Protocardia sp.
From the collection of Yale Peabody Museum. Free to download, adapt and use — no permission needed.
Geological context: Late Cretaceous, Fox Hills Fm, Timber Lake Mbr. Collection locality: float, grass-covered bluffs on E and SE side of SD Rt. 65, and on E and W sides of draw, 1 mi N of Moreau River, Ziebach County, South Dakota, USA. Collected by Karl M. Waage, George Colton, 1951. IP number 590092; lot count 1; taphonomy=concretion; accn=IPA.07048; associatedwith=IP.591209,IP.591210,IP.591212,IP.591208,IP.591211,IP.591213,IP.591215,IP.591299,IP.591300,IP.591301,IP.591302,IP.591303,IP.591304,IP.591305,IP.591306,IP.591307,IP.591308,IP.591309,IP.591310,IP.591311,IP.591312,IP.591313,IP.591314,IP.591315,IP.591316,IP.591317,IP.591318,IP.591319,IP.591320,IP.591321,IP.591322,IP.591323,IP.591324,IP.591325,IP.591326,IP.591327,IP.591328,IP.591329,IP.591330,IP.591331,IP.591332,IP.591333,IP.591334,IP.591214,IP.591216.
Yale Peabody Museum’s own description