A newly found, raccoon-sized armored monstersaurian from the Grand Staircase-Escalante Nationwide Monument in Southern Utah, United States, reveals a shocking range of huge lizards on the pinnacle of the age of dinosaurs. Named for the goblin prince from J.R.R. Tolkien’s “The Hobbit,” the brand new species Bolg amondol additionally illuminates the sometimes-murky path that life traveled between historic continents.
“I opened this jar of bones labeled ‘lizard’ on the Pure Historical past Museum of Utah, and was like, oh wow, there is a fragmentary skeleton right here,” mentioned lead writer Hank Woolley from the Pure Historical past Museum of Los Angeles County’s Dinosaur Institute. “We all know little or no about large-bodied lizards from the Kaiparowits Formation in Grand Staircase-Escalante Nationwide Monument in Utah, so I knew this was important immediately.”
Revealed on June 17, 2025 within the journal Royal Society Open Science, the collaborative analysis led by the Dinosaur Institute and the Pure Historical past Museum of Utah (NHMU) reveals hidden treasures awaiting future paleontologists within the bowels of museum fossil collections, and the huge potential of paleontological heritage preserved in Grand Staircase-Escalante Nationwide Monument and different public lands.
“Discovering a brand new species of lizard that’s an ancestor of contemporary Gila monsters is fairly cool in and of itself, however what’s notably thrilling is what it tells us in regards to the distinctive 76-million-year-old ecosystem it lived in,” mentioned co-author Randy Irmis, affiliate professor on the College of Utah and curator of paleontology at NHMU. “The truth that Bolgco-existed with a number of different massive lizard species signifies that this was a secure and productive ecosystem the place these animals had been making the most of all kinds of prey and totally different micro-habitats.”
A Center Earth-inspired moniker
Bolg represents an evolutionary lineage that sprouted inside a bunch of large-bodied lizards known as monstersaurs, that also roam the deserts from which Bolg was recovered. Woolley knew {that a} new species of monstersaur known as for an acceptable identify from an iconic monster creator, Tolkien.
“Bolg is a superb sounding identify. It is a goblin prince from ‘The Hobbit,’ and I consider these lizards as goblin-like, particularly their skulls,” mentioned 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 discovered on Bolg’s and different monstersaur’s skulls. “Mound-headed Bolg” would match proper in with the goblins — and it is revealing fairly a bit about monstersaurs.
Hidden gems in assortment drawers
The Bolg amondol discovery highlights the chance that extra large-bodied lizards existed through the Late Cretaceous Interval than beforehand thought. Bolg, together with different fossils from the Kaiparowits Formation, exhibit at the very least three varieties of predatory lizards lived within the Late Cretaceous sub-tropical floodplains of what’s now Southern Utah. Moreover, this discover reveals that unexplored range is ready to be dug up each within the area and in paleontology collections.
“Bolg is a superb instance of the significance of pure historical past museum collections,” Irmis mentioned. “Though we knew the specimen was important when it was found again in 2005, it took a specialist in lizard evolution like Hank to really acknowledge its scientific significance and tackle the duty of researching and scientifically describing this new species.”
The researchers recognized the brand new species from tiny items of cranium, limbs, girdles, vertebrae and bony armor known as osteoderms. Most fossil lizards from the age of dinosaurs are even scrappier — usually simply single, remoted bones or enamel — so regardless of their fragmentary nature, the components of Bolg‘s skeleton that survived comprise a surprising quantity of knowledge.
“Which means extra traits can be found for us to evaluate and examine to similar-looking lizards. Importantly, we are able to use these traits to grasp this animal’s evolutionary relationships and check hypotheses about the place it matches on the lizard tree of life,” Woolley mentioned.
Stairway to monstersaurs
The monstersauria are characterised by their massive dimension and distinctive options, corresponding to sharp, spire-like enamel and pitted, polygonal armor hooked up to their skulls. They’ve a roughly 100-million-year historical past, however their fossil report is essentially incomplete, making the discoverya massive deal for understanding these charismatic lizards. Bolg would have been a little bit of a monster to our eyes.
“Three ft tip to tail, perhaps even greater than that, relying on the size of the tail and torso,” mentioned Woolley. “So, by trendy lizard requirements they seem to be a very massive animal, comparable in dimension to a Savannah monitor lizard; one thing that you just would not wish to fiddle with.”
Bolg’s closest recognized relative hails from the opposite aspect of the planet within the Gobi Desert of Asia. Although dinosaurs have lengthy been recognized to have traveled between the once-connected continents of the Late Cretaceous Interval, Bolg reveals that smaller animals additionally made the trek, suggesting there have been frequent patterns of biogeography throughout terrestrial vertebrates throughout this time.
The rocks the place Bolg was found — the Kaiparowits Formation of Grand Staircase-Escalante Nationwide Monument — have emerged as a paleontological hotspot over the previous 25 years, producing one of the astounding dinosaur-dominated data in North America. Discoveries like this underscore the significance of preserving public lands within the Western U.S. for science and analysis.
“The distinctive report of huge lizards from Grand Staircase-Escalante Nationwide Monument might show to be a traditional a part of dinosaur-dominated ecosystems from North America, filling key roles as smaller predators looking down eggs and small animals within the forests of Laramidia,” mentioned co-author Joe Sertich from the Smithsonian Tropical Analysis Institute and Colorado State College.
This story is edited from the unique by Tyler Hayden, science communication specialist, Pure Historical past Museum of Los Angeles County.
Different authors embody Keegan Melstrom, College of Central Oklahoma and Nathan Smith, Pure Historical past Museum of Los Angeles County, Dinosaur Institute. Area assortment of the specimens described on this examine was carried out beneath paleontological permits issued by the Bureau of Land Administration (BLM). This examine was funded by the BLM, Nationwide Science Basis award 2205564, the Pure Historical past Museum of Los Angeles Dinosaur Institute and the College of Utah.
