Discoscaphites conradi adorned with Oysters

w/ Pseudoptera subtortusa (oysters)

found in Hoploscaphites nicolletii Zone, Trail City Member, in the Fox Hills Formation 

Upper Maastrichtian, Late Cretaceous, South Dakota, USA

The Fox Hills Formation Member, Zone and ammonite fauna

~ 66.5 MY

Protocardia-Oxytoma Assemblage Zone (also known as the transitional stage): Baculites larsoni, Discoscaphites conradi, D. gulosus, D. sp. cf. D. gulosus, D. rossae, Hoploscaphites nicolletii, H. spedeni, H. nebrascensis, Sphenodiscus beecheri, S. sp.