The 48-million-year-old skull of an ancient Jesus lizard relative found in Wyoming may shed light on the evolutionary history of lizards, iguanas and chameleons, a new study finds. Jesus lizards, named for their ability to scamper across water, typically live in the tropical environments of central Mexico and northern South America. But during the Eocene period, Wyoming was about 16 degrees Fahrenheit (9 degrees Celsius) warmer than now, making it an ideal environment for the lizards, the researchers said. [Read the full story on the fossil of the Jesus lizard relative]
A wild brown basilisk (Basiliscus vittatus), photographed in Guatemala. The animal is nicknamed Jesus lizard for its ability to run across water.
"They have very large feet, and they're able to move their legs very quickly," said the study's researcher Jack Conrad, an assistant professor anatomy at the NYIT College of Osteopathic Medicine. "They're able to use just the surface tension of water to flap their foot on the water and pull up before the water closes around the toes." (Image credit: Ana Balcarcel.)
Modern-day Jesus lizards are about 2 feet long (0.6 meters), but about two-thirds of that is tail, Conrad said. These long tails act as rudders and help the animals change direction. (Image credit: Ana Balcarcel.)
The 48-million-year-old skull of the Jesus lizard relative shows its teeth are remarkably similar to those of Jesus lizards today.
"Modern Jesus lizards eat everything from flowers to other lizards," Conrad told Live Science. He said he suspects the ancient lizard was also a generalist when it came to meals.
"Basically, if you were small enough for it to shove in its mouth, you're prey," Conrad said. (Image credit: Jack Conrad.)
A snapshot of the skull's underside. (Image credit: Jack Conrad.)
A CT scan of the lizard skull shows that the animal has a healed jaw fracture (see arrow). Such a fracture would have made it difficult for the lizard to hunt, since many lizards use their faces to attack prey, Conrad said.
"This is a pretty severely broken jaw based on what we can see in the CT scan," Conrad said. "It usually takes a pretty hearty animal to survive something like that." (Image credit: Jack Conrad.)
An artists' rendition of the ancient lizard's skull. The skull is almost complete: It's just missing the tip of its snout and a portion on the top of the head (seen in dark blue). (Image credit: Jack Conrad and Mick Ellison.)