Morrowites

Morrowites Temporal range: mid Cretaceous (L Turonian)
Scientific classification
Kingdom:	Animalia
Phylum:	Mollusca
Class:	Cephalopoda
Subclass:	Ammonoidea
Order:	Ammonitida
Suborder:	Ammonitina
Superfamily:	Acanthocerataceae
Family:	Acanthoceratidae
Subfamily:	Mammitinae
Genus:	Morrowites Cobban and Hook, 1983

Morrowites, named by Cobban and Hook, 1983, is described in Memoir 41 NMBM&MR as a moderate to large-sized ammonite with quadrangular to depressed whorls, broadly rounded to depressed venter, low ribs, umbilical and inner and outer ventrolateral tubercles and smooth early whorls except for occsional ribs along weak constrictions. The suture is moderately simple and has an unusually broad bifid first lateral lobe. It is so far restricted to the Lower Turonian stage, in the mid Cretaceous.

Morrowites closely resembles Mammites, however Morrowites has a broad first lateral lobe, Mammites has a narrow one. The very early whorls of Morrowites are smooth except for distantly placed ribs and constrictions, those of Mammites have normal ribs and tubercles.

Morrowites is named in honor of A. L. Morrow who made a pioneering study of Cenomanian and Turonian ammonites of Kansas.

References

• W. A. Cobban and Hook, S. C. 1983 Mid-Cretaceous (Turonian) ammonite fauna from Fence Lake area of west-central New Mexico. Memoir 41, New Mexico Bureau of Mines&Mineral Resources, Socorro NM.