The ancient creature boasted “goblin-like” teeth and a customizable tail.

An extinct creature uncovered in North America offers fresh insights into the region’s life around 75 million years ago.

The creature has been described as “looking like a goblin jumping out of a rock,” according to Hank Woolley of the Los Angeles County Natural History Museum. This species, known as Monstaurus, is part of a group of reptiles that thrived during the late Cretaceous period. Woolley notes it could have been “around 3 to 4 feet from tail to tip.” “Best to stay away,” he warns.

Woolley named the species Borguamondor. The first part of the name derives from a Lord of the Rings character, while the second part is inspired by an invented Elvish word, referring to its bone armor — a trait shared with its relatives, modern Gira Monsters (Healoderma Sumpectum).

Remarkably preserved fossils were found in Utah two decades ago by Joseph Sertich. Initially, the Smithsonian Tropical Research Institute believed it was a prehistoric lizard. Sertich recalls, “I found a collection of scattered bones in a low, flat sandy area,” including the skull, vertebrae, jawbone, and parts of a hip bone.

Sertich encouraged Woolley to investigate the fossils at the museum in 2022. B. Amondor represents an extinct species of lizard known as the Monstaurus. They found evidence that some could shed their tails when injured, making it the oldest known example of this defensive strategy that modern lizards employ.

According to researchers, B. Amondor dined on small mammals, frogs, snakes, insects, and “things not primarily plants,” even considering dinosaur eggs as part of its “round-length” diet. Its habitat was likely a wetland ecosystem, quite hot and humid, resembling the modern-day U.S. Gulf Coast rather than the arid landscape we see today.

Randall Nydam from Midwest University in Illinois, though not involved in this research, emphasizes the cautionary aspect of the story, reflecting on the vulnerabilities of such formidable “monsters,” both ancient and modern. “We must also acknowledge that they are long gone,” he states, “vanished due to changing circumstances.”

Continuing the dialogue about B. Amondor, Sertich believes people should broaden their understanding of these creatures. “Imagining North America’s primal tropical forests should portray nightmare lizard-hunting dinosaurs navigating the underbrush and scaling trees,” he suggests.