A newly discovered, raccoon-sized armored monstersaurian from the Grand Staircase-Escalante National Monument in Southern Utah, United States, reveals a surprising diversity of large lizards at the pinnacle of the age of dinosaurs.

Named for the goblin prince from J.R.R. Tolkien’s “The Hobbit,” the new species Bolg amondol also illuminates the sometimes-murky path that life traveled between ancient continents.

“I opened this jar of bones labeled ‘lizard’ at the Natural History Museum of Utah, and was like, oh wow, there’s a fragmentary skeleton here,” said lead author Hank Woolley from the Natural History Museum of Los Angeles County’s Dinosaur Institute. “We know very little about large-bodied lizards from the Kaiparowits Formation in Grand Staircase-Escalante National Monument in Utah, so I knew this was significant right away.”

Published on June 17, 2025, in the journal Royal Society Open Science, the collaborative research led by the Dinosaur Institute and the Natural History Museum of Utah (NHMU) reveals hidden treasures awaiting future paleontologists in the bowels of museum fossil collections, and the vast potential of paleontological heritage preserved in Grand Staircase-Escalante National Monument and other public lands.

“Discovering a new species of lizard that is an ancestor of modern Gila monsters is pretty cool in and of itself, but what’s particularly exciting is what it tells us about the unique 76-million-year-old ecosystem it lived in,” said co-author Randy Irmis, associate professor of geology and geophysics at the University of Utah and curator of paleontology at NHMU. “The fact that Bolg co-existed with several other large lizard species indicates that this was a stable and productive ecosystem where these animals were taking advantage of a wide variety of prey and different micro-habitats.”

A Middle Earth-inspired moniker

Bolg represents an evolutionary lineage that sprouted within a group of large-bodied lizards called monstersaurs, which still roam the deserts from which Bolg was recovered. Woolley knew that a new species of monstersaur called for an appropriate name from an iconic monster creator, Tolkien.

“Bolg is a great sounding name. It’s a goblin prince from ‘The Hobbit,’ and I think of these lizards as goblin-like, especially looking at their skulls,” said Woolley. He used the fictional Tolkien Elvish language Sindarin to craft the species epithet. “Amon” means “mound,” and “dol” means “head,” a reference to the mound-like osteoderms found on Bolg’s and other monstersaur’s skulls. “Mound-headed Bolg” would fit right in with the goblins—and it’s revealing quite a bit about monstersaurs.

Hidden gems in collection drawers

The Bolg amondol discovery highlights the likelihood that more large-bodied lizards existed during the Late Cretaceous Period than previously thought. Bolg, along with other fossils from the Kaiparowits Formation, demonstrates that at least three types of predatory lizards lived in the Late Cretaceous sub-tropical floodplains of what is now Southern Utah. Additionally, this finding shows that unexplored diversity is waiting to be dug up both in the field and in paleontology collections.

“Bolg is a great example of the importance of natural history museum collections,” Irmis said. “Although we knew the specimen was significant when it was discovered back in 2005, it took a specialist in lizard evolution like Hank to truly recognize its scientific importance and take on the task of researching and scientifically describing this new species.”The researchers identified the new species from tiny pieces of skull, limbs, girdles, vertebrae and bony armor called osteoderms. Most fossil lizards from the age of dinosaurs are even scrappier—often just single, isolated bones or teeth—so despite their fragmentary nature, the parts of Bolg’s skeleton that survived contain a stunning amount of information.

“That means more characteristics are available for us to assess and compare to similar-looking lizards. Importantly, we can use those characteristics to understand this animal’s evolutionary relationships and test hypotheses about where it fits on the lizard tree of life,” Woolley said.

Gabriel "Gabe" Bowen assumes the position of chair in the Department of Geology & Geophysics beginning July 1, 2025

He replaces interim chair Kip Solomon.

Bowen grew up in rural Michigan and spent his childhood outdoors, which grew his love of nature and the earth. He received his bachelor’s in geology at the University of Michigan and went to UC Santa Cruz for a PhD in earth science. Bowen came to the U as a postdoc before joining Purdue University as a faculty member for seven years. He returned to the U through the Global Change and Sustainability Center and is now Professor of Geology & Geophysics and Co-Director of the Stable Isotope Facility for Environmental Research (SIRFER).

Recipient of a College of Science Excellence in Research Award, Bowen founded the Spatio-Temporal Isotope Analytics (SPATIAL) Lab, which uses stable isotope techniques to look at a lot of different areas of application of isotope geochemistry. “Isotope science has been kind of limited by our ability to make measurements,” says Bowen.

The SPATIAL Lab

The SPATIAL group has pushed forward uniting isotope geoscience with data science, which helps facilitate data sharing within and between fields of study. This data can then be leveraged to tackle bigger systems questions.

One focus of work within the SPATIAL group is reconstructing Earth’s climate through its geologic past and using that data to see changes in climate, ecosystems, and biogeochemical cycles, which can then be compared to modern day. The SPATIAL group is also studying how natural cycles operate today, such as the water cycle. Additionally, they also study spatial conductivity, or movement of things on the Earth’s surface, such as water, people, plants, and products.

One example is by using isotopes, Bowen looks at where plants are getting water from in the subsurface of the earth, which can show the stability of water supply within a community and help predict how water resources will change due to climate change.

“There’s an intimate coupling between the physical and biological processes that constitute a system,” Bowen says. “Isotopes are a common currency. The elements and isotopes that go through the water cycle or rock cycle are the same ones that go into an elephant or ponderosa pine. We can really bridge the gap and understand the connection across these spheres.”

Contextualizing current and future trends

“The Earth’s been through a lot,” Bowen says. “There’s a lot of context that shows how unusual what’s happening right now is. We’re pushing the climate system and carbon cycle much faster than it’s ever gone at any point in the geologic record.”

Bowen’s climate change research includes tracking the sources of water, such as where water originates before it makes its way to southern California. The isotopes of water in the Imperial Valley in California look more like isotopes in Colorado water than in water elsewhere in southern California. Most of the Imperial Valley water is irrigation water diverted from the Colorado River. The irrigation water becomes wastewater from irritation because of overwatering, and then it enters the groundwater. This has implications when agricultural runoff affects groundwater, as it could contain pesticides and other chemicals used in agricultural work.

The SPATIAL lab runs an annual summer course for graduate students, which provides training and experience in large-scale, data-intensive, geochemically oriented research. The course consists of a discussion and lecture in the morning, delivered by specialists in the field. Laboratory experiences introduce new techniques and hands-on learning.

“We live in a pretty amazing place for geology,” Gabriel Bowen says. He appreciates the geology of Utah from the air, as an amateur pilot. He flies a Cessna 182, mostly for geology sightseeing. He also participates in charity flying, taking people around Antelope Island for sightseeing of the Great Salt Lake. “I try to take my scientist and artist friends out to see things from a different perspective.”