The myth of Parasaurolophus in Hell Creek

Skye McDavid, April 15, 2022

Parasaurolophus, with its long crest, is one of the most iconic dinosaurs, and in paleoart it is often depicted alongside an even more iconic dinosaur, Tyrannosaurus. This is wrong, but some instances of it may be based on an error in what is possibly the most important reference work on Dinosaurs. The second edition of The Dinosauria lists a possible occurrence of Parasaurolophus walkeri in the Hell Creek Formation. This is, quite simply, an error.

The material in question is AMNH FR 5893, a humerus and some unspecified fragments, collected in 1906 by Barnum Brown. It is listed in the American Museum of Natural History's catalog as belonging to Parasaurolophus walkeri. However, I find this identification questionable, as do several published sources. Lull and Wright 1942 simply list it as an indeterminate hadrosaur, while Carpenter et al 1995 and Pietro-Márquez et al 2012 both list is as cf Parasaurolophus sp.

Cast skull of Parasaurolophus walkeri (Academy of Natural Sciences of Drexel University)
Photo by Skye McDavid
Parasaurolophus walkeri holotype ROM 768 compared to AMNH FR 5893. Not to scale. Illustration by Skye McDavid, redrawn from Brett-Surman et al 2007.

The first wrinkle is that this specimen doesn't really look that much like Parasaurolophus. Although it's clearly a hadrosaur, the morphology of the humerus is somewhat different from that of Parasaurolophus. I think it's safest to consider it an indeterminate hadrosaur.

But there's an even bigger wrinkle. The "Hell Creek Parasaurolophus" isn't from the Hell Creek Formation. It was collected near Hell Creek, the creek that gives its name to the stratigraphic unit, but 30 meters below the base of the Hell Creek Formation itself, in the Pierre Shale. It appears that this occurrence of a hadrosaur considered by some to be similar to Parasaurolophus near Hell Creek, the creek, was misreported as an occurrence of Parasaurolophus itself in the Hell Creek Formation.

So if you want to illustrate Tyrannosaurus preying on a hadrosaur, it should be Edmontosaurus annectens.

Model of SUE the Tyrannosaurus eating a juvenile Edmontosaurus annectens.Field Museum/Liberty Science CenterPhoto by Skye McDavid


  • The Dinosauria (Second Edition) by David B. Weishampel, Peter Dodson, & Halszka Osmólska, 2004

  • American Museum of Natural History Paleobiology Database, FR 5893

  • Hadrosaurian Dinosaurs of North America by Richard Swann Lull & Nelda Emelyn Wright, 1942

  • Carpenter, K., Dilkes, D., Weishampel, D. B. (1995) The Dinosaurs of the Niobrara Chalk Formation (Upper Cretaceous, Kansas) Journal of Vertebrate Paleontology 15(2): 275-297

  • Pietro-Márquez, A., Chiappe L. M., Joshi S. H. (2012) The Lambeosaurine Dinosaur Magnapaulia laticaudus from the Late Cretaceous of Baja California, Northwestern Mexico. PLoS ONE (7)6: e38207

  • Brett-Surman, M. K., Wagner, J. R., & Carpenter, K. (2007). Discussion of character analysis of the appendicular anatomy in Campanian and Maastrichtian North American hadrosaurids—variation and ontogeny. Horns and beaks. Ceratopsian and ornithopod dinosaurs, 135-169.