10–11)Quercy Phosphorites FormationA glyptosaurine. The type species is S. gallicus.Yaguarasaurus regiomontanusSp. novRivera-Sylva et al.Late Cretaceous (Turonian-Coniacian)Agua Nueva FormationA mosasaur belonging to the subfamily Plioplatecarpinae. Announced in 2023; the final article version was published in 2024.YechilacertaGen. et sp. novXing, Niu, & EvansLate Cretaceous (Maastrichtian)Hekou FormationA member of Polyglyphanodontia. The type species is Y. yingliangia.
Squamate research Redescription of Palaeogekko risgoviensis is published by Villa (2023), who confirms the validity of this species as a distinct taxon, and interprets it as a non-eublepharid gekkonoid of uncertain affinities. Thorn et al. (2023) describe new fossil material of Aethesia frangens from the Pleistocene of Australia, interpret it as a large-bodied (approximately 2.4 kg) blue-tongued skink, and transfer it to the genus Tiliqua. Lacertid, blanid and anguid fossil material, including one of the oldest records of the genus Blanus reported to date, is described from the Early Miocene localities Montaigu-le-Blin and Crémat (France) by Čerňanský (2023), expanding known spatial and temporal distribution of Blanus cf. gracilis during the Early Miocene. Redescription of Uquiasaurus heptanodonta is published by Scanferla & Díaz-Fernández (2023), who interpret the type series of this species as a fossil bone assemblage composed by more than one species of Liolaemus, extending known fossil record of the latter genus. Hamilton et al. (2023) report the discovery of the fossil material of cf. Palaeosaniwa canadensis from the Campanian Wapiti Formation (Alberta, Canada), representing the northernmost definitive occurrence of Monstersauria in the Upper Cretaceous of North America reported to date. Loréal et al. (2023) describe new fossil material of Pseudopus pannonicus from the Neogene localities across Moldova, Russia and Ukraine, including fossils from the Turolian localities Gaverdovsky and Volchaya Balka in North Caucasus representing the easternmost or some of the easternmost known occurrences of this species, and revise the diagnostic features of P. pannonicus. Georgalis, Mennecart & Smith (2023) describe two teeth of a probable member of the genus Varanus from the Miocene deposits from the Hüenerbach locality (Switzerland), representing of the oldest occurrences of the genus from Europe. A specimen of the ammonite Mammites nodosoides, preserved with bite traces interpreted as most likely resulting from a lethal attack of a mosasaur directed at the apertural part of the ammonite with the head and arm crown, is described from the Turonian Bílá Hora Formation (Czech Republic) by Mazuch et al. (2023). Evidence from tooth microwear of mosasaurs from the type area for the Maastrichtian, interpreted as indicative of preferences for vertebrate and/or invertebrate prey in different mosasaur taxa but not indicative of strict dietary partitioning, is presented by Holwerda et al. (2023). A humerus of a mosasaurine related to Plotosaurus beninsoni and members of the genus Mosasaurus is described from the Maastrichtian López de Bertodano Formation (Antarctica) by O'Gorman et al. (2023), expanding known diversity of Antarctic mosasaurines. LeBlanc et al. (2023) report that tooth replacement in extant snakes occurs by resorption of dentine by odontoclasts from within the pulp of the tooth, and that this mechanism was already present in Yurlunggur and Portugalophis. A study on the evolution of the snake brain, based on data from extant and fossil taxa, is published by Macrì et al. (2023), who interpret their findings as indicative of a burrowing lifestyle with opportunistic behavior at the origin of the crown group of snakes. A palaeophiid vertebra tentatively referred to the genus Pterosphenus is described from the Eocene Ameki Formation (Nigeria) by Georgalis (2023), expanding known diversity of palaeophiids from Nigeria. Averianov (2023) describes new fossil material of Pterosphenus muruntau from the Eocene (Bartonian) deposits from the Dzheroi 2 locality in the Central Kyzylkum Desert (Uzbekistan), and considers P. muruntau to be a valid species. Alfonso-Rojas et al. (2023) describe new fossil material of Colombophis from the Miocene La Victoria and Villavieja formations (Colombia), and interpret its anatomy as supporting the placement of Colombophis among the alethinophidians. Shi et al. (2023) describe an assemblage of early Pliocene snake fossils entombed with the mammalian fauna from Houxushan (Queshan, Henan, China), and interpret the studied fossils as indicative of a warmer and more humid climate in this region during the early Pliocene. Bolet (2023) describes an assemblage of squamate fossils from the Eocene locality of Mazaterón (Spain), providing evidence of the persistence of glyptosaur and anguine anguids, iguanids and lacertids through most of the Iberian Eocene, and including one of the oldest records of amphisbaenians in Europe after the apparent gap in their European fossil record in the MP11–MP15 interval. Lofgren et al. (2023) describe new fossil material of squamates from the Uintan, Chadronian and Whitneyan strata in Montana (United States), including the first records of varanids, Calamagras and a possible member of the genus Peltosaurus from the Tertiary depositional basins of southwest Montana, and the first record of Aciprion formosum from the state and from the Whitneyan strata. Georgalis et al. (2023) describe fossil material of lizards and snakes from the Miocene localities in Anatolia (Turkey), including fossil remains tentatively referred to chameleons, potentially representing the oldest occurrences of chameleons from Asia reported to date.
Ichthyosauromorphs Ichthyosauromorph research A study on the skull morphology of Hupehsuchus nanchangensis, based on data from new specimens from the Lower Triassic Jialingjiang Formation (China), is published by Fang et al. (2023), who find the shape of the skull roof and snout of H. nanchangensis to be highly convergent with modern baleen whales, and interpret Hupehsuchus as likely employing continuous ram filter feeding as in extant bowhead and right whales. Kear et al. (2023) describe ichthyopterygian fossil material (including 11 vertebral centra which are substantially larger than those of typical basal ichthyosauriforms) from the Lower Triassic Vikinghøgda Formation (Svalbard, Norway), interpreting the internal structure of the studied bones as indicating that they belonged to a fully pelagic animal, and argue that ichthyosauromorphs might have originated before the Permian–Triassic extinction event. Engelschiøn et al. (2023) use radiography and computed tomography to reveal taxonomically significant details of the skeletal anatomy of a mixosaurid specimen from the Middle Triassic Botneheia Formation (Svalbard, Norway), and interpret it as a member of the genus Phalarodon with affinities to P. atavus. A study on three gravid Mixosaurus specimens from the Middle Triassic Besano Formation at the Monte San Giorgio locality at the Swiss-Italian border is published by Miedema et al. (2023), who report that two of the studied specimens were preserved with fetuses with tail-first birth position while the third specimen was preserved with fetuses with head-first birth position, propose that a slight preference for tail-first birth likely arose at the base of the Merriamosauria, and argue that fetal orientation at birth in ichthyosaurs was more likely to be related to expulsion mechanics during birth or to maternal stress induced from the fetal orientation during pregnancy than to the need for reduction of asphyxiation risk. A study on the cranial ontogeny of Mixosaurus cornalianus, providing evidence of developmental patterns in the early ontogenetic stages that were reminiscent of the probable ancestral reptile condition, is published by Miedema et al. (2023). A study on the ecomorphological variation of skulls and teeth of members of the genus Temnodontosaurus, providing evidence of a range of configurations allowing prey to be captured and processed in different ways by members of different species and possibly indicative of niche partitioning, is published by Bennion et al. (2023).