This list of fossil fishes described in 2020 is a list of new taxa of jawless vertebrates, placoderms, acanthodians, fossil cartilaginous fishes, bony fishes, and other fishes of every kind that were described during the year 2020, as well as other significant discoveries and events related to paleoichthyology that occurred in 2020.
New taxa
Jawless vertebrates
Placoderms
Acanthodians
Cartilaginous fishes
Ray-finned fishes
Lobe-finned fishes
Research
A study on the morphology of the osteostracans, evaluating different methods used to determine the morphological variation within this group and its evolution, is published by Ferrón et al. (2020). A study on the morphological diversity of osteostracan headshields, aiming to determine the relationship between their morphological diversity and hydrodynamic performance and its implications for the knowledge of the ecological diversity of the osteostracans, is published by Ferrón et al. (2020). A study aiming to test the alternative hypotheses of placoderm jaw bone homologies, and evaluating their implications for the knowledge of evolution of jaw bones in early jawed vertebrates, is published by King & Rücklin (2020). A study on the fossil dentitions of acanthothoracids is published by Vaškaninová et al. (2020), who report that the teeth of acanthothoracids differed fundamentally from those of arthrodires, and argue that the characteristic traits of acanthothoracid dentition might be ancestral for all jawed vertebrates. Redescription of the anatomy of Walterilepis speciosa, based on data from new fossil material, and a study on the phylogenetic relationships of this species is published online by Lukševičs (2020). Description of the neurocranial anatomy of Ellopetalichthys scheii is published by Castiello et al. (2020). A study aiming to determine whether Titanichthys was a suspension feeder, focusing on mechanical properties of its jaw, is published by Coatham et al. (2020). The earliest fossilized vertebrate embryos reported so far, preserved with an adult specimen of Watsonosteus fletti from the Givetian Eday Flagstone Formation (Orcadian Basin; Scotland, United Kingdom), are described by Newman et al. (2020). Burrow, Newman & den Blaauwen (2020) describe external spiracular elements in Middle Devonian acanthodians from northern Scotland, differing from spiracles of all known extant and extinct fishes, and report the oldest record of elastic cartilage in the fossil record. A study examining the factors influencing the long-term variations of genus-level diversity of elasmobranchs and ray-finned fishes throughout their evolutionary history is published by Guinot & Cavin (2020). Carrillo-Briceño et al. (2020) describe a new elasmobranch assemblage from the Oligocene–Miocene boundary in the Dos Bocas Formation (Ecuador), and evaluate the implications of this assemblage for chronostratigraphic inferences and the knowledge of local paleoenvironment. Two large vertebrae of sharks belonging to the genus Ptychodus, providing new information on the life history and body size of members of the family Ptychodontidae, are described from the Santonian of Spain by Jambura & Kriwet (2020). A study on the evolution of body size in lamniform sharks, including the evolution of gigantism in the lineage of Otodus megalodon, is published by Shimada, Becker & Griffiths (2020). Taxonomic revision of the Oligocene and Miocene sand sharks is published by Hovestadt (2020). A study aiming to determine the linear body dimensions of Otodus megalodon at different life stages is published by Cooper et al. (2020). A study on the class structure of assemblages of specimens of Otodus megalodon in eight previously known formations and in a newly described Miocene locality from northeastern Spain is published by Herraiz et al. (2020), who interpret their findings as indicative of existence of five potential nurseries of these sharks ranging from the Langhian to the Zanclean. An isolated tooth of Cosmopolitodus hastalis from the Miocene of South Korea is described by Yun (2020). A study on the fossil record of the great white shark from the Pliocene of Peru and Chile is published by Villafaña et al. (2020), who interpret their findings as indicating that great white sharks used the Coquimbo locality in Chile as a nursery and Pisco (Peru) and Caldera (Chile) localities as feeding grounds during the Pliocene. A study on the anatomy and phylogenetic relationships of "Urolophus" crassicaudatus is published by Marramà et al. (2020), who transfer this species to the genus Arechia. Collareta et al.