I often find bits of Metacoceras, a Coiled Cephalopod that existed between 314 million years ago until just before the Permian / Triassic Extinction event. I have been looking for complete specimens, but typically they are bisected on some sort of sediment plane within the limestone. Discovery In my local
This specimen came from eroded limestone. It was very light and fragile. The sections averaged about 2.5mm in width. Identification currently is unknown, however it does appear to be a straight shelled species. Eroded Limestone Most of the limestone exposed to the outside environment has an eroded edge. I am
Going by the fossil example shown on the Pennsylvanian Atlas of Ancient Life, I am calling this find a Pseudorthoceras. The rock was split into two pieces, and the photo is of them joined back up. The white markings are from an air scribe. Pseudorthoceras belongs to the class Cephalopoda.
Pseudorthoceras was first described by G. H. Girty in 1912. It was part of a paper describing new species of Pennsylvanian fossils from the Wewoka Formation of Oklahoma. The species appeared 376 million years ago and disappeared during the Permian–Triassic extinction event, 252 million years ago. This extinction, known as