Ostracods (crustacea) with Soft Part Preservation from Miocene Cave Deposits of the Riversleigh World Heritage Area, Nw Queensland, Australia

In an extensive ostracod assemblage recovered from the Bitesantennary Site, an Early Miocene (23-16 Ma) cave deposit within the Riversleigh World Heritage Area in north-west Queensland, Australia, 26 specimens were found to have soft part preservation. This is the first known example of soft part preservation in ostracods that were living in a palaeo-subterranean habitat. These exceptionally preserved specimens represent three new species, described herein: Heterocypris collaris sp. nov., Candonocypris fimibolus sp. nov. and Newnhamia mckenziana sp. nov. The appendages of a few of the specimens showed a highly detailed mode of preservation, typical of mineralization by Ca-phosphate (apatite). This preservation can be ascribed to an elevated supply of phosphate from guano derived from bats living in the cave. Two specimens feature an extraordinary mineral surface precipitation, partly embedding surface structures, such as fines setules on setae. After the decay or mechanical loss of the latter, only sharp imprints are left. Another specimen is characterized by a differential preservation of the ovaries and hepatopancreases, visible from outside the carapace as differences in coloration, a first in ostracod fossil preservation.