Middle Cambrian
Coulouma Formation
Montagnes Noire, France
Excellent 1.9cm carpoid
Carpoid,

Trochocystites is a genus of carpoid known from the Cambrian of Europe.  Carpoids are an extinct group that most paleontologists consider to be early echinoderms while others consider the possibility that they could be primitive chordates.

This specimen comes from a time early in the history of the group.  They died out during the Devonian Period (known from the Bundenbach locality in Germany).