Rare Emuella Trilobite from Emu Bay Australia

This specimen is an example of the rarely-seen trilobite Emuella polymera from Kangaroo Island, Australia. The Emu Bay Shale is Australia’s only Burgess Shale type deposit. It has fauna in common with both the younger Burgess Shale and the slightly older Chengjiang Biota. That formation overlies the White Point Conglomerate; as a consequence the White Point is slightly older. Unlike the Burgess Shale and Chengjiang Biota, however, the Emu Bay Shale deposits were a shallow water depositional environment. The genus is the patronym of the family Emuellidae, and the genus refers to the many body segments. Like Bolacorcania this one added segments ahead of the pygidium as it grew. This one is a negative example of a juvenile.