Lizards preserved in mid-Cretaceous amber from Myanmar.
Credit: Daza et al. Sci. Adv. 2016; 2 : e1501080
These tiny ancient lizards found well-preserved in amber provide a glance at what life would have been like nearly 100 million years ago, researchers from the American Museum of Natural History and Sam Houston State University explained in a newly-published study.
Writing in the latest edition of the journal Science Advances, lead author and SHSU professor Juan Diego Daza and his colleagues revealed that they discovered 12 of the pint-sized reptiles entombed in amber within a private collection of stones donated to the American Museum of Natural History by their previous owner.
Juan D. Daza, the study’s lead author and a biology professor at Sam Houston State University in Texas, told Live Science in an email that the lizards’ body lengths — minus their tails — ranged from 0.4 inches (11 millimeters) to about 1.6 inches (40 mm). One partial specimen might have been at least 2.4 inches (60 mm) long.
Stanley told Live Science that he was amazed by how closely certain individual lizards resembled their modern kin. “If you showed me the CT scans we made, I’d say that was a species of modern gecko,” he said. “Except when you start looking closer, you found a couple of characters that no gecko has today.”
One of the preserved lizards in particular was “very interesting,” Daza said. The tiniest of the specimens, presumably newly hatched, was described in the paper as a “stem chameleon,” an early ancestral form in the chameleon lineage. The tiny creature lacked modern chameleons’ specializations, like joined digits and compressed bodies, Daza said. But it had a curled tail and skull features that suggested it may have fed like modern chameleons, using its tongue to capture prey, he said.
According to Smithsonian.com, the lizards were caught in the resin of ancient coniferous trees some 99 million years ago, where they have remained until present day. Originally discovered several decades ago in the mines of Burma, many of the creatures remain in exceptional shape, the study authors noted, with their claws, bones, scales and toe pads all still intact.
“These fossils represent most of the diversity of lizards with a superb amount of detail,” Daza told BBC News. “We can pretty much see how the animals looked when they were alive. They provide a really nice snapshot of the past. To me it is like going back in time and doing a lizard collecting trip when we can see what these animals looked like.”