Asaphus kowalewskii Russian Trilobite with Enormous Eyestalks

Description: Coming from the Middle Ordovician Asery Level deposits of the Wolchow River region near Saint Petersburg, Russia, this is an example of the trilobite Asaphus kowalewskii. The genus Asaphus underwent evolutionary adaptations to contend with turbidity within an inland sea. Asaphus kowalewskii may have lain in wait for prey while buried in the bottom sediment with only its eyestalks sticking out. Coming from an inland sea during the lower to middle Ordovician, the Russian trilobites from near Saint Petersburg, Russia participated in the Great Ordovician Radiation, which saw marine animal diversity increase three-fold more than the Cambrian Explosion. The Russian asaphid trilobites are a particularly interesting example of descent with modification.