A remarkable fossil discovery in the Grand Staircase-Escalante National Monument in Utah has revealed a new species of armored lizard that coexisted with dinosaurs approximately 72 million years ago during the late Cretaceous period.

The newly identified species, named bolg amondol, belongs to the extinct group known as Monstertauria, ancient relatives of modern-day monitor lizards. This finding provides valuable insights into the diversity and evolution of reptiles during the age of dinosaurs.

Ancient Armored Lizard

“Monsteliuria groups have a history of evolution for nearly 100 million years, but their fossil records are still very limited.”

monstertaurians were a group of heavily armored lizards characterized by polygonal plates on their skulls and cone-shaped teeth. According to Paleontologist Hank Woolley from the Dinosaur Institute, the discovery of Bolg amondol is important because the fossil record for monstertauria is sparse, making this find crucial for understanding their evolutionary history.

Bolg amondol is estimated to have reached nearly one meter in length, comparable to the size of a modern Savannah Monitor lizard.The fossil remains, though incomplete, offer a glimpse into the size and structure of this ancient reptile.

Discovery in Ancient Tropical Forest

The fossil of bolg amondol was first discovered in 2005 in the Kaiparowits Formation, a region that was once a seasonal tropical forest in western North America during the geological period known as Laramidia. The fossil assemblage includes skull fragments, vertebrae, pelvic bones, leg bones, and osteoderms – the bony plates that formed the lizard’s armor.

Dr. Randy Irmis, Paleontologist from the University of Utah, emphasized the importance of museum collections in preserving and studying rare specimens like Bolg amondol. he noted that this discovery highlights how natural history collections can hold scientific treasures waiting to be rediscovered.

The discovery site also yielded evidence of at least three different types of large predatory lizards, indicating that the region was a diverse habitat for reptiles during the late Cretaceous. Though, Dr.Joe sertich from the Smithsonian Tropical Research Institute noted that the skeletal remains of these large lizards are rarely found,with most discoveries consisting of only a few bones or teeth.

Ecosystem Role

Large lizards like Bolg amondol likely played a significant role in the ancient ecosystems, potentially acting as mid-level predators that preyed on dinosaur eggs and other small animals on the forest floor. This suggests that the dinosaur era was more complex than previously thought, with a variety of medium-sized predators coexisting alongside dinosaurs.

The research team believes that the discovery of this new Monstertaurian species suggests that many more large lizard species from the Late Cretaceous period remain to be discovered. This underscores the vast amount of biodiversity that is still hidden within paleontological collections and unexplored fossil sites.

interestingly, the closest relatives of Bolg amondol have been found in Asia, specifically in the Gobi Desert. This suggests that despite their smaller size compared to dinosaurs, lizards were able to disperse across continents that were once connected, exhibiting similar patterns of distribution as dinosaurs and other terrestrial vertebrates during the Late Cretaceous.

The complete research findings have been published in the Royal Society Open Science journal, providing new insights into the evolution of large, non-dinosaurian reptiles in prehistoric times.