undet. Bivalvia
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 561340; lot count 1; taphonomy=concretion; accn=IPA.07048; associatedwith=IP.561565,IP.561566,IP.561567,IP.561568,IP.561569,IP.561570,IP.561571,IP.561572,IP.561573,IP.561574,IP.561557,IP.561575,IP.561558,IP.561559,IP.561560,IP.561561,IP.561562,IP.561563,IP.561564,IP.561576,IP.561577,IP.561578,IP.561579,IP.561580,IP.561581.
Yale Peabody Museum’s own description