This list of fossil fish research presented in 2023 is a list of new fossil taxa of jawless vertebrates, placoderms, cartilaginous fishes, bony fishes, and other fishes that were described during the year, as well as other significant discoveries and events related to paleoichthyology that occurred in 2023.
Jawless vertebrates NameNoveltyStatusAuthorsAgeType localityLocationNotesImagesAmaltheolepis terranoviSp. novValidBlom et al.Devonian (Emsian)Shevchenkinskaya Formation()A member of Thelodonti belonging to the group Thelodontiformes and the family Turiniidae.CaeruleumGen. et sp. novHuangEarly CretaceousJiufotang FormationA lamprey. The type species is C. miraculum.Dayongaspis colubraSp. novValidZhang et al.Silurian (Telychian)Xiushan FormationA member of Galeaspida belonging to the family Dayongaspidae.FoxaspisGen. et sp. novGai et al.Devonian (Pragian)Xiaoshan Formation(Guangxi)A member of Galeaspida belonging to the group Polybranchiaspidiformes and the family Duyunolepididae. The type species is F. novemura.Jiangxialepis rongiSp. novLiu et al.Silurian (Telychian)Tataertag FormationA member of Galeaspida belonging to the family Shuyuidae.SquirmariusGen. et sp. novValidMcCoy et al.Carboniferous (Pennsylvanian)Mazon Creek fossil beds()A member of Cyclostomi. The type species is S. testai.XiyuichthysNom. et sp. novShan et al.SilurianTataertag FormationA member of Galeaspida belonging to the family Xiushuiaspidae; a replacement name for Xiyuaspis Liu et al. (2019). Shan et al. (2023) also named a new species X. lixiensis from the Telychian Qingshui Formation (Jiangxi, China).YanliaomyzonGen. 2 sp. novWu, Janvier & ZhangJurassic (Callovian and Oxfordian)Tiaojishan FormationA lamprey. The type species is Y. occisor; genus also includes Y. ingensdentes.
Jawless vertebrate research A study on the anatomy and affinities of Lasanius is published by Reeves et al. (2023), who interpret this vertebrate as a stem-cyclostome. Dearden et al. (2023) describe the cranial anatomy of Eriptychius americanus, provide evidence of the presence of a symmetrical set of cartilages interpreted as the preorbital neurocranium, and report that the studied cartilages filled out the head and closely supported the dermal skeleton (in that they were closer to the cranial anatomy of osteostracans and galeaspids than cyclostomes), but were not fused into a single unit around the brain (more closely resembling the cranial anatomy of cyclostomes than osteostracans, galeaspids and jawed vertebrates in that aspect). A study on the interaction of fluid flow with 2D models of heterostracan oral plate denticles is published by Grohganz et al. (2023), who interpret their findings as indicating that the studied denticles were not an adaptation to suspension feeding.
Placoderms NameNoveltyStatusAuthorsAgeType localityLocationNotesImagesBothriolepis dairbhrensisSp. novValidDupret et al.Devonian (Givetian)Valentia Slate FormationChahuaqingolepisGen. et sp. novValidLiu et al.DevonianTanglishu FormationA member of the family Bothriolepididae. The type species is C. magniporus.Dunkleosteus tuderensisSp. novLebedev in Lebedev et al.Devonian (Famennian)Bilovo Formation()Sherbonaspis talimaaeSp. novValidPlax & LukševičsDevonian (probably Emsian)Lepel BedsA member of Asterolepidoidei belonging to the family Pterichthyodidae.ValentinaspisGen. et sp. novValidPlax & NewmanDevonian (Emsian)A member of the family Arctolepididae. The type species is V. profundus.
