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[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 evolution of fish began about 530 million years ago during the Cambrian explosion. It was during this time that the early chordates developed the skull and the vertebral column, leading to the first craniates and vertebrates. The first fish lineages belong to the Agnatha, or jawless fish. Early examples include Haikouichthys.
Daeschler, Shubin & Jenkins, 2006. Tiktaalik ( / tɪkˈtɑːlɪk /; Inuktitut ᑎᒃᑖᓕᒃ [tiktaːlik]) is a monospecific genus of extinct sarcopterygian (lobe-finned fish) from the Late Devonian Period, about 375 Mya (million years ago), having many features akin to those of tetrapods (four-legged animals). [ 1] Tiktaalik is estimated to ...
Sturgeon. Sturgeon (from Old English styrġa ultimately from Proto-Indo-European * str̥ (Hx)yón - [ 1]) is the common name for the 28 species of fish belonging to the family Acipenseridae. The earliest sturgeon fossils date to the Late Cretaceous, and are descended from other, earlier acipenseriform fish, which date back to the Early Jurassic ...
Dunkleosteus. 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. [ 1]
Sacabambaspis. Sacabambaspis janvieri fossil cast of a specimen from Bolivia . Sacabambaspis is an extinct genus of jawless fish that lived in the Ordovician period. Sacabambaspis lived in shallow waters on the continental margins of Gondwana. [ 1] It is the best known arandaspid with many specimens known.
Synonyms. Placodermata. Placoderms (from Greek πλάξ ( plax, plakos) ' plate ' and δέρμα ( derma) 'skin') [ 1] are vertebrate animals of the class Placodermi, an extinct group of prehistoric fish known from Paleozoic fossils during the Silurian and the Devonian periods. While their endoskeletons are mainly cartilaginous, their head and ...
Living fossil. The coelacanths were thought to have gone extinct 66 million years ago, until a living specimen belonging to the order was discovered in 1938. A living fossil is an extant taxon that phenotypically resembles related species known only from the fossil record. To be considered a living fossil, the fossil species must be old ...