Here is amazing specimen, the uncommon spiny Illaenid trilobite species

 - Illaenus tauricornis Kutorga, 1848

The offering taxon is the big  (8cm) example showing amazing preservation of its caramel colored shell. The trilobite has a rare for Illaenids stretched position without any deformation and providing  realy "holotype" display of the species. 

The specimen was found in the Middle Ordovician (Darriwilian), Aseri stage deposits of Vilpovitsy quarry, St Petersburg region, Russia. Reconstruction 5-6%. Shipping worldwide $35.