Boreaspis

Boreaspis
Temporal range: Pragian–Emsian
Scientific classification
Kingdom:Animalia
Phylum:Chordata
Class:†Osteostraci
Order:†Benneviaspidida
Family:†Boreaspididae
Genus:†Boreaspis
Stensio, 1927
Species
  • B. rostrata Stensio, 1927 (type)
  • B. batoides Wangsjo, 1952
  • B. macrorhynchus Wangsjo, 1952
  • B. puella Wangsjo, 1952
  • B. spinicornis Wangsjo, 1952
  • B. triangularis Wangsjo, 1952
  • "B." ceratops Wangsjo, 1952
  • "B." intermedia Wangsjo, 1952

Boreaspis (meaning "Boreas' Shield") is an extinct genus of osteostracan agnathan vertebrate that lived in the Devonian period.

Fourteen different species of Boreaspis have been found in sandstone of the lagoons and estuaries of Devonian Spitsbergen; however, some of these likely do not belong to the genus.[1] The species B. robusta and B. costata have been reassigned to Spatulaspis; and B. circinus, B. curtirostris, and B. gracilis now belong to Dicranaspis.[2]

Species of Boreaspis were very small, with head shields about 2 centimetres (0.79 in) long.[3] All species possessed a long spathe-like rostrum derived from the anterior-most end of the head shield, which would have enhanced the fish's hydrodynamics and was probably also used to root out food buried beneath the substrate.[4]

References

  1. ↑ Sansom, R.S. (2009). "Phylogeny, classification and character polarity of the Osteostraci (Vertebrata)". Journal of Systematic Palaeontology. 7 (1): 95–115. doi:10.1017/S1477201908002551.
  2. ↑ Groh, S. "Appendix". Patterns of diversification in osteostracan evolution (PDF) (M.S.). Uppsala University.
  3. ↑ Frickhinger, Karl Albert (1995). Fossil Atlas: Fishes. Trans. Dr. R.P.S. Jefferies. Blacksburg, Virginia: Tetra Press.
  4. ↑ Palmer, D., ed. (1999). The Marshall Illustrated Encyclopedia of Dinosaurs and Prehistoric Animals. London: Marshall Editions. p. 25. ISBN 1-84028-152-9.
  • Long, John A. (1996). The Rise of Fishes: 500 Million Years of Evolution. Baltimore: The Johns Hopkins University Press. ISBN 0-8018-5438-5.


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