Phragmodictya jinshaensis sp. nov., a hexactinellid dictyosponge from the Cambrian of Jinsha, south China

A new fossil species from Cambrian strata of Jinsha, south China, is interpreted as the earliest known hexactinellid dictyosponge. Phragmodictya jinshaensis sp. nov. occurs within the Niutitang Biota, the oldest known Burgess Shale-type biota. The new species is characterized by a convex, disc-shaped body consisting of reticular skeletal network surrounded by frill-bearing radial ridges. The discovery of this sponge is unexpected and provides additional evidence bearing on the nature of Precambrian sponges and the early evolution of hexactinellid dictyosponges. It also invites re-evaluation of the taxonomy of both Ediacaran and Phanerozoic sponges.