Cenomanian
Texas to Montana
Original presentation: Borissiakoceras orbiculatum
Original publication: Stephenson. 1955. [p. 64, pl. 6, figs 1-4].
Holotype: USNM 108832.
Type locality: near Mansfield, Texas (Kennedy and Cobban, 1990a).
Type horizon: “basal Eagle Ford Group” (Kennedy and Cobban, 1990a, p. 85).
Other specimens: USNM 420185-420194.
PaleoDB taxon number: 333410.
References: Kennedy and Cobban (1990a).