24-06-2025
‘Goblin prince': New monstersaur discovered in Utah reveals hidden secrets of Gila monster relatives
Artistic reconstruction of Bolg amondol, depicted raiding an oviraptorosaur dinosaur nest amidst the lush Kaiparowits Formation habitat. (Courtesy of Cullen Townsend/University of Utah)
When Hank Woolley, a paleontological researcher who specializes in lizard evolution, opened a jar of bones labeled 'lizard' at the Natural History Museum of Utah, he said his first thought was, 'Oh wow, there's a fragmentary skeleton here.'
'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,' said Woolley, from the Natural History Museum of Los Angeles County's Dinosaur Institute.
With Woolley's expertise, that jar of bones — even though it was collected back in 2005 — helped lead to a new discovery of a 'racoon-sized armored monstersaurian,' a giant relative of the Gila monster, according to an announcement issued last week by the University of Utah.
Its name, Bolg amondol, was inspired by a 'goblin prince' villain in J.R.R. Tolkien's 'Lord of the Rings' universe. Bolg now represents an 'evolutionary lineage that sprouted within a group of large-bodied lizards called monstersaurs that still roam the deserts from which Bolg was recovered,' according to the U.
Woolley knew that a new species of monstersaur called for an appropriate name from an 'iconic monster creator': Tolkien, the university said in its release.
'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,' Woolley said.
He also used Tolkien's fictional Elvish language Sindarin to craft the species' epithet. 'Amon' means 'mound,' and 'dol' means 'head,' a reference to mound-like osteoderms (or bony deposits that act as a form of armor) found on Bolg's and other monstersaurs' skulls.
''Mound-headed Bolg' would fit right in with the goblins — and it's revealing quite a bit about monstersaurs,' the U. said.
The research published June 17 in the journal Royal Society Open Science, led by the Dinosaur Institute in Los Angeles County and the Natural History Museum of Utah, 'reveals hidden treasures awaiting future paleontologists in the bowels of museum fossil collections,' the university said, along with 'the vast potential of paleontological heritage preserved in Grand Staircase-Escalante National Monument and other public lands.'
The field collection of the specimens were conducted under paleontological permits issued by the Bureau of Land Management, which also helped fund the study with a National Science Foundation award.
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Though the Bolg specimen was first unearthed more than a decade ago, in 2005, Woolley's expertise in lizard paleontology helped determine its significance. He was the lead author of the research.
'Bolg is a great example of the importance of natural history museum collections,' said co-author Randy Irmis, an associate professor at the U. and curator of paleontology at the Natural History Museum of Utah, in the news release. '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.'
Though museum collection spaces are 'sometimes stereotyped as dusty, forgotten places, the truth is quite the opposite,' the Natural History Museum of Utah said in a post about Bolg last week. The museum's paleontology collection is a 'glorified storage unit. Instead, it's a space where staff, students, volunteers, and visiting researchers can care for fossils and conduct new research.'
'It was this reevaluation of collection specimens,' the museum added, 'that led to Woolley's breakthrough research on Bolg amondol.'
Irmis said discovering a new species of lizard that's an ancestor of the modern-day Gila monster 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.'
'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,' Irmis said.
Researchers identified the new species from a collection of skull, limbs, vertebrae and bony armor called osteoderms. Most fossil lizards from the dinosaur age '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,' the U. said.
'That means more characteristics are available for us to assess and compare to similar-looking lizards,' Woolley said. '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.'
The clade (or ancestral grouping) of anguimorph lizards known as monstersauria are characterized by their large size and distinctive features, like 'sharp, spire-like teeth and pitted, polygonal armor attached to their skulls.'
Bolg, the U. said, 'would have been a bit of a monster to our eyes.'
'Three feet tip to tail, maybe even bigger than that, depending on the length of the tail and torso,' Woolley said. 'So, by modern lizard standards they're a very large animal, similar in size to a Savannah monitor lizard; something that you wouldn't want to mess around with.'
Monstersauria have a roughly 100-million-year history, but their fossil record is largely incomplete, meaning Bolg's discovery is a 'big deal' to help fully understand the prehistoric lizards and their world, the university said.
'Bolg's closest known relative hails from the other side of the planet in the Gobi Desert of Asia,' the U. said. 'Though dinosaurs have long been known to have traveled between the once-connected continents of the Late Cretaceous Period, Bolg reveals that smaller animals also made the trek, suggesting there were common patterns of biogeography across terrestrial vertebrates during this time.'
Bolg was discovered in the rocks of the Kaiparowits Formation of Grand Staircase-Escalante National Monument — a formation that has emerged as a paleontological hotspot over the past 25 years, according to the U.
Those rocks have produced 'one of the most astounding dinosaur-dominated records in North America,' the university said. 'Discoveries like this underscore the importance of preserving public lands in the Western U.S. for science and research.'
Co-author Joe Sertich, from the Smithsonian Tropical Research Institute and Colorado State University, said in the release that the 'exceptional record of big lizards' from Grand Staircase-Escalante 'may prove to be a normal part of dinosaur-dominated ecosystems from North America.'
He said those lizards appear to have filled 'key roles as smaller predators hunting down eggs and small animals in the forests of Laramidia,' which is an island continent that existed during the Late Cretaceous period.
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