User:Abyssal/Prehistory of Europe/Selected picture/8

A fossil of the trilobite Pseudoasaphus praecurrens. This specimen dates back 460 – 468 Million years ago to the Darriwilian age of the Middle Ordovician epoch and was discovered near Saint Petersburg, Russia in the Koporka River deposits. It is 18.4 x 10 x 4.4 cm in size and has a mass of about 580g. Photo credit: Didier Descouens