Archaeocyathids fed in a similar way to modern sponges, filtering plankton from the water column through pores in their sides. Their decline in the late Cambrian has been attributed to competition from more modern sponges.
The Brasier Collection contains a remarkable diversity of archaeocyathids, including the material associated with Brasier's 1976 publication Early Cambrian intergrowths of archaeocyathids, Renalcis, and pseudostromatolites from South Australia. It also contains material from other sites in Australia, Russia and Antarctica, such as hand specimens, polished rock slices, and thin sections.
In this fossil, also from the Cambrian of Australia, stromatolites have grown up between the near-circular archaeocyathids, creating bands in the sediment.