Eucaylptocrinus crassus Hall 1863.
Beautifully preserved Crinoid calyx. This species is noteworthy for having 20 arms. This specimen shows 13 of them. Lovely preservation. Nice detail under magnification of the plates etc.
Silurian, Waldron Shale Formation.
Sellersberg, Shelby County, Indiana, USA.
Calyx : 5 cm long.
