Cason Shale
The Cason Shale is a Late Ordovician to Middle Silurian geologic formation in the Ozark Plateaus of Arkansas. The name was introduced in 1894 by Henry Shaler Williams in his study of Arkansas. Williams designated a type locality at what was known as the Cason tract and mine, near Batesville, Independence County, Arkansas, however, he did not assign a stratotype. As of 2017, a reference section has not been designated for this unit.Paleofauna
- Acodus
- Ambalodus
- Amorphognatus
- Belodella
- Belodina
- Carniodus
- Cordylodus
- Distacodus
- Distomodus
- Drepanodus
- Eoligonodina
- Hadrognathus
- Hindeodella
- Keislognathus
- Ligonodina
- Neoprioniodus
- Oistodus
- Ozarkodina
- Paltodus
- Panderodus
- Phragmodus
- Plectospathodus
- Prioniodina
- Pterospathodus
- Scolopodus
- Spathognathodus
- Tetraprioniodus
- Trichonodella
- Zygognathus