Placoderm research Evidence from the study of the skull of Kolymaspis sibirica, interpreted as indicating that the sixth branchial arch was probably the one that was incorporated into the vertebrate shoulder girdle, is presented by Brazeau et al. (2023). Brazeau et al. (2023) describe a near-complete "acanthothoracid" upper jaw from the Devonian (Pragian) Yamaat Gol locality (Mongolia), and interpret this finding as indicating that the morphology and function of "acanthoracid" jaws resemble generalized "placoderm" conditions seen also in arthrodires and rhenanids. Redescription and a study on the affinities of Bothriolepis sinensis is published by Luo et al. (2023). Evidence of different patterns of phylogenetic and taxic diversity of Arthrodira throughout their evolutionary history is presented by Xue et al. (2023), who find evidence robust correlation between declines of phylogenetic diversity and significant global events during the Devonian, especially the late Givetian event, the Late Devonian extinction and the Hangenberg event. Engelman (2023) attempts to determine body size of Dunkleosteus terrelli, recovering the body lengths of between 3.1 and 3.5 m for typical adults and ~4.1 m for the largest individuals; in a subsequent study the author reevaluates the methodology and length estimates used by Ferrón, Martinez-Perez & Botella (2017), and argues that length estimates for Dunkleosteus based on the mouth dimensions of extant sharks are not reliable, as arthrodires have proportionally larger mouths than sharks. Cui et al. (2023) describe a near-complete post-thoracic exoskeleton of Entelognathus primordialis from the Silurian Kuanti Formation (China), reporting the presence of an anal fin spine in the studied specimen, previously known only in stem cartilaginous fishes, as well as striking similarities of the scales and squamation of the studied specimen to those of bony fishes, including the presence of rhomboid scales with the peg-and-socket articulation previously considered a synapomorphy of bony fishes.
Cartilaginous fishes NameNoveltyStatusAuthorsAgeType localityLocationNotesImagesAtlantobatisGen. et sp. novGuinot et al.Late CretaceousA batomorph elasmobranch. The type species is A. acrodonta.CavusodusGen. et sp. novValidItanoCarboniferous (late Viséan–early Serpukhovian)()A member of Petalodontiformes belonging to the family Janassidae. The type species is C. whitei.Corysodon multicristatusSp. novValidBatchelor & DuffinEarly Cretaceous (Aptian)Atherfield Clay FormationA neoselachian shark.
Possibly a Carcharhiniforme.Coupatezia caseiSp. novGuinot et al.Late CretaceousA batomorph elasmobranch.CrioselacheGen. et sp. novValidPauliv et al.Permian (Asselian)Campo Mourão FormationPossibly a member of the family Symmoriidae. The type species is C. wittigi.'Dasyatis' reticulataSp. novGuinot et al.Late CretaceousA batomorph elasmobranch.DasyomyliobatisGen. et sp. novValidMarramà et al.Eocene (Ypresian)Monte Bolca LagerstätteA member of Myliobatiformes belonging to the new family Dasyomyliobatidae. The type species is D. thomyorkei.Denaea patulaSp. novIvanov in Ivanov, Alekseev & NikolaevaCarboniferous (Viséan)A member of Symmoriiformes.DesiniaGen. et sp. novValidIvanov in Ivanov et al.Permian()A member of the family Sphenacanthidae. The type species is D. radiata. Published online in 2023, but the issue date is listed as December 2022.FairchildodusGen. et sp. novChahudPermian (Cisuralian)Irati FormationA member of Holocephali. The type species is F. rioclarensis.FunicristataGen. et sp. novValidBurrow in Burrow, Murphy & TurnerSilurian (Přidolí)Roberts Mountains Formation()An acanthodian of uncertain affinities. The type species is F. nevadaensis.Hemipristis tanakaiSp. novTomita, Yabumoto & KugaOligoceneYamaga FormationA species of Hemipristis.KarpinskiprionGen. et comb. novValidLebedev & Itano in Lebedev et al.Carboniferous()A member of the family Helicoprionidae. The type species is "Helicoprion" ivanovi Karpinsky (1924).Lissodus tumidoclavusSp. novValidDuffin, Heckert & HancoxEarly TriassicBurgersdorp FormationA member of Hybodontoidea.LuopingselacheGen. et sp. novWen et al.Middle Triassic (Anisian)A member of the family Lonchidiidae. Genus includes