Science Advances published the result of a research on March 04, 2016. The article describes the study of 12 lizard fossils preserved in burmite. The authors of the study are Juan D. Daza1, Edward L. Stanley, Philipp Wagner, Aaron M. Bauer and David A. Grimaldi.
The researchers assessed 12 lizards preserved in amber from Burma. 10 of them are housed in the amber collection at the American Museum of Natural History and the other two at the Museum of Comparative Zoology. The scientists placed the age of the burmite around 100 million years ago. All the subjects come from the Kachin Province in Myanmar.
3 of the lizards are very well preserved. 2 of them retain most of their bone structures and skin, but there is one perfectly preserved. The last one marveled scientists since even the organs are intact. In the article, the team said how difficult is to find small fossils in this shape.
“Amber deposits are especially useful for preserving small, delicate organisms that are seldom represented as lithified remains or, as fragmentary microvertebrate elements, are often overlooked. This is critical because most lizards are small-bodied, and small size has been suggested as a feature that has led to the diversification and success of this group” the article reads.
The fossils are already giving a lot of new information to the scientists, especially on geckos and chameleons. The fossilized geckos have adhesive toe pads which mean that the species got their traits earlier than thought. As for chameleons, the lizards reveal a long projectile tongue used to catch their prey. However, many characteristics of modern day chameleons were not found in the fossils which make scientists think the fossils come from a sister specimen.
Some of the species found among the fossils no longer inhabit tropical regions which mean that many lizards might have established in Mid-Cretaceous in tropical regions. The chameleon stem, for example, is among the 100 million-year-old pieces which sets its origins much older than previously recorded.
The scientists used High-resolution x-ray computed tomography to analyze every lizard. They included a supplementary video with 3D volume – rendered movies of some of the fossils. They also said that additional data will be made available to authors by written request. The team also phylogenetic analyzes because there is an ongoing conflict between the morphological and molecular phylogenetic hypotheses in scaled reptiles.
The pieces were purchased from excavation dealers from the town of Myitkyina. These are the oldest lizards preserved in amber to the date.
Source: Science Advances Magazine