''Parapuzosia bradyi'' is a gigantic
species
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...
of
ammonite, reaching diameters of more than by . It is the largest species of ammonite in
North America. It had a moderately involute shell with flat sides. The inner whorls are slightly oval-shaped with prominent ribbing. They are only known from the upper layers of the
Eagle Sandstone and
Cody Shale formations (both
Late Cretaceous
The Late Cretaceous (100.5–66 Ma) is the younger of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''creta'', ...
).
References
Cretaceous ammonites
Desmoceratidae
{{Ammonitina-stub