'Overlooked' Dinosaur Kept in US Museum Is Way More Amazing Than We Thought

An "overlooked" dinosaur generally considered to be "pretty boring" is far more interesting than previously thought.

In a study published in the journal Scientific Reports, a team of researchers found that the dinosaur likely had a super sense of smell and outstanding balance. The research involved examinations of a specimen known as Willo, which is on display at the North Carolina Museum of Natural Sciences in Raleigh.

Willo represents a species known as Thescelosaurus neglectus, whose scientific name roughly translates to "wonderful, overlooked lizard."

T. neglectus was a relatively small, herbivorous dinosaur, measuring around 12 feet in length, that was quite heavy, weighing in at roughly 750 pounds. It lived in what is now North America in the period just before the mass extinction event around 66 million years ago, which led to the extinction of all non-avian dinosaurs.

The name Thescelosaurus neglectus is a nod to the fact that the dinosaur was not recognized as a unique species until decades after the first fossils were collected in the late 19th century. While numerous T. neglectus bones have been recovered to date, the species is often overlooked in books and museums in favor of its iconic contemporaries, such as Tyrannosaurus rex and Triceratops.

"The North Carolina Museum of Natural Sciences has one of the best preserved skeletons of Thescelosaurus. We wanted to learn more about its behavior and ecology using its excellently preserved skull," Lindsay Zanno, head of paleontology at the museum and a co-author of the study, told Newsweek.

In the latest study, researchers conducted CT scans of the dinosaur's skull and used them to reconstruct the soft tissues—such as the brain and inner ear—that have been lost in the process of fossilization.

The scientists then compared their results to other dinosaurs and their living relatives, which allowed the researchers to determine the relative size of Willo's brain, as well as what her senses of smell, hearing and balance may have been like.

The work revealed that while the dinosaur may not have been particularly "brainy," it appears to have had a unique combination of traits.

"We found that Thescelosaurus had poor hearing, a great sense of smell and balance and comparatively simple cognitive ability, compared to many of its highly social, flamboyant cousins," Zanno told Newsweek.

"The irony is that paleontologists generally think of these animals as pretty boring. When we first looked at our results we thought, yeah, this animal is plain as toast. But then we took a big step back and realized there was something unique about the combination of Willo's sensory strengths and weaknesses," Zanno said in a press release.

The researchers found that the olfactory bulbs—the regions of the brain that process smell—were very well developed in Thescelosaurus neglectus. This suggests that it had an excellent sense of smell.

"[The olfactory bulbs] were relatively larger than those of any other dinosaur we know of so far, and similar to those of living alligators, which can smell a drop of blood from miles away," David Button, another study author who is currently a research associate at the University of Bristol in the United Kingdom, said in the press release.

"Thescelosaurus may have used its similarly powerful sense of smell to instead find buried plant foods like roots and tubers. It also had an unusually well-developed sense of balance, helping it to pinpoint its body position in 3D space, another trait often found in burrowing animals."

Despite its excellent sense of smell, the researchers found that the dinosaur's range of hearing was limited. The dinosaur could only hear about 15 percent of the frequencies humans can detect and between 4-7 percent of what dogs and cats can hear. T. neglectus was particularly bad at hearing high-pitched sounds.

"We found that Thescelosaurus heard low frequency sounds best, and that the range of frequencies it could hear overlaps with T. rex," Zanno said. "This doesn't tell us they were adapted to hearing T. rex vocalize, but it certainly didn't hurt them to know when a major predator was tooling about in the area. More interesting to us was the fact that these particular deficiencies are often associated with animals that spend time underground."

T. neglectus' poor cognitive and hearing abilities, coupled with powerful arms and legs and overdeveloped senses of smell and balance, are all features characteristic of modern animals that spend time underground and/or engage in digging behaviors.

"While we can't say definitively that these animals lived part of their lives underground, we know that their ancestors did," Button said. "This fact, together with their unique combination of sensory abilities, strongly suggests T. neglectus engaged in similar behaviors."

"We still don't know the sensory abilities of most dinosaurs," Zanno said. "That makes it difficult to link these traits to specific lifestyles with confidence, but it also means there are plenty of cool discoveries to come."

"The idea that there might have been dinosaurs living under the feet of T. rex and Triceratops is fascinating. No matter what, we now know for certain that T. neglectus isn't boring."

Update 11/10/23, 3:33 p.m. ET: This story was updated with additional comments from Lindsay Zanno of the North Carolina Museum of Natural Sciences.