Pentremites australis sp nov., a new Lower Carboniferous (Tournaisian) blastoid from New South Wales

A new species of the blastoid Pentremites Say is described from the Lower Carboniferous Brushy Hill Limestone Member (middle Tournaisian) at Glenbawn Dam, New South Wales. Pentremites australis sp. nov. has a small pyriform (obconical) theca strongly pentagonal in plan view, with high pelvis and truncate vault. The anispiracle is excavated in an apparently undivided anal deltoid plate. its short deltoids are barely visible and lancets are exposed full width forming petaloid ambulacra on the summit. Side plates abut the lancet and one hydrospire pore is present per side plate. Stratigraphically, P. australis is the earliest member of the genus, otherwise known from Mississippian (late Tournaisian) to Lower Pennsylvanian sequences of North and South America. The theca of the new species exhibits a combination of primitive and derived features.