Cenomanian to Turonian
Texas to Minnesota
Original presentation: Sphenodiscus dumbli Cragin, 1893
Original publication: Cragin. 1893. [p. 243, pl. 44, fig. 6].
Other occurrences: Nigeria, “Sciponoceras gracile zone correlative in Sarthe and Loire-Atlantique, France” (Kennedy and Cobban, 1990a, p. 91)
PaleoDB taxon number: 144336.
Synonyms: Sphenodiscus dumbli Cragin, 1893 (source: Kennedy and Cobban, 1990a).