Ostracoderms (lit. 'shell-skins') are the armored jawless fish of the Paleozoic Era. The term does not often appear in classifications today because it is paraphyletic (excluding jawed fishes) (may also be polyphyletic if anaspids are closer to cyclostomes) and thus does not correspond to one evolutionary lineage. However, the term is still used as an informal way of loosely grouping togethe… Webostracoderms. Definition in the dictionary English. ostracoderms. Definitions. noun. plural of [i]ostracoderm[/i] Examples Stem. It was long thought that the first true vertebrates …
Ichthyology Lecture 3: Early Fishes Flashcards
WebDefinition the evolutionary development of a group; establishes relationships among organisms based upon derived characteristics and describes patterns of evolutionary change Term taxonomy Definition the study of the classification of organisms, including the theoretical basis for the classification Term systematics Definition WebThe Osteostraci (bony armored jawless fish) are generally considered the sister taxon of Gnathostomata. [2] [8] [9] Jaw development in vertebrates is likely a product of the supporting gill arches. This development would help push water into the mouth by the movement of the jaw, so that it would pass over the gills for gas exchange. hollinger house
Term definition three the phylum chordate is - Course Hero
WebTerm definition three the phylum chordate is. School University of Florida; Course Title BIOLOGY MISC; Uploaded By Vanadium23kristina. Pages 85 Course Hero uses AI to attempt to automatically extract content from documents to surface to you and others so you can study better, e.g., in search results, to enrich docs, and more. WebPlacodermi is a class of armoured prehistoric fish, known from fossils, which lived from the Silurian to the end of the Devonian period. Their head and thorax were covered by articulated armoured plates and the rest of the body was scaled or naked, depending on the species.Placoderms were among the first jawed fish; their jaws likely evolved from the … Webnoun os· tra· co· derm ˈä-strə-kō-ˌdərm ä-ˈstra-kə- : any of various primitive, extinct jawless fish (class Agnatha) of the Lower Paleozoic with a bony covering of plates … human power generators for game play