Drepanochilus sp.
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: Drepanochilus conc., W side of creek, toe of NE-trending spur, .6-.8 mi E of SD Rt. 63, SE of O'Leary ranch house, and about 1 mi N of Moreau River, and 4.5 mi NNE of Green Grass, Dewey County, South Dakota, USA. Collected by Ian G. Speden, 1962. IP number 856280; lot count 1; taphonomy=concretion; accn=IPA.07048; associatedwith=on same slab: IP.856280,original label stored with this specimen: IP.856420,IP.856289,IP.856290,IP.856291,IP.856292,IP.856281,IP.856282,IP.856283,IP.856284,IP.856285,IP.856286,IP.856287,IP.856288,IP.856293,IP.856294,IP.856295,IP.856296.
Yale Peabody Museum’s own description