New research conducted by the collaboration between Argentinian and paleontologists from the University of Alberta adds a new piece into the puzzle that is snake evolution. The research explained that around 100 million years from now, snakes have legs however, cheekbone of snake offers critical insights about the evolution of the modern snake. The millions of years old legged reptile fossils give details into how the head of the modern snake evolved. The researchers studied amazingly well-preserved fossils of the Najash Rionegrina, a rear-limbed snake, found in Argentina. The research suggested that 100 million years back, these limbed snakes have cheekbones (jugal bone), and these bones had disappeared in their modern progenies.
Fernando Garberoglio, from Universidad Maimónides, in Argentina, is the lead author of the research. He explained that the results of the report suggest that the ancestors of the modern snakes were big-mouthed and big-bodied instead of burrowing form as considered earlier. He also explained that ancestral snakes retained their hind limbs for quite a long period before the origin of present snakes, those are for most of the parts completely limbless. Paleontologists understanding about evolution of modern snakes was hampered for decades because of limited fossils records. However, the fossils presented in this new study are critical for restructuring the initial steps in the evolutionary history of snakes.
These new findings revolutionized our understandings of cheekbones in reptiles that include snakes and non-snake lizards. Michael Caldwell is the professor in earth and atmospheric science, and biological science department is the co-author of the study. He explained we were guessing it all wrong for the past 160 years and the paper corrects this very important feature that is based on empirical evidence. The scientists examined the specimen using micro-computed tomography (micro-CT) scanning. Micro-CT is used to visualize the structures of the skull within the fossil’s specimen. It examined blood vessels, pathways of nerves, and skeletal structure. This would be impossible to see otherwise, without damaging the specimen.