known genera of the distinctive Redlichiina family Emuellidae, known for possessing the greatest number of thoracic segments known for Trilobita as a whole (a record of 103 in one Balcoracania specimen), and so far entirely restricted to Australia and Antarctica.

The sedimentary depositional environment of the majority of Burgess-Shale-type assemblages is outer shelf, deeper water. The Emu Bay Shale in