Monday, October 18, 2010
October 18, 2010 : Jamoytius kerwoodi (Extinct)
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.