Discovery of a Late-Ediacaran Crown-Group Sponge Fossil Challenges the Conventional View of Sponge Evolution

The discovery of the late-Ediacaran fossil Helicolocellus cantori, a large, stemmed benthic organism with an organic skeleton similar to hexactinellid sponges, challenges the prevailing view that sponge fossils only appear in the Cambrian period and suggests sponges diverged and existed in the Precambrian as non-biomineralizing animals.