Who says scientists don't have a sense of humor? Paleontologists studying the fossilized remains of a giant, plant-eating lizard that roamed the country of Myanmar (Burma) up to 40 million years ago have given the creature the scientific name barbaturex morrisoni after classic rock icon Jim Morrison, lead singer of the Doors, who nicknamed himself "the Lizard King." More importantly, the date range ascribed to the fossilized bones indicates that the lizard lived at the same time as early mammals, a time period when the Earth was much warmer than it is today, when there was no ice at the poles and when there was more carbon dioxide in the atmosphere.

These facts, combined with the lizard's body size — about six feet long and 60 pounds — suggests that the comparatively smaller size of land lizards today is limited more by the cooler climate, and less by competition with other plant-eating mammals. "We think the warm climate during that period of time allowed the evolution of a large body size and the ability of plant-eating lizards to successfully compete in mammal faunas," said Jason Head, a paleontology professor at the University of Nebraska-Lincoln who lead the team studying the lizards. If Earth warms up at a steady pace again, the climate could prove favorable to the allow such giant lizards to evolve again, but Head said the climate is changing too rapidly now for that to be likely.

The fossil was first discovered in the 1970s, but was not studied closely until recently. When scientists reexamined it, they discovered that the teeth resembled plant-eating lizards of our time, including iguanas. The results are set to be published this week in the journal Proceedings of the Royal Society B, and will help scientists to better understand how drastically Earth's ecosystems and climate have changed over the millennia.