A giant, plant-eating lizard successfully competed with mammals about 40 million to 36 million years ago.

Researchers led by Jason Head at the University of Nebraska-Lincoln identified the lizard in a diverse assemblage of fossils collected in Myanmar. The teeth and jaws of the creature revealed that it was a plant-eater, and at an estimated 27 kilograms, it was one of the largest animals in the area. The researchers dubbed the species — which was almost twice the length of any living herbivorous lizard — Barbaturex morrisoni after the singer Jim Morrison, who famously proclaimed himself the lizard king.

Reptiles need external heat to keep their bodies warm, so the hotter temperatures of past climates could have allowed the large lizards to survive, the authors say.

Proc. R. Soc. B 280, 20130665 (2013)