A 120-million-year-old fossil is the oldest pregnant lizard ever discovered, according to scientists. Why is this interesting, you ask?
The fossil is especially interesting to scientists because it is a reptile that produced live young rather than laying eggs.
Only 20% of living lizards and snakes produce live young, and this shows it is an ancient, if unusual, trait.
“I didn’t think much of the fossil when I first saw it,” said Prof Susan Evans, joint lead author of the paper, from University College London.
But when her colleague, Yuan Wang, from the Chinese Academy of Sciences, examined the fossil he spotted the tiny remains of at least 15 almost fully developed embryos inside it.
“Sure enough, when I examined it under the microscope, I could see all these little babies,” Prof Evans recalled.The heads of at least 15 lizard embryos are visible inside the body of the fossil
The fossil is so well preserved that the minuscule teeth of the developing young are visible on very close inspection.