Elasmobranchii is a subclass of Chondrichthyes or cartilaginous fish, including modern sharks, rays, skates, and sawfish. Members of this subclass are characterised by having five to seven pairs of gill slits opening individually to the exterior, rigid dorsal fins and small placoid scales on the skin. The teeth are in several series; the upper jaw is not fused to the cranium, and the lower jaw is articulated with the upper. The details of this jaw anatomy vary between species, and help distinguish the different elasmobranch clades. The pelvic fins in males are modified to create claspers for the transfer of sperm. There is no swim bladder; instead, these fish maintain buoyancy with large livers rich in oil.
Ischyodus is an extinct genus of chimaera. It is the most diverse and long-lived chimaera genus, with over 39 species found worldwide spanning over 140 million years from the Middle Jurassic to the Miocene. Almost all species are only known from tooth plates, with the exception of the Jurassic species I. quenstedti. Complete specimens of I. quenstedti from the Late Jurassic of Germany most closely resemble the genus Callorhinchus amongst living chimaera genera. It is sometimes placed in the "Edaphodontidae", a unclearly defined group of chimaera with an uncertain position within the clade, while other authors place it into Callorhinchidae along with Callorhinchus, a position that has been supported by at least some phylogenetic analyses. It is suggested therefore to probably have had a similar ecology to living Callorhinchus.
Protospinax is an extinct genus of cartilaginous fish from the Early Jurassic to Early Cretaceous of Europe and Russia. The type species, P. annectans, was found in the Solnhofen limestones of southern Bavaria. Formerly known from only two specimens, further museum specimens of P. annectans were discovered at the Museum of Comparative Zoology of Harvard University in the 1990s, having been misidentified as Squatina and Heterodontus. Five more species, all known only from isolated teeth, are also assigned to Protospinax.
Meristodonoides is an extinct genus of hybodont known from the mid-late Cretaceous, with potential records dating back to the Jurassic. It is one of a number of hybodont genera composed of species formerly assigned to Hybodus.
Victor Joseph de l'Isle Thiollière was a French civil engineer, geologist and paleoichthyologist.
Sclerorhynchoidei is an extinct suborder of rajiform rays that had long rostra with large denticles similar to sawfishes and sawsharks. This feature was convergently evolved, recently proposed as 'pristification', and their closest living relatives are actually skates. While they are often called "sawfishes", sawskates is a more accurate common name proposed in 2021 for sclerorhynchoids, which has been subsequently used by other researchers.
Rhinopristiformes is an order of rays, cartilaginous fishes related to sharks, containing shovelnose rays and allied groups.
Synechodontiformes is an extinct order of prehistoric shark-like cartilaginous fish, known from the Permian to the Paleogene. They are considered to be members of Neoselachii, the group that contains modern sharks and rays.
Paracestracion is an extinct genus of heterodontiform sharks from Early Jurassic to Early Cretaceous-aged rocks of England, France, Germany and Luxembourg. The genus was first described in 1911 by Ernst Hermann Friedrich von Koken in Karl Alfred von Zittel.
Synechodus is an extinct genus of shark belonging to the family Palaeospinacidae and order Synechodontiformes. It is known from 16 species primarily spanning from the Late Triassic to Paleocene. The dentition is multicusped and was used for grasping. Several species are known from skeletal remains, including the species Synechodus ungeri from the Late Jurassic of Germany, which shows that it was relatively short with large pectoral fins and a proportionally large head with a round snout. This species is suggested to have reached a body length of 30–40 centimetres (0.98–1.31 ft). Skeletal remains are also known of the species Synechodus dubrisiensis from the Cretaceous of Europe. A skeleton of an indeterminate species is also known from the Early Cretaceous (Albian) of France, with a body length of around 70 centimetres (2.3 ft). Synechodus is suggested to have had two dorsal fins that lacked fin spines, though the number of dorsal fins is unknown in Synechodus ungeri.
