Monday, October 18, 2010

October 18, 2010 : Jamoytius kerwoodi (Extinct)

Jamoytius kerwoodi

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

J. kerwoodi is the earliest known anaspid.. 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. It is also the earliest known vertebrate with camera-type eyes. It also possessed weakly mineralised scales.

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