South American Giant Lizzard!

[Onhell]

Dinosaur skeleton unearthed in Argentina

By MICHAEL ASTOR, Associated Press Writer Mon Oct 15, 7:38 PM ET

RIO DE JANEIRO, Brazil - The skeleton of what is believed to be a new dinosaur species — a 105-foot plant-eater that is among the largest dinosaurs ever found — has been uncovered in Argentina, scientists said Monday.
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Scientists from Argentina and Brazil said the Patagonian dinosaur appears to represent a previously unknown species of Titanosaur because of the unique structure of its neck. They named it Futalognkosaurus dukei after the Mapuche Indian words for "giant" and "chief," and for Duke Energy Argentina, which helped fund the skeleton's excavation.

"This is one of the biggest in the world and one of the most complete of these giants that exist," said Jorge Calvo, director of the paleontology center at the National University of Comahue, Argentina. He was lead author of a study on the dinosaur published in the peer-reviewed Annals of the Brazilian Academy of Sciences.

Scientists said the giant herbivore walked the Earth some 88 million years ago, during the late Cretaceous period.

Since the first bones were found on the banks of Lake Barreales in the Argentine province of Neuquen in 2000, paleontologists have dug up the dinosaur's neck, back region, hips and the first vertebra of its tail.

"I'm pretty certain it's a new species," agreed Peter Mackovicky, associate curator for dinosaurs at Chicago's Field Museum, who was not involved with the discovery. "I've seen some of the remains of Futalognkosaurus and it is truly gigantic."

Calvo said the neck alone must have been 56 feet long, and by studying the vertebrae, they figured the tail probably measured 49 feet. The dinosaur reached over 43 feet tall, and the excavated spinal column weighed about 9 tons when excavated. One neck vertebra alone measured more than 3 feet high.

Jeff Wilson, an assistant professor of paleontology at the University of Michigan, who was asked to review the finding, said he was impressed by the sheer amount of skeleton recovered.

"I should really try to underscore how incredible it is to have partial skeleton of something this size," Wilson said in telephone interview. "With these kind of bones you can't study them by moving them around on the table; you have to move around them yourself."

"It shows us the upper limit for dinosaur size," Wilson added. "There are some that are bigger but they all top out around this size."

Patagonia also was home to the other two largest dinosaur skeletons found to date — Argentinosaurus, at around 115 feet long, and Puertasaurus reuili, 115 feet to 131 feet long.

Comparison between the three herbivores, however, is difficult because scientists have only found few vertebrae of Puertasaurus, and while the skeleton of Futalognkosaurus (FOO-ta-long-koh-SOHR-us) is fairly complete, scientists have not uncovered any bones from its limbs.

North America's dinosaurs don't even compare in size, Mackovicky added in a phone interview. "Dinosaurs do get big here, but nothing near the proportions we see in South America."

The site where Futalognkosaurus was found has been a bonanza for paleontologists, yielding more than 1,000 specimens, including 240 fossil plants, 300 teeth and the remains of several other dinosaurs.

"As far as I know, there is no other place in the world where there is such a large and diverse quantity of fossils in such small area. That is truly unique," said Alexander Kellner, a researcher with the Brazilian National Museum and co-author of the dinosaur's scientific description.

http://news.yahoo.com/s/ap/20071015/ap_on_sc/giant_dinosaur



Thought it might be of interest given the current trivia question

 

[Mmm...Donuts]

I have to admit, I've been a dinosaur nut my whole life, and I honestly believe that there may be super big suckers larger than any found now. Considering that those that were found  were giants already, and they did have some notable predators like Carnotaurus and Giganotosaurus, what if in some parts of the world where sauropods had not that much predators, who knows how huge they flourished. Though I would freak out if one specimen will outdo a fairly large container ship.

 

[Onhell]

And it wouldn't be by much either, I think that as big as they did get, you can only get so big before you crumble under your own weight.

