Two Stalk-Eyed, Asaphus Punctatus Trilobites - Russia
This is an association of stalk-eyed trilobites of the species. Asaphus punctatus. They come from the Gostlitsy Quarry in the St. Petersburg region of Russia. These have been prepared so that they look ready to crawl off the rock. The complete trilobite measures 1.9" long and the incomplete specimen is 1.7" long. No restoration on either trilobite.
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 currently described species, filling nearly every evolutionary niche. Due in large part to a hard exoskeleton (shell), they left an excellent fossil record.