Morrowites

Morrowites Temporal range: Turonian 94.3–89.3 Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓
Scientific classification
Kingdom:	Animalia
Phylum:	Mollusca
Class:	Cephalopoda
Subclass:	†Ammonoidea
Order:	†Ammonitida
Family:	†Acanthoceratidae
Subfamily:	†Mammitinae
Genus:	†Morrowites Cobban & Hook, 1983
Species
† M. depressus † M. dixeyi † M. subdepressus † M. wingi

Morrowites, named by Cobban and Hook, 1983, is 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 occasional 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.

Etymology[]

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

Distribution[]

Fossils of Morrowites have been found in Colombia (Loma Gorda Formation, Aipe, Huila),^[1] France, Germany, Mexico, Nigeria, and the United States (Arizona, New Mexico).^[2]

References[]

Bibliography[]

• Patarroyo, Pedro. 2011. Sucesión de Amonitas del Cretácico Superior (Cenomaniano-Coniaciano) de la parte más alta de la Formación Hondita y de la Formación Loma Gorda en la Quebrada Bambucá, Aipe - Huila (Colombia). Boletín de Geología, Universidad Nacional de Colombia 33. 69-92. Accessed 2017-03-30.

Further reading[]

• W. A. Cobban and S. C. Hook, 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