Birkenia Anaspid Fish Fossil with with Rare Organ Preservation

part and counterpart from the Silurian of Scotland

Birkenia elegans

Class Agnatha, Order Anaspidiformes

Geological Time: Upper Silurian

Size: Fish fossil is 55 mm in length by 22 mm high on a 42 mm by 39 mm matrix

Fossil Site: Leshmagow, Scotland

Fossil Code: UKF230

Price: Sold


Birkenia Anaspid Fish FossilDescription: 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, Birkenia Jawless fish arttypically 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 Birkenia. It had an elaborate array of dorsal scales, not visible in this dorsal example. This one is quite rare in that it displays features that appear to be eyes. They are actually posterior to the eyes which would be on the sides of the body and are known as the otic capsules. An otic capsule, also known as the bony labyrinth, is the bone surrounding the organs of balance. This is the first such example I have come across. Any specimen of the ansapids is highly prized, so one displaying this much detail will surely be a trophy piece for any collection. See my other offerings for an unusual part/counterpart specimen.

Also see: Paleozoic Fish Fossils

Fish Fossils for Sale

click to enlarge

 


Fossil Mall Home
l Museum and Rare Fossils l The Fossil Dealers l
Fossil Categories:
l Ammonites for Sale l Trilobites for Sale l Fish Fossils for Sale l
l Insect Fossils l Invertebrate Fossils l Plant Fossils l Stromatolites l
l Crinoids and Echinoderms Fossils l Dinosaur Fossils l Fossil Amber l