Maastrichtian.
South Dakota to North Dakota.
3D model of species created by Shellie Luallin:
Original presentation: Jeletzkytes spedeni
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. 129-161, figs. 92-119].
Holotype: YPM 27160.
Type locality: Corson County, South Dakota.
Type horizon: Fox Hills Formation (Trail City Member).
Other specimens: YPM 23710, YPM 23124, YPM 24817, YPM 27156, YPM 23122, YPM 23206, YPM 23211, YPM 23775, YPM 23778, YPM 23205, YPM 23704, YPM 23199, YPM 23718, YPM 23204, YPM 23699, YPM 23200, YPM 23706, YPM 23714, YPM 31803, YPM 27156, YPM 27153, YPM 27151, YPM 27152, YPM 23710, YPM 27091, YPM 23062, YPM 23061, YPM 32593, YPM 32602, USNM 468854, USNM 468855, USNM 468856, USNM 468857, USNM 468858; also see Landman and Waage (1993).
PaleoDB taxon number: 145264.
Synonyms: Jeletzkytes spedeni (Landman and Waage, 1993).
Reference: Landman and Waage (1993).
Origin of name: “named for Ian G. Speden” (Landman and Waage, 1993, p. 129).