Immense Bathyuriscus Trilobite from Middle Cambrian of Utah

Description: Coming from the Cambrian Marjum Formation deposits of Millard County, Utah this is a fine association plaque of two trilobites of quite disparate morphology. The larger trilobite is a most uncommonly huge example of Bathyuruiscus fimbriatus. This one is easily 3X the normal size for this taxon. Even though it is missing the librigenae (a common occurrence) this is a highly desirable specimen.There is also an 8 mm example of an agnostid trilobite . The members of the Agnostida are mostly thought to have been planktonic in nature. Most are blind, and have a pygidium equal in size to the cephalon (ispopygous), making it hard to tell which end was which!