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-Cam brian interval in South Australia demonstrate that the appearance of Trepti chnus 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 suppo rt the broad-scale utility of T. pedum as the indictor of the base of the C ambrian.