Silurian hexactinellid sponges from northern British Columbia, Canada

Abstract

Faunules of largely hexactinellid sponges have been collected from siltstones of Early Silurian Wenlock or latest Landovery age within the upper Road River Group from northern British Columbia. The assemblages include the new species: Protospongia columbiana, Hexatractiella pseudonevadensis and Cyathophycus akiensis. Other taxa described include the hexactinellids Protospongia conica Rigby and Harris, 1979, Hexatractiella nevadensis (Rigby and Stuart, 1988), Diagoniella sp., Gabelia pedunculus? Rigby and Murphy, 1983, and a specimen of the monaxonid demosponge Wareiella typicala Rigby and Harris, 1979. Also included is a fragment of what must have been a steeply obconical-cylindrical hexactinellid sponge of uncertain taxonomy; it has a skeleton of robust hexactines in an unquadruled net, above a root-tuft of 10-20 spicules. Other sponge impressions include small circular clusters of hexactines with radiating, to basketlike patterns and somewhat similar, isolated and dissociated, long probably roof tuft spicules and possible basal root tuft rosettes of monaxons. The faunules are similar to other outer continental margin, black shale, sponge assemblages of the Early Paleozoic Era, and include elements previously described from northern British Columbia and central Nevada.