Asterodermus is an extinct genus of spathobatid rays from the Jurassic period. A single species, A. platypterus, is described. It is known mainly from the early Tithonian of Germany, including the famous Lagerstätte site of Solnhofen. Additionally, Asterodermus scales have been found among articulated skeletons of neoselachians from the Tithonian of southern Germany.
Belemnobatis is an extinct genus of rays from the Late Jurassic. It has been regarded as related to other Jurassic rays in the family Spathobatidae. It is possible this genus is a wastebasket taxon. It is known from many sites of both Jurassic and Cretaceous age throughout Europe and a single Asian occurrence in the middle Jurassic of Thailand.
Pseudorhina is an extinct genus of squatiniform shark closely related to modern angelsharks. Fossils are known from the Late Jurassic and Early Cretaceous of Europe.
Palaeocarcharias is an extinct genus of shark, known from the Jurassic of Europe. It has only a single named species, Palaeocarcharias stromeri, which is known from exceptionally preserved specimens from the Late Jurassic (Tithonian) of Germany and France. Isolated teeth of indeterminate species from England extend the range of the genus back to the Middle Jurassic (Bathonian). Morphologically, it closely resembles carpet sharks (Orectolobiformes), and is around 1 metre (3.3 ft) in total body length. However, it shares greater similarities in tooth development with mackerel sharks (Lamniformes), including the absence of orthodentine, and has been suggested to the earliest known member of the Lamniformes or a member of a sister group to the Lamniformes. A 2018 study suggested that should be classified as the sole member of the order Palaeocarchariiformes, but a subsequent 2023 study questioned this and favoured placement in Lamniformes. A 2024 study of a specimen from Canjuers suggested that as that it was in fact a true carpet shark, perhaps a member of Orectolobidae.
Egertonodus is an extinct genus of shark-like hybodont fish. It includes E. basanus from the Jurassic of Europe and North Africa and Cretaceous of North America, North Africa and Europe, and E. duffini from the Middle Jurassic of England. Indeterminate remains of the genus have been reported from the Early Cretaceous of Asia. E. basanus is known from preserved skull material, while E. duffini is only known from teeth. The genus is distinguished from Hybodussensu stricto by characters of the skull and teeth. E. basanus, the most common species, is thought to have reached 1.5 m in length. E. fraasi from the Late Jurassic of Germany, known from a poorly preserved full body fossil, was placed in Egertonodus in one study, but this has been subsequently questioned by other authors, due to strong differences in tooth morphology from the type species. Fossils have been found in freshwater and lagoonal environments.
Sphenodus is an extinct genus of shark. It is placed as a member of the extinct family Orthacodontidae, which is either considered to be a member of the extinct order Synechodontiformes, or the modern shark order Hexanchiformes. 29 species have been described, though some of these are likely synonyms, which span from the Early Jurassic (Sinemurian) to Paleocene (Danian). Most species are only known from isolated teeth, though the species Sphenodus macer and Sphenodus nitidus from the Late Jurassic of Germany are known from skeletons. These suggest that it was relatively large, with a body length of 2–3 metres (6.6–9.8 ft), with a fusiform body with a single dorsal fin placed posteriorly without a fin spine. The teeth of Sphenodus consist of a single long, narrow central cusp, with much smaller lateral cusplets. Species of Sphenodus are thought to have been actively swimming predators.
This list of fossil fish research presented in 2025 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 2025.
Chimaeropsis is an extinct genus of cartilaginous fish related to modern chimaeras, known from the Jurassic of Europe.
Apolithabatis is an extinct genus of spathobatid rays from the Late Jurassic Torleite Formation of Germany. The genus contains a single species, A. seioma, known from a single complete, well-preserved specimen.
Aellopobatis is an extinct genus of spathobatid rays from the Late Jurassic Solnhofen Archipelago of Germany. The genus contains a single species, A. bavarica, known from several complete, well-preserved specimens.
