Asaphus kowalewski Russian Ordovician Trilobite

Description: A well-inflated example of a high-eyestalked member of the Asaphidae, this is Asaphus kowalewski. The region in which these trilobites lived was subject to dramatic changes in salinity and turbidity, and the trilobites were able to make rapid (geologically speaking) evolutionary adjustments. These adjustments were thought to be able to allow them to see both predator and prey more easily. The 20 mm eyestalks on this specimen would have served it well. It is shown with a partial cystoid of the genus Echinosphaerites, an Echinoderm relative of crinoids, blastoids, and starfish.