This demonstrates that the lower bar of the jugal was lost through snake evolution, leaving behind a rod-like jugal in modern snakes. In snakes, the jugal and the upper temporal has been lost. "After 160 years of getting it wrong, this paper corrects this very important feature based not on guesswork, but on empirical evidence." Experts previously thought that the absence of the jugal was a shared feature of all snakes, living and fossilized. The remains of the rear-limbed snake species Najash rionegrina, unearthed in Argentina, were remarkably well-preserved, revealing the presence of a type of cheek bone called a jugal bone … “This research revolutionizes our understanding of the jugal bone in snake and non-snake lizards,” said Professor Michael Caldwell, from the University of Alberta. Michael Caldwell who co-authored the study stated that the research he and his team did revolutionizes the understanding of the jugal bone in a snake. Credit: Raúl Gómez The researchers examined a strikingly well-preserved fossil of the rear-limbed snake Najash rionegrina, found in Argentina. "After 160 years of getting it wrong, this paper corrects this very important feature based not on guesswork, but on empirical evidence." “This research revolutionizes our understanding of the jugal bone in snake and non-snake lizards,” said U of A paleontologist Michael Caldwell, who was a co-author on the study. The study shows that nearly 100 million years ago, these legged snakes still had a cheekbone – also known as a jugal bone – that has all but disappeared in their modern descendants. The study reveals that the Najash lived with hind legs for 70 million years and that they were actually useful and not useless appendages. Najash. The study shows that nearly 100 million years ago, these legged snakes still had a cheekbone–also known as a jugal bone–that has all but disappeared in their modern descendants. "This research revolutionizes our understanding of the jugal bone in snake and non-snake lizards," said Michael Caldwell, study co-author and professor at the University of Alberta.
But unlike modern snakes, Najash had a jugal bone, which is akin to a cheekbone. “This research revolutionizes our understanding of the jugal bone in snake and non-snake lizards,” Caldwell, a professor at the University of Alberta, added.
"This research revolutionizes our understanding of the jugal bone in snake and non-snake lizards," said Michael Caldwell, professor in the Department of Biological Sciences and Earth and Atmospheric Sciences, and a co-author on the study. The study shows that nearly 100 million years ago, these legged snakes still had a cheekbone--also known as a jugal bone--that has all but disappeared in their modern descendants. Journal of Vertebrate Paleontology publishes on all aspects of vertebrate paleontology, such as vertebrate origins, evolution, and functional morphology. The researchers examined a strikingly well-preserved fossil of the rear-limbed snake Najash rionegrina, found in Argentina. MPCA 500 has a large jugal bone… In a typical lizard we can see the loss of the Jugal bone which frees up the quadrate and allows for a wider swing of the jaw (thus allowing the lizard to swallow larger food items). "This research revolutionizes our understanding of the jugal bone in snake and non-snake lizards," said Michael Caldwell, study co-author and professor at the University of Alberta. An artist's impression of the snake. [Mirror] ... As well as hind legs, the snake also had a cheekbone called a jugal bone - a feature that has all but disappeared in today’s modern snakes. In just one piece of work, the new findings and analyses settle a long-standing debate on the sequence of bone loss on the skull of snakes during their early evolution: the postorbital bone, not the jugal bone, was the major “cheekbone” element lost early in snake evolution, and after the disappearance of the temporal bones. The remains of the rear-limbed snake species Najash rionegrina, unearthed in Argentina, were remarkably well-preserved, revealing the presence of a type of cheek bone called a jugal bone that is absent in most modern snake species. Researchers used micro-computed tomography to image the well-preserved fossil and identify its unique components. The researchers examined a strikingly well-preserved fossil of the rear-limbed snake Najash rionegrina, found in Argentina. Argentinian and University of Alberta paleontologists add a new piece to the puzzle of snake evolution.