Name:
Strobilocystites calvini Age: Devonian Formation: Cedar Valley Formation Location: Linn County, Iowa Size: Cystoid is 0.9 inches across This specimen is not for sale Click here for similar specimens that are for sale
Here is a scarce cystoid. This specimen is Strobilocystites calvini from the Devonian of Iowa. This is one of the youngest cystoids known to exist. These primitive echinoderms are usually found in Ordovician and Silurian rocks - very few are found in Devonian age layers - and none are found in younger sediments. This specimen is very 3-dimensional and exhibits fine detail. The plate structure is very good. One of the large pore-rhombs is beautifully displayed and the ambulacra are visible. The white cystoid contrasts well with the yellowish-gray matrix that is loaded with other fossils. This is a fine example of this unusual echinoderm.