Myoscolex is an early animal known from the Cambrian Emu Bay Shale in South Australia.

[4][5] Myoscolex is the earliest known example of phosphotized muscle tissue, and as to which shows distinct annulation.

[7] Myoscolex as a polychaete worm was unconventional in appearance being laterally flattened body with "rods" protruding from the ventral side.

Movement would have been an undulation similar to that of Pikaia, and without the use of chaetae for propulsion, unlike other polychaetes.

The outer two layers are composed of calcium carbonate and represents the skin, rods, lateral lobes, and possibly eyes and proboscis.