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Placoderms were among the first jawed fish (their jaws likely evolved from the first pair of gill arches), as well as the first vertebrates to have true teeth. They were also the first fish clade to develop pelvic fins , the second set of paired fins and the homologous precursor to hindlimbs in tetrapods .
Helicoprion bessonovi, teeth at the front of the lower jaw (reversed for more natural position) Restoration of Romerodus (Caseodontidae). The Eugeneodontida, sometimes also called Eugeneodontiformes, is an extinct and poorly known order of cartilaginous fishes.
Andreolepis was capable of shedding its teeth by basal resorption, which is considered a rather primitive mode of tooth replacement. [6] This makes it informative about the evolution of teeth. [6] Fossil remains are mostly limited to scales, platelets and fragmented bones. At first only the species A. hedei was described.
Xenacanthida (or Xenacanthiformes) is an order or superorder of extinct shark-like chondrichthyans (cartilaginous fish) known from the Carboniferous to Triassic. They were native to freshwater, marginal marine and shallow marine habitats. [1] Some xenacanths may have grown to lengths of 5 m (16 ft). [2]
The study of prehistoric fish is called paleoichthyology. A few living forms, such as the coelacanth are also referred to as prehistoric fish, or even living fossils, due to their current rarity and similarity to extinct forms. Fish which have become recently extinct are not usually referred to as prehistoric fish. They were very different from ...
The word paleoart is also used in an informal sense as a name for prehistoric art, most often cave paintings. [ 3 ] The term "paleoart"–which is a compound of paleo , the Ancient Greek word for "old", and "art"–was introduced in the late 1980s by Mark Hallett for art that depicts subjects related to paleontology , [ 4 ] but is considered to ...
Dunkleosteus is an extinct genus of large arthrodire ("jointed-neck") fish that existed during the Late Devonian period, about 382–358 million years ago.It was a pelagic fish inhabiting open waters, and one of the first apex predators of any ecosystem.
Pterichthyodes is a genus of antiarch placoderm fishes from the Devonian period. Its fossils have been discovered in Scotland. [1] They were one of the first species recognized for what they were, as their fossils are common in the Old Red Sandstone formation studied by geologists in the early 19th century.