Primitive Jawless Fish Tremataspis

Tremataspis mammillata

Class Osteostraci, Cephalaspidiformes, Tremataspidae

Geological Time: Upper Silurian, Middle Ludlovian Stage

Size: Fossil is 30 mm by 23 mm

Fossil Site: Island of Oesel, Estonia

Tremataspis mammilataThe Osteostracii are a primitive group of jawless fish. This one is known as Tremataspis and comes from the Silurian of Estonia. It had a rounded shield that covered most of the body and was presumed to have aided the fish in plowing through the substrate in search of food. Notice the perfect centrally-located eye holes, single nostril , sensory fields and ornamentation in the more complete example. The shield was one solid piece, and as such most likely did not grow as the animal aged. Presumably the larvae had no such protection, growing a shield only once they had reached the mature stage.

Also see: Paleozoic Fish Fossils Tremataspis schmidti

click to enlarge fossil pictures

Additional Tremataspis mammillata specimens for Comparison
Tremataspis mammillata

l Fossil Mall Home l Fossils Science Section l

l Paleontology & Fossils l Paleobiology and Geologic Timeline l
l Fossil Amber l Ammonite Fossils l Dinosaur and Reptile Fossils l Fossil Kits l
l Crinoids and Echinoderms l Fish Fossils l Fossil Dealers l Insect Fossils l Invertebrate Fossils l
l Plant Fossils l Stromatolites l Trace & Ichnofossils l Trilobite Fossils l Vertebrate Fossils l