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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 .
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.
Helicoprion is an extinct genus of shark-like [1] eugeneodont fish. Almost all fossil specimens are of spirally arranged clusters of the individuals' teeth, called "tooth whorls", which in life were embedded in the lower jaw. As with most extinct cartilaginous fish, the skeleton is mostly unknown.
[8] [25] Coelacanths are large, plump, lobe-finned fish that can grow to more than 2 m (6.6 ft) and weigh around 90 kg (200 lb). [26] They are estimated to live up to 100 years, based on analysis of annual growth marks on scales, and reach maturity around the age of 55; [ 27 ] the oldest known specimen was 84 years old at the time of its ...
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 ...
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 ...
Ornithoprion is a genus of extinct cartilaginous fish in the family Caseodontidae. The only species, O. hertwigi, lived during the Moscovian stage of the Pennsylvanian, between 315.2 to 307 million years ago, and is known from black shale deposits in what is now the Midwestern United States.
All lobe-finned fish possess teeth covered with true enamel. Lobe-finned fish, such as coelacanths and lungfish , were the most diverse group of bony fish in the Devonian. Taxonomists who subscribe to the cladistic approach include the grouping Tetrapoda within the Sarcopterygii, and the tetrapods in turn include all species of four-limbed ...