DetailsMonostychia australis are an extinct genus of echinoid which come from Murbko, Austrlia. These particular species are well known for their flat disc shaped bodies. The fossils have been professionally cleaned and prepped so are free of matrix. They were found in the Glenforslan formation, from the Miocene period making them 23 -5 million years old. Each specimen is approx 2.5 cm in size and comes supplied in a packet with an information label.