Saturday, January 15, 2011

Platycerid snails from the Silica Shale

Few snails are as well known in the Devonian as Platyceras is. The name sounds similar to that of an Ammonite since they share a similarly pronounced last part of their names. While they are both Mollusks, Platyceras is a Gastropod (or stomach foot) wile Ammonites are Cephalopods (head foot).

Platyceras is a very prolific genera within the Silurian to Devonian and is known to exist from the Late Ordovician (Sandbian - 460 mya) through the Permian (Capitanian - 260 mya). Within the Silica Shale they can grow to be quite large and I've found a couple of species:

Platyceras bucculentum (Hall 1862) - Note the undulating, wide, bell like margin. This species often has a well defined crest but this specimen is lacking that.

Another Platyceras bucculentum

This specimen appears to be a Platyceras rarispinum based on the spine bases present on the shell.

All ID's are based on the 1975 book by Robert V. Kesling & Ruth B. Chilman: Strata and Megafossils of the Middle Devonian Silica Formation: Museum of Paleontology, Papers on Paleontology, No. 8, pg. 117, pl. 19,20.

1 comment:

  1. Do you have Twitter or some other means that people can contact you? I live near multiple good cross-sections which include the Mahantango Fm. in West Virginia but didn't see a means to email you or anything.