Blastulospongia polytreta n. sp., an enigmatic organism from the Lower Cambrian of Hubei, China

Blastulospongia is an enigmatic siliceous fossil with affinities proposed amongst both the sphinctozoan-grade sponges and radiolarians. Blastulospongia polytreta n. sp. extends the record of this genus into the Lower Cambrian (Shuijingtuo Formation) and represents its first occurrence in China (Taishanmiao section, Hubei Province). It differs from previously described species in size and pore spacing. The first evidence for benthic attachment is presented. A relationship with sphinctozoan-grade sponges is considered unlikely, but firm support for a place in the radiolarians is lacking.