undet. Bivalvia
From the collection of Yale Peabody Museum. Free to download, adapt and use — no permission needed.
Geological context: Late Cretaceous, Marias River Sh, Kevin Mbr. Collection locality: lower of 2 limestone concretion layers in lower part of Kevin, N bank of Marias River, along US Rt 15, & about 6.5 mi SSW of Shelby, Toole County, Montana, USA. Collected by Neil H. Landman, Susan M. Kidwell, 1978. IP number 390754; lot count 1; accn=IPA.07111; associatedwith=IP.852194,IP.852195,IP.852196,IP.852197,IP.852198,IP.852199,IP.852200,IP.852201,IP.852202,IP.852203,IP.852204,IP.852205,IP.852206,IP.852207,IP.852208,IP.852209,IP.852210,IP.852291,IP.852292,IP.852294,IP.852296,IP.852298,IP.852299,IP.852300,IP.852301,IP.852293,IP.852295,IP.852297.
Yale Peabody Museum’s own description