Possible animal body fossils from the Late Neoproterozoic interglacial successions in the Kimberley region, northwestern Australia

New specimens of the enigmatic Ediacara-type fossil Palaeopascichnus have been identified from the upper part of the Neoproterozoic Ranford Formation in the Kimberley region, northwest Australia. New material is morphologically similar to Palaeopascichnus and represents the largest species of this genus. They resemble the present-day xenophyophore protists in chamber morphology and growth patterns, supporting the interpretation that Palaeopascichnus is possibly a xenophyophore body fossil rather than a trace fossil. Stratigraphic correlation reveals that the new Palaeopascichnus specimens are preserved in the interglacial successions between the Landrigan/Marinoan and Egan/Ediacaran glaciations. If correlation with the early Ediacaran formations of South Australia is accepted, this represents the earliest known identifiable member of the Ediacara biota. New fossil record fills the evolutionary gap between the Cryogenian and Ediacaran animal assemblages and well-known Ediacaran biota. The new Palaeopascichnus specimens represent the first record of Ediacara-type fossils in Kimberley, and suggest the probability that additional Ediacaran fossils may be found in northwestern Australia.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideResearch Highlights► Late Neoproterozoic Palaeopascichnus recorded from the Kimberley region, northwestern Australia. ► The first Ediacaca-type fossil in Western Australia. ► The possibly oldest Ediacara-type body fossil predating Gaskiers glaciations.