Tuesday, July 22, 2014

Large Crinoid stems from the Onondoga Formation

This past May I visited an old quarry south of Syracuse, NY that exposed part of the Onondoga formation (middle Devonian, Eifelian stage). The floor of the quarry exposed part of a Biostrome (an area that surrounds a reef but is not the reef itself) that is contained within the Edgecliff member. One particular layer was chock full of large diameter, stoloniferous crinoid stems.

Specimen #1 (reassembled)

Specimen #2 (reassembled)

In places the stems seemed to be the substrate upon which everything else resided. For example, this Fistuliporid bryozoan....

.... and the base of fenestellid type bryozoan.

There is a paper called "STRATIGRAPHY OF THE ONONDAGA LIMESTONE (DEVONIAN) IN CENTRAL NEW YORK By William A. Oliver, Jr (Bulletin of the Geological Society of America VOL. 66. PP. 621-662. JULY 1954)" that has been helpful in identifying some of the fossils I found, but there is not much info for Bryozoans.

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