Large Anaspid Fossil Jawless Fish from Silurian of Scotland

Description: The Anaspids were simple dorso-laterally compressed fish that probably led a bottom-dwelling existence. Their main common feature was a jawless mouth. Indeed the name means without jaws. They were mostly quite small fishes that flourished during the Silurian and Devonian that then became extinct except for their modern-day relatives the Lampreys and Hagfishes. The gills opened as a row of holes along the side of the animal, typically numbering from 6-15. One unusual example from Canada holds the record for gills at 30 pairs! They probably behaved much like the lampreys, and most lived in freshwater environments. This fine example is known as Lasanius. It had an elaborate array of dorsal scales a number of which which are seen here. Complete examples of the Anaspida are quite rare, with few ever available to the general public. What is seen here is some of the dorsal spines and the branchial arches of what must have been a truly enormous example. I have included a photograph of a near-complete Lasanius of normal proportions for comparison. A Goliath among Davids, indeed!

Also see: Paleozoic Fish Fossils