Streptaster vorticellatus
Edrioasteroids are rare, beautiful, and popular
fossils to collectors and professional paleontologists. They show their
affinities with other echinoderms in having obvious pentaradial symmetry
(structures repeat in a circle 5 times).
Here’s a perfect Streptaster vorticellatus
(Hall, 1866) edrioasteroid from the Cincinnatian outcrop belt of northern
Kentucky, USA. It is encrusting a hardground (the same hardground horizon
that has produced abundant specimens of the hyper-rare edrio. Carneyella
ulrichi).
Classification: Animalia, Echinodermata, Echinozoa, Edrioasteroidea,
Hemicystitidae
Stratigraphy: ~6 to 7 meters above base of Bellevue Formation (part of the “Grant
Lake Formation”), Maysvillian Stage, middle Cincinnatian Series, middle Upper
Ordovician
Locality:
southern end of larger Maysville West roadcut (western side), northern Mason
County, Kentucky, USA
Streptaster vorticellatus (13 mm across) from the Bellevue Formation (Upper
Ordovician) at the Maysville West roadcut of northern Kentucky, USA.