Praecambridium


Praecambridium sigillum is an extinct organism that superficially resembles a segmented trilobite-like arthropod. It was originally described as being a trilobite-like arthropod, though the majority of experts now place it within the Proarticulata as a close relative of the much larger Yorgia. It is from the Late Ediacaran deposit of Ediacara Hills, Australia, about 555 million years ago. On average, P. sigillum had at least 5 pairs of segments, with each unit becoming progressively larger as they approach the cephalon-like head.

Etymology

The generic name is a compound word, with the Latin prefix prae "before" and a reference to the Cambrian mollusc genus Cambridium, in reference to how the appearance of the various segments are reminiscent of the muscle-scars on the inner surface of the shells of Cambridium. The specific name is from Latin sigillum "a sigil".