Asaphus expansus Russian trilobites

Asaphus expansus is one of the older trilobites of the asaphus series from the Saint Petersburg region of Russia. Coming from the Lower Ordovician Kunda layer, expansus is believed to be the progenitor of a large majority of the more than 30 Russian Asaphids, including Asaphus kowalewskii, the species with the astonishingly long eye stalks. This scarcer of the Russian Asaphid trilobites is a natural double.

Also see: Russian Trilobites Gallery Russian Asaphidae Evolution Sequence