Newmarracarroceras is an ammonite from the early middle Jurassic[1] 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.

This Ammonitina-related article is a stub.