Sorry, it has nothing to do with duplicitous talking serpents hanging out in fruit trees.
"Extraordinary skull fossil reveals secrets of snake evolution" |
The Conversation (https://theconversation.com/extraordinary-skull-fossil-reveals-secrets-of-snake-evolution-127307)
Quote(https://images.theconversation.com/files/302601/original/file-20191120-542-aoxqd4.jpg)
An artist rendition of the najash snake
Image Credit: Michael Caldwell/Alessandro Palci
On very rare occasions, an exceptional fossil is unearthed that provides an extraordinary glimpse into the evolution of a group of organisms.
This time, it is the beautifully preserved skull of an ancient snake with rear limbs, Najash rionegrina. Our study of this fossil has been published in the journal Science Advances (https://advances.sciencemag.org/content/5/11/eaax5833).
This and other new fossils help answer longstanding questions on the origins of snakes, such as how they lost their limbs and evolved their highly specialized skulls.
Najash rionegrina is named after the legged biblical snake Nahash (Hebrew for snake), and the Río Negro Province in Argentina, where the fossils were discovered. Fossils of Najash are about 95 million years old, and were first described in Nature from a fragmentary skull and partial body skeleton that preserved robust rear limbs (https://www.nature.com/articles/nature04413).
This rear-limbed fossil snake garnered a great deal of media interest as it followed earlier reports of fossil marine snakes with rear limbs (https://www.nature.com/articles/386705a0). What made Najash unique was that it was a terrestrial snake living in a desert, not an aquatic snake living in the ocean. In addition, the fossils were not compressed flat by the weight of overlying sediments, and so they were preserved in three dimensions, unlike the fossil marine snakes.
[. . .]
A longstanding hypothesis is that snakes evolved from a blind, burrowing lizard ancestor. A group of small, worm-like, small-mouthed burrowing snakes, known as scolecophidians (https://onlinelibrary.wiley.com/doi/abs/10.1002/mmnz.20020780108), have long been considered to be the most primitive living snakes.
The new Najash fossil material shows that the skulls of that lineage of ancient snakes were nothing like those of scolecophidian snakes. Instead, Najash and its kind had large mouths with sharp teeth and some of the mobile skull joints that are typical of most modern snakes. However, they still retained some bony skull features of more typical lizards.
In evolutionary terms, Najash tells us that snakes were evolving towards the skull mobility necessary to ingest fairly large prey items, a landmark feature of many modern snakes.
[Continues . . . (https://theconversation.com/extraordinary-skull-fossil-reveals-secrets-of-snake-evolution-127307)]