| Popis: |
Metazoa evolved in shallow water seas in the late Precambrian, and there was a concomitant increase in abundance and diversity of trace fossils that reached very high levels by the Early Cambrian. There may have been some colonization of deep water, as evidenced by the «soft-bodied» fauna at Mistaken Point, Newfoundland but it was mostly by sessile animals which left few trace fossils. Shallow water late Precambrian and Early Cambrian sequences have yielded not only shallow water trace fossils but also many examples of traces typical of later deep water deposits. Significant colonization of the deep oceans by trace making animals was, however, delayed until the Early Ordovician |
