Megistaspis triangularis Unusual Russian Lower Ordovician Trilobite

Description: A well-inflated example of an ancient member of the Asaphidae, this is Megistaspis triangularis. It is easy to see the derivation of the species name from the triangular, fusiform shape of this particular example of the genus. One of some 20 members of the genus, notice the distinguishing pygidial spine, reminiscent of the younger genus Huntonia from the Devonian of Oklahoma. It is thought that the low profile allowed the trilobite to conceal itself just below the surface of the seafloor.