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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 ...
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.
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 ...
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 placoderms. [1]
Romundina is a small, heavily armored extinct genus of acanthothoracid placoderms which lived in shallow marine environments in the early Devonian (Lochkovian). [1][2] The name Romundina honors Canadian geologist and paleontologist Dr. Rómundur (Raymond) Thorsteinsson of Calgary, Alberta, Canada. Romundina are believed to have lived on Earth ...
List of placoderm genera. 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 ...
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 ...
Antiarchi ("opposite anus") is an order of heavily armored placoderms. The antiarchs form the second-most successful group of placoderms after the arthrodires in terms of numbers of species and range of environments. The order's name was coined by Edward Drinker Cope, who, when examining some fossils that he thought were armored tunicates ...