Unusual Russian Trilobite Illaenus schmidti

Description: This is an example of the unusual trilobite Illaenus schmidti. Based upon the fact that the freestanding genal spines are neither as long, nor as widely extended, as some examples it is most likely an example of the variety cliens. The other variety, cardinalis has flaring, elongated genals. Some think these may have been an expression of sexual dimorphism. This is one of the 50-odd members of the genus, and known for the high profile of the cephalon which is thought to have aided the trilobite in plowing through the substrate in search of a meal.