Newmarracarroceras

Newmarracarroceras is an ammonite from the early middle Jurassic with a ribbed subinvolute shell with a keel running along the venter, or outer rim. The umbilicus is moderately wide, exposing the inner whorls exposed in part.

Newmarracarroceras has a fairly wide geographic range and includes species previously described under Fontannesia. Related genera include Asthenoceras, Fontannesia, Guhsania, and Witchellia.