Early Cambrian (Eoredlichia Zone)
Yu’ anshan Member., Qiongzhusi Formation
Chengjiang, China

Fine 1.1cm priapulid coiled in matrix.

Circocosmia is a genus of worm that has been assigned to the Phylum Priapulida but some paleontologists have questioned that and described it as just priapulid-like.  It appears it lived only during the Early Cambrian.

We think of all worms belonging to the same group but the word “worm” is actually a catch-all for a diverse mix of animals representing more than one phylum – more than one ancestry.  Some worms have had jaws or armor (composed of sclerites) but most haven’t so they appear in the fossil record only where other soft-bodied organisms are preserved.