(Before caiman forms).
Named By: Charles W. Gilmore - 1946.
Synonyms: Hassiacosuchus kayi.
Classification: Chordata, Reptilia, Crocodilia, Alligatoridae, Alligatorinae.
Species: P. utahensis (type), P. kayi.
Size: Uncertain, but thought to be small.
Known locations: USA, Utah and Wyoming - Green River Formation.
Time period: Early Eocene.
Fossil representation: Holotype established from a skull and partial left hind leg. Additionally remains have since been attributed to the genus.
Procaimanoidea would have lived like a small
alligator feeding upon a
variety of animals from fish such as Diplomystus,
like freshwater shrimp. The main evidence for this comes from the two
different kinds of teeth in the jaws, sharper conical teeth in the
front, and more rounded teeth in the back. Procaimanoidea
have used these teeth to both seize slippery, soft bodied prey like
fish, while also cracking open the armoured exoskeletons of
invertebrates to get at the soft flesh within. However,
Procaimanoidea was not unique as other crocodiles
such as Bernissartia
from the early Cretaceous also had a similar variance in its teeth.
Another Eocene crocodile named Hassiacosuchus once had a second species named Hassiacosuchus kayi, but in 1967 this species was found to actually belong to the Procaimanoidea genus (study by Wassersug and Hecht). These attributed remains were used to establish the second species for Procaimanoidea, P. kayi.
- A new crocodilian, Hassiacosuchus kayi, from the Bridger Eocene beds of Wyoming. - Annals of Carnegie Museum 28:207-220. - C. C. Mook - 1941.
- A new crocodilian from the Eocene of Utah. - Journal of Paleontology 20(1):62-67. - C. W. Gilmore - 1946.
- The status of the crocodylid genera Procaimanoidea and Hassiacosuchus in the New World. - Herpetologica. 23 (1): 30–34. - R. J. Wassersug, M. K. Hecht - 1967.