Discoscaphites cf. D. gulosus with multiple gastropods

Hoploscaphites nicolletii Zone,

Trail City Member, Fox Hills Formation

Upper Maastrichtian, Late Cretaceous

South Dakota, USA

Fox Hills Formation Member, Zone and ammonite fauna

~ 66.5 MY

Trail City Member

upper Hoploscaphites nicolletii Range Zone

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.

Upper nicolletii Assemblage Zone: Discoscaphites conradi, D. sp. cf. D. gulosus, Hoploscaphites nicolletii, Hoploscaphites spedeni, Sphenodiscus sp. (in pre 1996 publications called S. lenticularis), Trachybaculites columna