Two-Legged Fossil Indicates Snakes Evolved on Land

FoxNews.com ^ | April 19, 2006

[mlc9852]

NEW YORK — A new fossil discovery has revealed the most primitive snake known, a crawling creature with two legs, and it provides new evidence that snakes evolved on land rather than in the sea.

Snakes are thought to have evolved from four-legged lizards, losing their legs over time. But scientists have long debated whether those ancestral lizards were land-based or marine creatures.

The new find reveals a snake that lived in the Patagonia region of Argentina some 90 million years ago, said Hussam Zaher of the University of Sao Paulo in Brazil, who describes the find in Thursday's issue of the journal Nature. Its size is unknown, but it wasn't more than 3 feet long, he said in a telephone interview.

[orionblamblam]

OK. So, again, Genesis supports evolution, and thus Creationists are heretics bound straight for Hell.

[Manic_Episode]

Well, that's a spin worthy of Bill Clinton.
I'm impressed, but I impress very easily.

[Elsie]

I am SURE glad these folks are POSITIVE about what this new data means!  (Other than 'funding', of course!!)

 

Thursday, April 20, 2006

NEW YORK — A new fossil discovery has revealed the most primitive snake known, a crawling creature with two legs, and it provides new evidence that snakes evolved on land rather than in the sea.

Snakes are thought to have evolved from four-legged lizards, losing their legs over time. But scientists have long debated whether those ancestral lizards were land-based or marine creatures.

The new find reveals a snake that lived in the region of Argentina some 90 million years ago, said Hussam Zaher of the in Brazil, who describes the find in Thursday's issue of the journal Nature. Its size is unknown, but it wasn't more than 3 feet long, he said in a telephone interview.

It's the first time scientists have found a snake with a , a bony feature supporting the pelvis, he said. That feature was lost as snakes evolved from lizards, and since this is the only known snake that hasn't lost it, it must be the most primitive known, he said.

The creature clearly lived on land, both because its anatomy suggests it lived in burrows and because the deposits in which the fossils were found came from a terrestrial environment, he said.

So, if the earliest known snake lived on land, that suggests snakes evolved on land, he said.

Little new evidence had appeared in recent years in the land-versus-sea debate, he said, and "we needed something new. We needed a new start. And this snake is definitely a new start for this debate."

While the creature still had two small rear legs, it crawled like a modern-day snake, he said. It probably used its legs only on occasion, though it's not clear for what, he said.

The creature, named Najash rionegrina, is "a fantastic animal," said Jack Conrad, a researcher at the American Museum of Natural History in New York and co-curator of an upcoming exhibit on lizards and snakes.

"It's really going to help put to rest some of the controversy that's been going around snake evolution and origins," he said. Conrad said he never took sides in the land-versus-sea debate, but "but this is starting to convince me."

Olivier Rieppel, a fossil reptile expert at the in Chicago, called the find important and said Najash is clearly the most primitive known snake.

If snakes did evolve on land rather than the sea, their fossil record might be less complete because early fossils would have been better preserved in a marine environment, he said.  (So much for HUMAN fossils!)

That, in turn, suggests "we may not know all the lineages of early snake evolution," he said. Maybe several snake lineages lost the legs of their lizard ancestors independently, he said.

The creature's name comes from a Hebrew word for "snake" and the province of Argentina, where the discovery took place. 

[hail to the chief]

I believe that was a jab at the common creationist argument with the same wording.

[Ken H]

Two-Legged Fossil Indicates Snakes Evolved on Land

Which begs the question, what do two-legged trousers indicate about trouser snakes?

[JCEccles]

It's simply amazing what miracles darwinists are able to account for when the law is employed to ensure that only the darwinist party line is allowed to be uttered.

Any scientific theory so weak that it requires protection by the the ACLU and the federal courts is an joke and an abomination.

[Old Professer]

What does a snake look at all day, anyway?

[Old Professer]

The mercury thermometer was invented 282 years ago, it began to be widely used by civilized people about a hundred years later; I have two thermometers on my refrigerator top (catch-all), one outside (WalMart junk), a digital lying wall thermostat, an outside air sensor on my wife's Buick, my home page is the local T.V. weather page, another thermometer rests on a shelf over the washing machine and I still can't get the barometer, hygrometer, thermometer console to match any of the rest.

Where I grew up, if snakes had legs they would have been cut off and cooked up for supper.

[Doctor Stochastic]

Polar bear (and other arctic animal) hunting range.

Length of growing seasin.

Aggrate glacer melting (over many glaciers.)

Northward drift of warm-water fish.

[mlc9852]

"Any scientific theory so weak that it requires protection by the the ACLU and the federal courts is an joke and an abomination."

LOL - I never thought of it that way. But you are absolutely right!

[dartuser]

These articles are always filled with "it is supposed that ... it might suggest ... its believed that ... " language. Thats not the point. As long as several scientists agree that things COULD have happened that way, and as long as it fits in the Darwin model ... they can slap a "truth" sticker on it.

[LIConFem]

I thought those spurs had something to do with procreation (or the attempt). I had a Ball python for about 5 years, and that's what the vet told me.

[Elsie]

That it's hard to run with them down!?

[spetznaz]

I thought those spurs had something to do with procreation (or the attempt). I had a Ball python for about 5 years, and that's what the vet told me.

You are correct in that they are useful during mating, but they are vestigial upper-leg bones. Here is an excerpt:

Q: Do snakes have legs? I heard on the Discovery Channel that they have little bitty legs, like nubs. Is this true?

A: Primitive snakes — such as, pythons and boa constrictors — do have nub-like legs beneath their skins and tiny, half-inch claws that protrude out above the nubs but nestle close to their bellies near the anus. Actually, even the nubs are not legs but rather a remnant of upper-leg (thigh or femur) bones. The males still use the spurs — but only during courtship and fighting — not to walk.

It turns out that the python Hox genes fail to activate pathways (the apical-ridge and polarizing-region paths) that signal normal limb development. So growth stops. The hind limb bud lacks "key signaling proteins," says Carroll, describing Cohn and Tickle’s discoveries. This activation failure may "stem from changes in Hox gene expression that occurred early in snake evolution," say Cohn and Tickle.

[LIConFem]

Neat. Thanks for the clarification!