new species L. striata.MaghriboselacheGen. et sp. novKlug et al.Late DevonianA member of the family Cladoselachidae. The type species is M. mohamezanei.OrcadacanthusGen. et comb. novValidNewman et al.DevonianOrcadian BasinA member of Acanthodiformes belonging to the family Mesacanthidae. The type species is "Acanthodes" pusillus Agassiz (1844).Phosphatodon cretaceusSp. novGuinot et al.Late CretaceousA batomorph elasmobranch.Physogaleus onkensisSp. novBoulemia & AdnetPaleogeneKef Esnoun FormationPtychotrygon ameghinorumSp. novBegat et al.Late Cretaceous (Cenomanian)Mata Amarilla FormationPtychotrygon nazeensisSp. novGuinot et al.Late CretaceousA batomorph elasmobranch.'Rhinobatos' popenguinensisSp. novGuinot et al.Late CretaceousA batomorph elasmobranch.SowibatosGen. et sp. novGuinot et al.Late CretaceousA batomorph elasmobranch. The type species is S. minimus.Squatinactis multicuspidatusSp. novIvanov in Ivanov, Alekseev & NikolaevaCarboniferous (Viséan)StrigilodusGen. et sp. novValidHodnett et al.Carboniferous (Viséan)Ste. Genevieve Formation()A member of Petalodontiformes belonging to the family Janassidae. The type species is S. tollesonae.Strophodus atlasensisSp. novValidStumpf et al.Middle Jurassic (Bajocian)Agoudim FormationA member of Hybodontiformes belonging to the family Hybodontidae and the subfamily Acrodontinae.SulcacanthusGen. et sp. novValidItano & DuffinCarboniferous (Viséan)St. Louis Formation()A chimaera belonging to the group Squalorajoidei. The type species is S. schachti.TerangabatisGen. et sp. novGuinot et al.Late CretaceousA batomorph elasmobranch. The type species is T. thiami.
Cartilaginous fish research Fossil material of members of the genera Pucapampella and Zamponiopteron is described from the Devonian (Eifelian) Chagrapi Formation by Zevallos-Valdivia et al. (2023), representing the first record of Paleozoic vertebrates from Peru reported to date. Burrow & Desbiens (2023) describe dental elements of Doliodus latispinosus from the Devonian York River Formation (Quebec, Canada), finding no justification for assigning the studied isolated dental elements to a species distinct from D. latispinosus from the Atholville beds (New Brunswick, Canada). A study on the musculoskeletal anatomy of Iniopera is published by Dearden, Herrel & Pradel (2023), who interpret the anatomy of Iniopera as unsuited to durophagy, and consider it to be likely a high-performance suction-feeder. Fossil material of members of at least seven species belonging to the genus Ptychodus is described from the ?Cenomanian–Santonian of the Malyy Prolom area (Ryazan Oblast, Russia) by Amadori et al. (2023), who also report the northernmost occurrence of Ptychodus in Europe from the Cenomanian of Varavinsky ravine area (Moscow Oblast, Russia), and interpret the studied fossils as indicating that Late Cretaceous epicontinental seas of the Russian platform were important areas of diversification and spread of Ptychodus. Amadori et al. (2023) report the discovery of teeth of various species belonging to the genus Ptychodus from the Cenomanian and Turonian deposits of Ukraine, including teeth of cuspidate (P. altior) and un-cuspidate species (P. decurrens, P. latissimus, P. marginalis and P. polygyrus), and argue that the availability of diverse shelled invertebrates in epicontinental seas might have favored the diversification of Ptychodus. Ghosh et al. (2023) report the discovery of a new assemblage of lamniform shark teeth from the Aptian Habur Formation (India), including teeth of Dwardius and possibly of Eostriatolamia which may be some of the globally oldest record of these taxa. A study on the teeth of Megachasma applegatei is published by Krak & Shimada (2023), who find that the range of the morphometric variation of teeth of M. applegatei is larger than that of teeth of extant megamouth shark, with different tooth types corresponding to tooth types present in the smalltooth sand tiger. Shimada et al. (2023) describe tessellated calcified cartilage and placoid scale associated with a tooth set of Otodus megalodon from the Miocene strata in Japan, and interpret the morphology of the studied material as indicating that O. megalodon was generally a slow cruising shark.