undet. Bivalvia

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 590104; lot count 1; taphonomy=concretion; accn=IPA.07048; associatedwith=IP.590887,IP.590888,IP.590889,IP.590890,IP.590891,IP.590892,IP.590893,IP.590894,IP.590895,IP.590896,IP.590897,IP.590898,IP.590899,IP.590900,IP.590901,IP.590902,IP.590903,IP.590904,IP.590905,IP.590906,IP.590907,IP.590908,IP.590909,IP.590910,IP.590911,IP.590912,IP.590913,IP.590914,IP.590915,IP.590916,IP.590917,IP.590918,IP.590919,IP.590920,IP.590921,IP.590922,IP.590923,IP.590924,IP.590925,IP.590926,IP.590927,IP.590928,IP.590929,IP.590930,IP.590931,IP.590932,IP.590933,IP.590934,IP.590935,IP.590936,IP.590937,IP.590938,IP.590939,IP.591252.