I am a quarry geologist in PA and rarely need to identify fossils. However, I found this cool one that I just can't ID from publications if google searches. It was found in a quarry near Pottsville and St. Clair, PA. It is from the base of the Llewellyn Formation. I found some photos of fossils that look similar but usually each "scale" (not sure of the proper term) is more like an inch, but as you can see by the penny in the picture these are much smaller. Help!