Watinoceras
Watinoceras is a genus of acanthoceratid ammonite that lived during the early Turonian stage of the Late Cretaceous.
Early whorls are compressed, finely ribbed with inner and outer ventrolateral and siphonal tubercles as in Neocardioceras, but siphonal row is soon lost. Later the venter may be concave between rows of ventrolateral clavi or rounded with ribs passing over in chevrons. Ornament usually becomes coarser with age. Derivation is from Neocardioceras. Watinoceras and Mammites gave rise to the other genera in the subfamily. Older classifications included Watinoceras in the subfamily Mammitinae instead.
Species include Watinoceras coloradoense, W. reesidei, and W. thompsonense.
The first occurrence of the species Watinoceras devonense marks the beginning of the Turonian.
