Heterostraci

Heterostraci
Temporal range: Wenlock[1]–Late Devonian, 433–359 Ma
Panamintaspis
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Infraphylum: Agnatha
Class: †Pteraspidomorphi
Subclass: †Heterostraci
Lankester 1868
Orders
Among the most primitive heterostracans are tolypelepids (top right). Most heterostracans are pteraspidiforms, such as the pteraspidids (bottom right), doryaspidids (bottom left) and the huge psammosteids (top left), which are the youngest known members of the group.[2]

Heterostraci (Ancient Greek, ἕτερος+ὄστρακον "those [with] a different shell" [-i is pl. of -us]) is an extinct subclass of pteraspidomorph, Ostracoderm, jawless vertebrate that lived primarily in marine and estuary environments. Heterostraci existed from the mid-Ordovician to the conclusion of the Devonian.

  1. ^ Sansom, Robert S.; Randle, Emma; Donoghue, Philip C. J. (February 7, 2015). "Discriminating signal from noise in the fossil record of early vertebrates reveals cryptic evolutionary history". Proceedings of the Royal Society B. 282 (1800): 20142245. doi:10.1098/rspb.2014.2245. PMC 4298210. PMID 25520359.
  2. ^ Janvier, Philippe (1997) Heterostraci The Tree of Life Web Project.