Jamoytius kerwoodi

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Jamoytius kerwoodi
Fossil range: Silurian

Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Hyperoartia or Anaspida
Genus: Jamoytius
Species: Jamoytius kerwoodi
White 1946[1]

Jamoytius kerwoodi was a species of primitive, eel-like jawless fish that lived in the Silurian period.

J. kerwoodi is the earliest known anaspid.[2]. It had long, paired fins running along its body - making it a good swimmer. J. kerwoodi resembled a lamprey, especially with its rounded mouth and elongated body. However, as it had no teeth or teeth-like structures in its mouth, it was not carnivorous like its distant modern-day relative, the lamprey. It was more likely to have been a filter-feeder or a detrius-feeder, possibly in the manner of larval lampreys.

The fish had a cartilaginous skeleton, and a branchial basket resembling the cyclostomes - used to suggest that it was a near-ancestor to that clade.[3] It also possessed weakly mineralised scales.[4]

[edit] Further reading

Long, John A. The Rise of Fishes: 500 Million Years of Evolution Baltimore: The Johns Hopkins University Press, 1996. ISBN 0-8018-5438-5

[edit] Links to images

[edit] References

  1. ^ White, E.I. (1946). "Jamoytius kerwoodi, a new chordate from the Silurian of Lanarkshire [Scotland]". Geological Magazine 83 (2): 89–97. 
  2. ^ New Page 4
  3. ^ Ritchie, A. (1968). "New evidence on Jamoytius kerwoodi White, an important ostracoderm from the Silurian of Lanarkshire, Scotland". Palaeontology 11: 21–39. 
  4. ^ Today, G. (2003). "Fossils explained 43: Anaspid fishes". Geology Today 19 (3): 111–113. doi:10.1046/j.1365-2451.2003.00413.x.