A fossil of `` footed snake '' 95 million years ago overturns the theory of evolution



The skull of the “footed snake” that lived 95 million years ago was found in excellent condition. This discovery denies the belief that snake ancestors have so far, and a new hypothesis has emerged.

New skulls and skeletons of the Cretaceous legged snake Najash, and the evolution of the modern snake body plan | Science Advances
https://advances.sciencemag.org/content/5/11/eaax5833

Extraordinary skull fossil reveals secrets of snake evolution
https://theconversation.com/extraordinary-skull-fossil-reveals-secrets-of-snake-evolution-127307

Snakes had back legs for 70 million years before losing them, new fossil shows-CNN
https://edition.cnn.com/2019/11/20/world/snake-evolution-hindlimbs-scn/index.html


Najash Lionegrina ” is a “snake with legs” whose existence was first clarified in a paper published in 2006. In the excavation at that time, the bones of the hind legs were found along with the fragmented skull about 95 million years ago. Najash attracted media attention not only in the desert like many snakes, but also in the ocean.

Snake researchers understand that snakes evolved from lizards and that the skull played a major role in that evolution, but since only a fragmented skull was found in 2006, snake heads I didn't understand the whole situation. For this reason, a newly discovered skull in a solid state is very important for revealing the evolution of snakes.


Fernando Galvelogrio, who was a student at the University of Buenos Aires, excavated in Argentina, and paleontologist Sebastian Apestegia, who were excavated in Argentina.


A hypothesis that has been supported for many years is that snakes are said to have evolved from small blind lizards who lived in pits, and it is said that mekra snakes are the most primitive among them. However, the newly discovered Najash fossil has a different lineage from the snake. Najash has a large mouth lined with sharp teeth, and some of the joints move like a modern snake. On the other hand, there are some features in common with typical lizard skulls.

In terms of evolution, the new Najash fossils show that snake bones have evolved to swallow and digest large prey.

In addition, the cheekbone behind the existing snake eye was thought to be derived from the retroorbital bone of the lizard ancestor, but the newly discovered skull denies this possibility Both researchers say. “The new Najash specimen is a good example of science's' predictability '. The presence of cheekbones in snakes supported and supported the researchers' predictions, and the old hypothesis was wrong The new hypothesis was recognized, 'the researcher commented.

From Najash's skull, it is believed that the snake ancestors were close to large lizards like the Komodo dragon . In addition, until now it was thought that the snake with legs was only a transitional period until it adapted to the figure without legs, but this research also showed that it had legs for 70 million years It is.

in Science,   Creature, Posted by logq_fa