Tuzoia Phyllocarid and Nephrolenellus Trilobite

Description: This unusual association plaque shows an example of a rarely-seen Phyllocarid known as Tuzoia Gunther with the Olenellid trilobite Nephrolenellus geniculatus. Tuzoia believed to be a bivalved crustacean, most well known for its distinctively-reticulated, spiny carapace. The genus is also known from the Burgess Shale and from Chenjiang Biota deposits of China. Those are largely distinguished by the presence and placement of spines on the carapace. Few examples of the genus are known from more than the carapace, as seen here. Note the intricate polygonal decoration to the carapace as well as the spines. The species was named after Lloyd Gunther, a member of a family whose members have made extensive contributions to the study of Cambrian life of Utah. Little in terms of soft tissue is known which hampers its exact placement to the tree of life.

Described in 1998, the trilobite is Nephrolenellus geniculatus, belonging to a genus with affinities to the better-known Olenelllus. Like Olenellus, they have a most distinctive large cephalon containing crescentic eyes, making them quite attractive to collectors. Most are only found as a preserved cephalon, making those from the famous Pioche Shale highly desirable. There are several cephala of larger Olenellids to be found on both the display side and the reverse, making for an interesting association plaque of Early Cambrian life.