1) Agnathan 2) Jawless fish 3) Jawless vertebrate
Found on
https://www.crosswordclues.com/clue/ostracoderm
Ostracoderms (`shell-skinned`) refers to the armored jawless fishes of the Paleozoic. The term does not often appear in classifications today because it is paraphyletic or polyphyletic, and has no phylogenetic meaning. However, the term is still used as an informal way of loosely grouping together the armored jawless fishes. An innovation of ost.....
Found on
http://en.wikipedia.org/wiki/Ostracoderm
any of an extinct group of small, fishlike Paleozoic vertebrates, members of which belonged to several orders particularly abundant in Late Silurian ... [1 related articles]
Found on
http://www.britannica.com/eb/a-z/o/37
Ostracoderms (also called Agnaths) are extinct, primitive, armored, jawless fish that lived during from the Ordovician period to the Devonian period. These vertebrates had bodies that were protected by bony plates and scales. Fossils have been found in North America and Europe. Some ostracoderms include the Pteraspids.
Found on
http://www.enchantedlearning.com/subjects/dinosaurs/glossary/
[
n] - extinct fishlike jawless vertebrate having a heavily armored body
Found on
http://www.webdictionary.co.uk/definition.php?query=ostracoderm
noun extinct fishlike jawless vertebrate having a heavily armored body; of the Paleozoic
Found on
https://www.encyclo.co.uk/local/20974
any of several extinct jawless fishes of the Ordovician, Silurian, and Devonian periods, having the body enclosed in an armor of bony plates.
Found on
https://www.infoplease.com/dictionary/ostracoderm
No exact match found.
