Article: A presumed spelaeogriphacean crustacean from an upper Barremian wetland (Las Hoyas; Lower Cretaceous; Central Spain)

A third fossil attributable to the crustacean peracarid order Spelaeogriphacea is described from an Upper Barremian (125 Ma) lacustrine environment in Central Spain. Neither the new taxon, Spinogriphus ibericus gen. et sp. nov., nor the two already described fossil forms can be identified with certainty as crown-group spelaeogriphaceans. We consider that Schram’s 1974 family Acadiocarididae represents stem-lineage spelaeogriphaceans and should accommodate these fossil taxa that display very generalised peracaridan features and lack any conspicuous autapomorphies, except for a short carapace, undifferentiated pereiopods, foliaceous pleopods and a tail fan-like (uropods + telson) caudal structure where the unsegmented uropodal endopod lacks annulation. The zoogeography of the Acadiocarididae is Laurasian in contrast to the modern, crown-group spelaeogriphaceans (Spelaeogriphidae), which are limited to Gondwanan territories.