What is "gravicalymene"

Gravicalymene is a genus of trilobites from the order Phacopida, suborder Calymenia. Gravicalymene has been a 'hot button' trilobite lately. The species that are currently in this genus have been in Calymene and Sthenocalymene. One thing that seems to be consistent with the genus Gravicalymene is that they sometimes occur in Dolomitic limestone and that many occur in the Silurian age.

The most rare example of the genus is the Middle Ordovician species Gravicalymene magnotuberculata. This species is also amongst the rarest of all Calymenidae and is regionally confined to one or two exposures in New York State. G. magnotuberculata is noted for its extremely pustulose exoskeleton, bell shaped glabella and lack of complete articulated specimens.