Echinoids at Vulcan Mine

Echinoids are a class of echinoderms which includes the creatures commonly known as sea urchins, sand dollars and sea biscuits. Echinoids are found in deposits of any age in Florida. The ones found at Vulcan are from the Oligocene Suwannee Limestone and are around 30 million years old.

Top and bottom photos of Phymotaxis mansfieldi can be seen below. This beautiful sea urchin is reasonably common, but it is always a good day at the mine if you find a nice one. They can be anywhere from .5 to 2 inches across.



Top and bottom photos of Gagaria mossomi can be seen below. This urchin is less common than the Phymotaxis and tends to be smaller, but not always.



Top and bottom photos of Clypeaster rogersi can be seen below. In some places in the mine these sand dollars have been reasonably common, but in general they are not. There is probably more than one species found at Vulcan. Oligocene Clypeasters can be as small as .5 inch or as much as 4 or 5 inches across.



Top and bottom photos of Rhyncholampas gouldi can be seen below. This sea biscuit is by far the most common echinoid at Vulcan Mine, everyone finds a bucketful. They range in size from .5 inch to 2 inches across. Kinds of Rhyncholampas can be found in deposits of almost any age in Florida, but they are never as plentiful as in Suwannee Limestone.



Top and bottom photos of Schizaster americanus can be seen below. This is a type of sea biscuit that is sometimes called a "heart urchin". This species is quite rare at Vulcan. It is usually less than an inch across.



Top and bottom photos of Agassizia mossomi can be seen below. A very time sea biscuit that is also quite rare. About .5 inch across.



The photos of Clypeaster rogersi and the 1st photo of Rhynchoolampas gouldi are by Carol Peterson.
All other photos are courtesy of the Florida Museum of Natural History.
Text written by Bernie Peterson.

Thanks to Roger Portell of FLMNH for his assistance.