DICTONEMA gracilis Rochester Shale Graptolite


1 in stock


Graptolites are creatures that little is still known about them. It is surmised that they were probably suspension feeders. They would have fed by straining plankton and other pieces of food from the water. Like their living relatives (animals called pterobranchs), they probably used tiny hairs (cilia) attached to a tentacle to grab food.

Graptolites are tiny, extinct animals that lived together in groups or colonies and shared the same skeleton. Each animal built its own living chamber, and these were stuck together to make the colony. Some colonies grew like branches of a tree, with many living chambers on each branch. Different kinds of graptolite colonies had branches with different shapes. They could be straight, curved or even spiral-shaped.

These Graptolites come from the Rochester Shale and the famous Caleb’s Quarry in Middleport New York. This quarry site has produced a very unique snapshot of the ancient Silurian Sea that once covered much of New York State. This formation was first discovered during the digging of the Erie Canal. The fauna has been researched recently and several books have been published on the finds from this site.

The Black Graptolite is 3 3/4 inches long by 3 inches wide sitting on an irregular gray matrix that is 4 1/2 inches by 4 1/4 inches. The graptolite has very long thin branches on a cream colored matrix from the bryozoan zone. It has exceptional branching segments.

This is the specimen you will receive.

DICTONEMA gracilis
Silurian Period
Rochester Shale
Caleb’s Quarry
Middleport, New York