This is an unprecedented discovery that allows the scientific community to understand the evolution of lizards in the history of the world. Researchers have studied the fossil of a lizard trapped in Burmese amber over 110 million years ago. To this day, it remains the oldest Cretaceous fossil ever discovered by scientists and helps trace the origin of lizards.
This species of lizard named Retinosaurus hkamtiensis was subjected to the analyzes of a scanner which resulted in a clear 3D representation. This lizard is the first complete representative of a set of lizards placed in the category of scincoideans. They are made up of armored lizards and nocturnal lizards.
This discovery is a game-changer when it comes to the geographical traces of the origins of lizards.
Unpublished information on their morphology
The specimen discovered in Burma shows resemblances to the xantusiides modern. Common characteristics that make scientists say that the Retinosaurus hkamtiensis lived in cryptic areas like rock crevices and under logs.
Researchers are particularly amazed by the morphological similarities concerning the arrangement of the scales and other organs of the body of the lizard to that of the xantusiides. The researchers were also able to distinguish fragile eyelids from Retinosaurus hkamtiensis which differ from those of modern nocturnal lizards, which have fused scale-like eyelids.
“We had the rare opportunity to study the articulated skeleton, but also to describe the external appearance of the lizard (scalation), in the same way that herpetologists (specialists in amphibians and reptiles) study modern species. »
Juan Diego Daza, associate professor in the Department of Biological Sciences at Sam Houston State University and co-author of the study
On the controversy over the origin of lizards
The discovery of this ancient lizard fossil in Asia leads scientists to believe that the lineage lizards are not native to North and Central America. This revives the eternal and thorny question of the origin of known animal lineages belonging to the Cretaceous. Researchers have put forward geological hypotheses in this direction.
“The Burma (now Myanmar) microplate was probably not part of Asia when our lizard lived. At the time, the area may have been an island that split off from Australia and traveled northwest. »
Dr Andrej Čerňanský from Comenius University and his colleagues