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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 ...
This list of fossil fish research presented in 2023 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 2023.
Dunkleosteus terrelli is one of the largest known placoderms, with its maximum size being variably estimated as anywhere from 4.1–10 metres (13–33 ft) by different researchers. [ 32 ] [ 33 ] [ 11 ] [ 34 ] [ 2 ] However, most cited length estimates are speculative and lack quantitative or statistical backing, and lengths of 5 m (16 ft) or ...
This list of placoderms is an attempt to create a comprehensive listing of all genera from the fossil record that have ever been considered to be members of the class Placodermi. This list excludes purely vernacular terms. It includes all commonly accepted genera, but also genera that are now considered invalid, doubtful (nomina dubia), or were ...
see text for list. Arthrodira (Greek for "jointed neck") is an order of extinct armored, jawed fishes of the class Placodermi that flourished in the Devonian period before their sudden extinction, surviving for about 50 million years and penetrating most marine ecological niches. Arthrodires were the largest and most diverse of all groups of ...
Bothriolepis is a genus placed within the placoderm order Antiarchi. The earliest antiarch placoderms first appeared in the Silurian period of the Paleozoic Era and could be found distributed on every paleocontinent by the Devonian period. [5] The earliest members of Bothriolepis appear by the Middle Devonian.
Acanthothoraci. Acanthothoraci ( spine chests) is an extinct group of chimaera-like placoderms closely related to the rhenanid placoderms. Superficially, the acanthoracids resembled scaly chimaeras and (relatively) heavily armored ptyctodonts. They were distinguished from chimaeras by their large scales and plates, a pair of large spines that ...
Evolution of fish. The Devonian period (419–359 Mya), also known as the Age of Fishes, saw the development of early sharks, armoured placoderms and various lobe-finned fish, including the tetrapod transitional species. The evolution of fish began about 530 million years ago during the Cambrian explosion. It was during this time that the early ...