Pliosaurid tooth

This tooth was found in 1996 by Ben Van Ee on a Paleontology class trip south of Hawarden in NW Iowa. The fossil is from Cretaceous rock that is most likely Greenhorn formation. Since the Greenhorn was eroding it could possibly be the underlying Graneros. We originally thought it was a Mosasaur tooth since it corresponds fairly well (except for size) to the Mosasaur tooth Leidy 1873 found in the Niobrara formation (illustrated on plate 2 of Brian Witzke's article in Iowa Geological Survey Guidebook Series Number 4 of 1981). However, with the help of Dr. Gorden Bell we have identified it as a Pliosaurid tooth. These were large skulled (some up to 3 meters) and short necked marine "reptiles."  While they may have also fed on things like cephalopods some of these were really at the top of the food chain feeding even on other large marine reptiles like mosasaurs (sort of the killer whale of the Cretaceous oceans).    This tooth is one of the very few (third) reports of these creatures from Iowa.

  • One side of the tooth (Neg. 67,5a). 
  • Other side of the tooth (67, 6a). 
  • Shot of the inside and bottom of tooth (67,7a).

  • Page created for James Mahaffy, the paleontology prof., in 1996 by David Dykshoorn.