High Quality Content by WIKIPEDIA articles! Praecambridium sigillum ("Sigil of the Precambrian") resembles a segmented trilobite-like arthropod, though many experts place it within the proarticulatan family Dickinsoniidae. It is from either the Late Precambrian or Lower Cambrian of Ediacara Hills, Australia, about 590 to 530 million years ago. This beast is known from 13 specimens. On average, P. sigillum had at least 5 segments, each becoming progressively larger as they approach the cephalon.