Arumberia and other Ediacaran–Cambrian fossils of central Australia

ABSTRACT

Problematic fossils are described from Late Ediacaran to Early Cambrian red sandstones of the Arumbera Sandstone, Grant Bluff, and Central Mount Stuart Formations in central Australia, within a new systematic classification of Vendobionta. Arumberia banksi has been one of the most problematic of Ediacaran fossils, at first considered a fossil and then a sedimentary or organo-sedimentary structure. Our re-examination of the type material and collection of new material reveals misconceptions about its topology: it was a recessive fossil on the bed top, protruding down from the counterpart overlying slab. The concave-up body was 3 mm thick and chambered above a diffuse lower surface, so not a sedimentary structure. Also re-evaluated is the discoid fossil Hallidaya brueri, here including “Skinnera brooksi’ as its upper surface. A new species (Noffkarkys storaaslii gen. et sp. nov.) is a multilobed frond with regular, fine, trapezoidal quilts. Three new records of Trepassia wardae, Dickinsonia costata, and Ernietta plateauensis are reported from the Arumbera and Grant Bluff Formations. Reevaluation of palaeomagnetic and biostratigraphic data suggest an hiatus of 26 million years at the Ediacaran–Cambrian boundary within the Arumbera Formation, but some of this missing time is filled by the Grant Bluff and Central Mount Stuart Formations.

KEYWORDS:

• Arumberia
• Ediacaran
• Vendobionta
• Central Australia
• problematica

Acknowledgments

John Laurie provided access to holotype material of Arumberia banksi in collections of Geoscience Australia, in Canberra. Max Heckenberg retrieved core for examination at the Northern Territory Department of Resources Core Facilities in Alice Springs. Patrick and Cary Brown allowed access to the Valley Dam locality on their property. Will Defliese helped during fieldwork. Malcolm Walter, Christina Edgoose, Bruce Runnegar, Shuhai Xiao, Natalia Bykova, and Dima Grazhdankin offered useful discussion. Reviews by Alexander Liu, Soren Jensen, and Santosh Pandey greatly improved this manuscript.

Disclosure statement

No potential conflict of interest was reported by the authors.