Maastrichtian.
South Dakota.
Original presentation: Discoscaphites rossi
Original publication: Landman, N. H. and K. M. Waage. 1993. Scaphitid ammonites of the Upper Cretaceous (Maastrichtian) Fox Hills Formation in South Dakota and Wyoming. Bulletin of the American Museum of Natural History, Number 215, 257 pp. [p. 231-240; figs. 181-189].
Holotype: YPM 23052.
Type locality: Dewey County, South Dakota.
Type horizon: Fox Hills Formation (Timber Lake Member).
Other specimens: AMNH 44340, AMNH 44335, AMNH 44336, AMNH 44344, AMNH 44679, AMNH 44680, YPM 27084, YPM 23085, YPM 23095, YPM 23108, YPM 23096, YPM 23090, YPM 23094, YPM 23097, YPM 27081, YPM 23100, YPM 23083, YPM 23105, YPM 23093, YPM 23103.
PaleoDB taxon number: 145275.
Reference: Landman and Waage (1993).
Origin of name: “named in honor of Mrs. Helen Ross” (Landman and Waage, 1993, p. 232).