This Specimen has been sold.
3.4" Curled Asaphus Expansus Trilobite - Russia
This is a large, 3.4" long, curled Asaphus expansus trilobite. It was collected from the Putilovo quarry in the St. Petersburg region of Russia. The caramel colored shell contrasts nicely with the light colored limestone. There is quite a bit of shell restoration on the tail and some on the last few segments.
Trilobites were a very diverse group of extinct marine arthropods. They first appeared in the fossil record in the Early Cambrian (521 million years ago) and went extinct during the Permian mass extinction (250 million years ago). They were one of the most successful of the early animals on our planet with over 25k described species, filling nearly every evolutionary niche. Due in large part to a hard exoskeleton (shell), they left a excellent fossil record.