Bajoprosopon piardi n. gen. and sp. from the Middle Jurassic of France, with a revised diagnosis of the family Prosopidae von Meyer, 1860 (Brachyura, Podotremata) and notes on the availability of names introduced by Hermann von Meyer (1835,1857)

摘要

The earliest known brachyurans, or true crabs, are of Early and Middle Jurassic age. In general, they are rare and known from either a single or a few specimens only. Here we record a new genus and species of homolodromioid crab of Bajocian (early Middle Jurassic) age from Calvados (northwest France), based on a unique dorsal car-apace. On the basis of carapace morphology, this is here assigned to the primitive fam-ily Prosopidae, but distinguished from other members due to the carapace grooves and tubercles and conspicuously large orbital fossae.