Heterostraci

Thesaurus

Noun

Heterostraci - extinct group of armored jawless fishes or fish-like vertebrate; taxonomy is not clearsuborder Heterostracianimal order - the order of animalsorder Ostracodermi, Ostracodermi - extinct group of armored jawless vertebrates; taxonomy is not clearheterostracan - extinct jawless fish with the anterior part of the body covered with bony plates; of the Silurian and Devonian

Heterostraci

[‚hed·ə′räs·trə‚sī] (paleontology) An extinct group of ostracoderms, or armored, jawless vertebrates; armor consisted of bone lacking cavities for bone cells.

Heterostraci

a subclass of agnathous fossil vertebrates. Heterostraci were common during the Paleozoic era, from the Ordovician to the end of the Devonian. The shell was made of a varying number of schistoid plates of acellular bone, with a single (caudal) fin, lateral apophyses serving as supporting planes, and dorsal ridges, or spines, for the maintenance of equilibrium. The length of Heterostraci ranged approximately from several cm to 1 m. They inhabited both ocean and fresh waters, feeding on small organisms of the benthic and middle depths. Heterostraci are of great significance in the comparison of continental and marine deposits of the Middle Paleozoic.

REFERENCE

Obruchev, D. V. “Vetv’ Agnatha: Bescheliustnye.” In Osnovy paleontologii: Bescheliustnye, ryby. Moscow, 1964.

D. V. OBRUCHEV

Heterostraci

Heterostraci

Heterostraci

Heterostraci

REFERENCE

Heterostraci

Synonyms for Heterostraci

noun extinct group of armored jawless fishes or fish-like vertebrate

Synonyms

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