The dinosaur Uteodon, formerly known as Camptosaurus.
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Photo by Daderot, image from Wikiepdia.
The dinosaur Uteodon, formerly known as Camptosaurus.

U is for Uteodon

Last week I wrote about the enormous Jurassic carnivore Torvosaurus. The theropod was undoubtedly a sharp-toothed nightmare, but what did the rapacious giant eat? The even-larger sauropod dinosaurs that plodded around during the same time are obvious candidates – big predators would seem well-suited to chasing even larger prey. Yet, as paleontologists such as Dave Hone and Oliver Rauhut have argued, large meat-eating dinosaurs probably relied on relatively small fare. An 80-foot-long adult Apatosaurus was probably too much for even the largest Torvosaurus to handle, and so the Jurassic megalosaur most likely targeted juvenile sauropods and other comparatively little herbivores. Among the possible menu items – a mid-sized, bipedal, beaked ornithopod called Uteodon aphanoecetes.

After studying the dinosaur’s nearly complete postcranial skeleton, paleontologist Andrew McDonald named Uteodon in 2011. But the dinosaur’s backstory goes deeper than that.

The bones of Uteodon were found nearly a century ago in the roughly 150 million year old rock of what is now known as Dinosaur National Monument, Utah. The animal’s remains closely resembled that of a classic Jurassic dinosaur called Camptosaurus – named by paleontologist Othniel Charles Marsh in 1885 – and so it’s not surprising that dinosaur expert Charles Gilmore assigned the skeleton to the species Camptosaurusmedius.” (Later, the skeleton was bumped to the species Camptosaurus dispar).

Slowly, paleontologists began to realize that the Dinosaur National Monument Camptosaurus was not quite what it seemed. In 2008, Kenneth Carpenter and Yvonne Wilson determined that the skeleton differed enough from other Camptosaurus to justify establishing a new species – Camptosaurus aphanoecetes. Andrew McDonald went a step further in his 2011 reanalysis of Camptosaurus. While superficially similar, the DNM skeleton differed in various details of the braincase, shoulder, hip, and other parts of the skeleton. Rather than being just another Camptosaurus, McDonald made the case that the dinosaur was distinct enough to justify a new genus. Keeping the new species name coined by Carpenter and Wilson, McDonland rechristened the dinosaur Uteodon aphanoecetes.

Like many other Morrison Formation dinosaurs, there’s still much we don’t know about the biology of Uteodon. The dinosaur appears to have been a relatively plain herbivore, and may have relied on speed to run away from Allosaurus and other carnivores of the era (as in the Planet Dinosaur clip above). Hopefully, as they continue to draw tales from bone, paleontologists will someday be able to visualize the role Uteodon and other dinosaurs played in Jurassic ecosystems in greater detail.

Previous entries in the Dinosaur Alphabet series:

T is for Torvosaurus

S is for Segisaurus

R is for Rapetosaurus

Q is for Qiaowanlong

P is for Pelecanimimus

O is for Ojoceratops

N is for Nqwebasaurus

M is for Montanoceratops

L is for Leaellynasaura

K is for Kileskus

J is for Juravenator


Hone, D., Rauhut, O. 2009. Feeding behaviour and bone utilization by theropod dinosaurs. Lethaia. 43, 2: 232-244

McDonald, A., 2011. The taxonomy of species assigned to Camptosaurus (Dinosauria: Ornithopoda). Zootaxa. 2783: 52-68

Top image: Photo by Daderot, image from Wikipedia.