When the worm turned: Concordance of Early Cambrian ichnofabric and trace-fossil record in siliciclastic rocks of South Australia

Studies of sedimentary fabrics and trace fossils across the Precambrian-Cambrian interval in South Australia demonstrate that the appearance of Treptichnus pedum, which defines the base of the Cambrian, also marks the initial development of preservable infaunal activity. There is a significant shift in the amount and nature of bioturbation at this time. These results support the broad-scale utility of T. pedum as the indicator of the base of the Cambrian.