The Emu Bay Shale

On Kangaroo Island in South Australia, the shale at Emu Bay is the only Burgess Shale-type fossil bed known in Australia, keeping soft-bodied Cambrian animals alongside the trilobites: more than 50 species, from radiodonts and worms to sponges and an early chelicerate. It holds some of the oldest phosphatised muscle tissue known, and trilobites of a family found only in Australia and Antarctica, one specimen of which has 103 body segments, the record for any trilobite. In 2011 researchers described large fossil compound eyes from an inland quarry here, including the first well-preserved eyes of Anomalocaris, with more than 24,000 lenses, a resolution rivalled today only by the dragonfly, which showed that sharp arthropod eyes evolved before jointed legs or hard shells. The rock is coarser than the Burgess Shale, so the detail is lower, but it formed in a shallow inshore basin rather than deep water, which shows soft-tissue preservation happened in a range of Cambrian settings.