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.

Conodonts

 * Acodus
 * A. inornatus
 * A. unicostatus


 * Ambalodus
 * A. triangularis


 * Amorphognatus
 * Belodella
 * B. flexa


 * Belodina
 * B. inclinata
 * B. ornata


 * Carniodus
 * Cordylodus
 * C. delicatus
 * C. flexuosus


 * Distacodus
 * D. mehli
 * D. posterocostatus
 * D. procerus


 * Distomodus
 * D. kentuckyensis


 * Drepanodus
 * D. homocurvatus
 * D. simplex


 * Eoligonodina
 * E. delicata


 * Hadrognathus
 * H. staurognathoides


 * Hindeodella
 * H. equidentata


 * Keislognathus
 * K. gracilis


 * Ligonodina
 * L. egregia
 * L. silurica


 * Neoprioniodus
 * N. bicurvatoides
 * N. planus


 * Oistodus
 * O. venustus


 * Ozarkodina
 * O. gaertneri
 * O. tenuis


 * Paltodus
 * P. multicostatus
 * P. trigonius


 * Panderodus
 * P. gracilis
 * P. miseri
 * P. simplex
 * P. sulcatus
 * P. unicostatus


 * Phragmodus
 * P. undatus


 * Plectospathodus
 * P. extensus


 * Prioniodina
 * P. irregularis


 * Pterospathodus
 * Scolopodus
 * S. insculptus


 * Spathognathodus
 * S. manganiferus
 * S. procerus
 * S. sweeti
 * S. wolfordi


 * Tetraprioniodus
 * T. superbus


 * Trichonodella
 * T. brassfieldensis
 * T. carinata
 * T. diminuta
 * T. exacta
 * T. variflexa


 * Zygognathus
 * Z. mira