Early Burrowers

摘要

Direct fossil evidence of animals from Edia-caran period-the time in Earth's history just before extensive animal diversification in the Cambrian-is scant. However, the remains of animal activity in sediment, which remain intact through geologic time can provide clues about animal behavior and evolution. Pecoits et al. (p. 1693; see the Perspective by Droser and Gehling) found a suite of fossil animal burrows in sedimentary rocks in Uruguay.