Unusual Illaenus schmidti var cardinalis Russian Trilobite

Name: Illaenus schmidti var cardinalis Russian trilobite

Trilobite, Order Corynexochida, Suborder Illaenina, Family Illaenidae

Geologic Time : Middle Ordovician

Size (25.4 mm = 1 inch): 130 mm long by 80 mm wide on a 115 by 95 mm matrix

Location: Asery Horizon deposits of the Wolchow River region near Saint Petersburg, Russia

Illaenus schmidti var cardinalis Russian TrilobiteDescription: This is an example of the unusual trilobite Illaenus schmidti. Based upon the fact that the freestanding genal spines are longer and more widely extended than some examples it is most likely an example of the variety cardinalis. The other variety, cliens, has less 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. At 130 mm in length (measured along the curve), this one is near the top end in size for the taxon.

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