Cambrian Explosion: very early animals (Introduction)

by David Turell , Wednesday, December 10, 2014, 15:04 (3636 days ago) @ David Turell

Not very complex. Not even bilaterally symmetrical:-http://www.sciencedaily.com/releases/2014/12/141209081644.htm-Abstract:-http://www.nature.com/srep/2014/141209/srep07340/full/srep07340.html- "N. pugio shows no trace of a gut, coelom, anterior differentiation, appendages, or internal organs that would suggest a bilateral body plan. Instead, the sac-like morphology invites comparison with the radially symmetrical chancelloriids. However, the single-element spines of N. pugio are atypical of the complex multi-element spine rosettes borne by most chancelloriids and N. pugio may signal the ancestral chancelloriid state, in which the spines had not yet fused."-Basically a sac with spines, 520 million years old