Placodermi

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Placodermi

[‚pla·kə′dər·mē]
(paleontology)
A large and varied class of Paleozoic fishes characterized by a complex bony armor covering the head and the front portion of the trunk.

Placodermi

 

a class of extinct fishes that lived during the Devonian. Their length was up to 5–6 m. The head and anterior part of the trunk were covered with an armor of bony plates of cutaneous origin. The plates were nodular and ridged. The head and trunk sections of the armor were articulated, and the jaws consisted of pointed bony plates. There were two subclasses: Arthrodira and Antiarchi (which included the genus Bothriole-pis).

REFERENCE

Drushits, V. V., and O. P. Obrucheva. Paleontologiia, 2nd ed. [Moscow] 1971.
References in periodicals archive ?
2003), disarticulated cephalaspids, placoderms and acanthodians, and both articulated and disarticulated eurypterids (Miller 2007a).
Like Entelognathus, Qilinyu had a three-part jaw, though the creature looked a bit more like a typical placoderm, Ahlberg says.
It is a member of an extinct group of fish called placoderms whose heads and bodies were mostly covered in armor, with jaws that had bony plates, called gnathal plates, which acted like teeth.
Placoderms were also some of the first vertebrates to have necks separating their heads and shoulder bones, allowing the fish to move their heads independently of the rest of their bodies.
Bottom line: not part of a placoderm, or of any other kind of Devonian fish.
The Late Devonian placoderm Aspidichthys Newberry, 1873 from the Holy Cross Mountains, Poland.
The Andreyevka-2 community including antiarch placoderms, acanthodians, chondrichthyans and osteichthyans, as well as tetrapods, has been discussed on repeated occasions by the first author of this paper (Lebedev 1986, 1992, 2013; Lebedev et al.
They are represented by undetermined placoderms, acanthodians and sarcopterygians (Fig.
The ichthyoassemblage belongs to the Pycnosteus tuberculatus psammosteid Zone and the Asterolepis delli placoderm Zone, and includes the psammosteids Pycnosteus tuberculatus (Rohon), Ganosteus stellatus Rohon (Glinskiy 2012); the placoderms Actinolepis sp.
However, a closer inspection by Long and research team revealed they were the tiny bones of unborn fish from two adult species of arthrodires (Incisoscutum ritchiei) - the biggest and most diverse placoderm group.