June 14, 2013 – The biggest known lizard to ever walk the Earth has been named after Jim Morrison, the lead singer of The Doors, a popular band from the late 1960s and early 1970s.
How did a lizard get named after a legendary musician, you might ask?
In 1969 Morrison wrote and recorded a performance piece consisting of poems, musical sections, and spoken verses named "Celebration of the Lizard King."
"I was listening to The Doors quite a bit during the research," said the study's lead author Jason Head of the University of Nebraska-Lincoln. "Some of their musical imagery includes reptiles and ancient places, and Jim Morrison was of course The Lizard King, so it all kind of came together," Head explained.
The vegetarian Barbaturex morrisoni, or Lizard King, roamed the lands of South East Asia 36 to 40 million years ago. It was six feet long and likely weighed 60 pounds (27.2 kilograms).
The Lizard King most likely became as big as it was because of high temperatures at the time. Head believes that the warm climate allowed animals to grow larger bodies, which gave vegetarian lizards an equal playing field to complete with other plant-eating mammals for food on.
"You can't fully understand the evolution of ecosystems in the modern world without looking at the ones that [came before] them," said Head.
The Earth's most recent large reptiles –the Komodo Dragon, and the Cretaceous Chinese Chianghsia nankangensis and the Pleistocene Australian Varanus priscus– are all meat-eaters. They did not have to compete with the animals they lived with because they could easily just eat them. "What is interesting about the Lizard King is that it was a large vegetarian co-existing and and competing with other [vegetarian] mammals," explained Head.
Even though Barbaturex morrisoni dwarfs today's lizards it wasn't completely safe from predators during its time. "The large size of the Lizard King certainly protected it from many predators. But there is no doubt that it was hunted by mammalian carnivores of the day."
The Lizard King teaches us that climate had a much more important role in the evolution of vegetarian reptiles than we thought, according to Head. If the Earth's current climate turned just hot enough giant lizards could certainly evolve again, but because we are warming the Earth's atmosphere so fast reptiles aren't able to adapt fast enough and will likely stay the same size.