''Ageleodus'' is an extinct

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

cartilaginous fish Chondrichthyes (; ) is a class of jawed fish that contains the cartilaginous fish or chondrichthyans, which all have skeletons primarily composed of cartilage. They can be contrasted with the Osteichthyes or ''bony fish'', which have skeleto ...

from the

Paleozoic The Paleozoic ( , , ; or Palaeozoic) Era is the first of three Era (geology), geological eras of the Phanerozoic Eon. Beginning 538.8 million years ago (Ma), it succeeds the Neoproterozoic (the last era of the Proterozoic Eon) and ends 251.9 Ma a ...

era. It is known from two species, both of which are based upon isolated teeth. ''A. pectinatus'' is known from the

Carboniferous The Carboniferous ( ) is a Geologic time scale, geologic period and System (stratigraphy), system of the Paleozoic era (geology), era that spans 60 million years, from the end of the Devonian Period Ma (million years ago) to the beginning of the ...

Europe Europe is a continent located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south, and Asia to the east ...

and

North America North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...

.Downs, Jason & Daeschler, Edward. (2001). Variation within a large sample of Ageleodus pectinatus teeth (Chondrichthyes) from the Late Devonian of Pennsylvania, U.S.A. Journal of Vertebrate Paleontology – J VERTEBRATE PALEONTOL. 21. 811–814. 10.1671/0272-4634(2001)021 811:VWALSO.0.CO;2. ''A. altus'' was described in 2006 from the Carboniferous of Australia. Four teeth from the

Tournaisian The Tournaisian is in the ICS geologic timescale the lowest stage or oldest age of the Mississippian, the oldest subsystem of the Carboniferous. The Tournaisian age lasted from Ma to Ma. It is preceded by the Famennian (the uppermost st ...

deposits of

Canning Basin The Canning Basin is a geological basin located in Western Australia. Deposition of sediments began after early-Ordovician thermal subsidence, and continued into the Early Cretaceous. The Basin covers approximately 507,000 km2 of which app ...

probably present another Australian species although their shape is likely caused by physical wear rather than species features. This genus is also known from the

Famennian The Famennian is the later of two faunal stages in the Late Devonian epoch. The most recent estimate for its duration is that it lasted from around 371.1 to 359.3 million years ago. An earlier 2012 estimate, still used by the International Commis ...

of the

Catskill formation The Devonian Catskill Formation or the Catskill Clastic Wedge is a unit of mostly terrestrial sedimentary rock found in Pennsylvania and New York. Minor marine layers exist in this thick rock unit (up to ). It is equivalent to the Hampshire Fo ...

at the Red Hill Site in Hyner,

Pennsylvania Pennsylvania, officially the Commonwealth of Pennsylvania, is a U.S. state, state spanning the Mid-Atlantic (United States), Mid-Atlantic, Northeastern United States, Northeastern, Appalachian, and Great Lakes region, Great Lakes regions o ...

. A study of 382 specimens from the site showed the strong

heterodont In anatomy, a heterodont (from Greek, meaning 'different teeth') is an animal which possesses more than a single tooth morphology. Human dentition is heterodont and diphyodont as an example. In vertebrates, heterodont pertains to animals wher ...

y of this genus, which varies widely in tooth length and cusp number. This study described them as ''A. pectinatus'', but the paper which described ''A. altus'' tentatively labeled them ''Ageleodus'' cf. ''A. altus''. While generally considered a

chondrichthyan Chondrichthyes (; ) is a class (biology), class of jawed fish that contains the cartilaginous fish or chondrichthyans, which all have skeletons primarily composed of cartilage. They can be contrasted with the Osteichthyes or ''bony fish'', which ...

, it has eluded classification into any known order or family.

References

Fossils of the United States Devonian cartilaginous fish Carboniferous cartilaginous fish Cartilaginous fish genera {{paleo-cartilaginous-fish-stub