The world's oldest chameleons have been discovered within amber that dates back to 99 million years before our own time. Research on the ancient specimens could answer important questions in biology, investigators theorize.
Nearly 100 million years ago, a lizard walked into the resin of a coniferous tree in Myanmar. After the creature became stuck in the sticky residue, the resin hardened into amber, trapping the animal to the present day. This creature, along with 11 others like it, was found decades ago in a mine, but it was not until recently that researchers were able to analyze the specimens.
The dime-sized chameleon discovered in the amber is 78 million years older than the previously oldest-known specimen of its type. Of the 12 animals recovered in the mine, three of them - a chameleon, gecko and an archaic lizard, are the best preserved.
"These fossils tell us a lot about the extraordinary, but previously unknown diversity of lizards in ancient tropical forests. The fossil record is sparse because the delicate skin and fragile bones of small lizards do not usually preserve, especially in the tropics, which makes the new amber fossils an incredibly rare and unique window into a critical period of diversification," Edward Stanley of the University of Florida said.
Micro-CT technology was utilized to create a 3D model of the ancient creatures in order to better understand their body structure and biology.
Biologists hope that by examining the ancient specimen, they will gain a better understanding of how this group of animals evolved in the distant past.
The gecko was shown to possess adhesive toe pads similar to those found in its modern-day descendants. This suggests the adaptation dates back more than 100 million years. The archaic lizard was not yet formed into the distinctive shape of today's animals, but was adorned with the distinctive darting tongue seen in contemporary specimens. The chameleon found preserved in the amber revealed that these creatures likely did not get their start in Africa as previously believed.
The age of these animals, together with the presence of modern-day counterparts, suggests the tropics serve as an ecological refuge for species, highlighting the importance of preserving these ecosystems.
The newly-discovered species of lizard will be described and named in upcoming research.
Analysis of the ancient lizards preserved in amber was profiled in the journal Science Advances.