Topic: Platteville Oncocerid Nautiloids: Living on the Mohawkian Sea Floor
Presenter: John Catalani

Although many Ordovician nautiloid faunas are dominated by straight-shelled orthoconic forms, this is not true for the incredibly abundant and diverse Platteville fauna. The Platteville nautiloid fauna consists of 9+ Orders with the Oncocerida accounting for 50+% of the published species. I will analyze the environment and paleogeography of the Mohawkian Sea, home of the Platteville fauna. Faunal lists illustrate the classification of the Platteville nautiloid fauna and place the oncocerids in context. Comparison of the Oncocerida with the other Platteville nautiloid orders will illustrate the make-up of the fauna. The morphology and paleoecology of the oncocerids will be addressed followed by a listing and description, with photographs, of the major genera and species.