Middle Cambrian (Atavus Zone)
Cateena Group, Atavus/Opimus or Punctuosus Zone
Quarry on Isandula Road, S. of Gawler River, 8km S. of Ulverstone
Tasmania, Australia
8mm edrioasteroid on 75mm slab
Edrioasteroid,

Cambraster is one of the earliest-known genera of the Class Edrioasterioidea, which is one of the earliest groups of echinoderms.  So far, this genus is known only from the Cambrian of Australia.

Edrioasteroids tend to be uncommon where they occur though they can be found in groups.  They existed almost across the entire Paleozoic Era, apparently dying out around the middle of the Permian.