Bolg amondol: The “Hobbit Goblin” Giant Lizard That Raided Dinosaur Nests in Late Cretaceous Utah

A raccoon-sized but heavily armoured monstersaurian lizard, Bolg amondol, has been formally described from the Kaiparowits Formation of Grand Staircase-Escalante National Monument in southern Utah. Named after the ruthless goblin prince from J.R.R. Tolkien’s The Hobbit, this 76-million-year-old (Campanian) reptile reveals surprising diversity among large-bodied lizards living alongside dinosaurs.

The ᴀssociated skeleton—skull fragments, vertebrae, limbs, girdles, and distinctive osteoderms—was collected in 2005 but remained in museum drawers for two decades until detailed study in 2025. Published in iScience on 17 June 2025 by Hank Woolley, Joe Sertich and colleagues, the analysis places Bolg within the monstersaur lineage (helodermatids and kin) and highlights unique traits including armour fused to the jugal bone and a robust skull suited for a powerful bite.

Artistic reconstructions depict Bolg amondol raiding an oviraptorosaur nest, suggesting it may have specialised in raiding dinosaur eggs — a behaviour supported by its robust denтιтion and body armour that would have protected it from angry parents. At roughly one metre long, it was a formidable predator or scavenger in the lush, riverine ecosystems of western North America.

The discovery underscores how much remains hidden in museum collections and expands the known record of large lizards at the end of the Cretaceous. Housed at the Natural History Museum of Utah, Bolg amondol proves that even “small” monsters could thrive in the shadow of giants.