Hemicyclaspis (lit.'half-round shield' or 'semicircle plate') is an extinct genus of primitive jawless fish, closely related to Cephalaspis, that lived in the Late Silurian (Pridoli)[1] to Devonian period in what is now Europe and North America. A typical cephalaspid, Hemicyclaspis had a heavily armored, shovel-shaped headshield. It is thought to have been a better swimmer than most of its relatives because of its powerful tail, stabilizing dorsal fin and the keel-shaped hydrodynamic edges of its head shield. Hemicyclaspis probably foraged the ocean floor for food.[2]

Hemicyclaspis
Temporal range: Pridoli–Early Devonian
H. murchisoni and Thyestes
Life reconstruction.
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Osteostraci
Order: Atelaspidiformes
Family: Ateleaspididae
Genus: Hemicyclaspis

Hemicyclaspis grew to a length of 5 inches (13 centimeters) and would most likely have fed on particles from the muddy sea bed.

H. murchisoni cast. Collected from Ledbury, Herefordshire, England.
1953 plaster reconstruction.

References

edit
  • Parker, Steve. Dinosaurus: the complete guide to dinosaurs. Firefly Books Inc, 2003. Pg. 58
  1. ^ Blieck, Alain; Elliott, David K. (2017-06-01). "Pteraspidomorphs (Vertebrata), the Old Red Sandstone, and the special case of the Brecon Beacons National Park, Wales, U.K." Proceedings of the Geologists' Association. 128 (3): 438–446. doi:10.1016/j.pgeola.2016.07.003. ISSN 0016-7878.
  2. ^ Palmer, D., ed. (1999). The Marshall Illustrated Encyclopedia of Dinosaurs and Prehistoric Animals. London: Marshall Editions. p. 25. ISBN 1-84028-152-9.