undet. Mollusca
From the collection of Yale Peabody Museum. Free to download, adapt and use — no permission needed.
Geological context: Late Cretaceous, Fox Hills Fm, Trail City Mbr. Collection locality: various layers in road cut on E side of spur and on W side of old US 12 about .75 mi S of intersection with Wakpala road, N side of hill with Ridgeview 1954 bench mark, and 4.5 mi S of Mahto, Corson County, South Dakota, USA. Collected by Karl M. Waage, George Colton, 1949. IP number 561377; lot count 1; taphonomy=concretion; accn=IPA.07048; associatedwith=on same slab: IP.561377,IP.561952,IP.561953,IP.561970,IP.561971,IP.561959,IP.561963,IP.561965,IP.561966,IP.561974,IP.561976,IP.561977,IP.561979,IP.561980,IP.561981,IP.561951,IP.561978,IP.561950,IP.561954,IP.561955,IP.561956,IP.561957,IP.561958,IP.561967,IP.561968,IP.561969,IP.561972,IP.561960,IP.561961,IP.561962,IP.561964,IP.561973,IP.561975.
Yale Peabody Museum’s own description