Description

Upper Ordovician (Pusgillian)
Lower Ktaoua Formation
Tizi n-Mouri, Morocco
Very large, complete 87mm carpoid on 115mm slab.

Dendrocystites is a genus of Ordovician carpoid that had been known only from North America and Europe until finds were recently reported in Morocco.

Carpoids appeared during the Cambrian but apparently died out in the Early Devonian. Scientists have been fascinated by the group once considered stem-group echinoderms and then allied with other groups because they lacked the radial symmetry of echinoderms. In fact, they lack any symmetry and can be variable in form. However, because their skeletons have the same calcite-composed, crystalline structure as echinoderms, they are classified as such.

Nice contrast against the matrix.

What is a carpoid? This article explains them (PDF)