 

[Anonymous]

We shouldn't not forget that we usually only know of one specimen of many of those super-huge dinos, and that usually has only one or two bone fragments to tell the tale. So, while it may be possible to reconstruct the lizard to a certain degree, old Charlie tells us that there is always the possibility of mutation; I wonder how many of those separate species actually are just one-offs of a common type. I'm sure many palaeontologists don't even want to think about it, since the "biggest dinosaur ever" is sure to bring some cash flow.

 

[Invader]

True, but very unlikely.  If you look at how few (relatively) specimens we've found, what are the chances that even one of them is a mutation?  Mutation isn't exactly a common phenomenon.

 

[Onhell]

Perun might be on to something. After all, the article does mention that dinos that size are mostly found in South America, specifically the Argentina/Brazil region.

 

[Mmm...Donuts]

Maybe though there were diverse predator and prey species in that region, the boon in size may be from lack of disasters or diseases? Or isolation 

 

[Anonymous]

Mutation isn't exactly a common phenomenon.

Time for some basic evolutionary biology. I had my final exam in that subject in June '04, so I'm a bit rusty, and I'm sure one of our real biologists could shed more insight to this, but I'll do my best.

Try to imagine a herd of dinosaurs. For the sake of it, lets say they are apatosaurus. In biological terms, this herd is called a population. This herd is made up of a number of individual specimens, each of which carry with them an individual set of genes. Those genes are almost entirely identical, because they are related to each other- each specimen could theoretically, if each generation's genes would remain intact, be traced to one set of parents. From that perspective, the herd is also called a gene pool.
As I said, each individual has almost identical genes, or else we wouldn't have a herd of apatosaurus, but a wild mix of various different dinosaurs. Still, each individual will have a tiny little abnormality in its genes. It comes with the job. Such an abnormality would lead to a slightly longer neck, bigger feet, or maybe something that is so insignificant it is practically invisible*. Such an abnormality is called a mutation. In a big population, or a population that has steady interaction with other populations, this is not so much a problem. A mutation would die out within a few generations, because the individual specimen have plenty of other specimen from different families to mate with. The apatosaurus would remain largely the same over time.
However, if we have a small and/or isolated population, the individuals don't have much of a choice whom to mate with, so chances are that at some point, two specimen with a similar mutation will mate. Let's say they have a longer neck; their kids have longer necks too. Hence, after a few generations, we have a complete population of apatosaurus who have longer necks, resulting in, what could after even more generations, be a new species.

Another thing that could happen is that all of the sudden, the apatosaurus population is caught in an area which has higher trees than the species was originally accustomed to. To put it simple, most apatosaurus will die because their necks are too short and they won't reach the leaves. Only a few survive, because mother nature has granted them a longer neck. They survive, mate, and again, we have what would become a new species.

As you can see, mutations are not only very common, but they are the driving motor of evolution. You could also say: No mutation = No evolution.


Now, what I was trying to say is, of course that big lizard could be an individual species. But it might as well be a random-generation mutation which had no specific advantages or disadvantages over other specimen of its population, so the mutation died out again quite soon. Since we have no living dinosaurs to observe, we won't know.


__________________________
*If that is too abstract, try imagining a group of people. They all look different. Why? And why did the members of the Hapsburg dynasty, who preferred to marry among themselves, all have this spectacularly ugly lower jaw, the so-called "Hapsburg lip"?

 

[Onhell]

Damn, you learn something new everyday

 

[Onhell]

Since we already have this dino thread here is some more interesting news!

Double Trouble: What Really Killed the Dinosaurs

Charles Q. Choi
Special to LiveScience
LiveScience.com Mon Nov 12, 7:55 AM ET

Instead of being driven to extinction by death from above, dinosaurs might have ultimately been doomed by death from below in the form of monumental volcanic eruptions.

The suggestion is based on new research that is part of a growing body of evidence indicating a space rock alone did not wipe out the giant reptiles.

The Age of Dinosaurs ended roughly 65 million years ago with the K-T or Cretaceous-Tertiary extinction event, which killed off all dinosaurs save those that became birds, as well as roughly half of all species on the planet, including pterosaurs. The prime suspect in this ancient murder mystery is an asteroid or comet impact, which left a vast crater at Chicxulub on the coast of Mexico.

Another leading culprit is a series of colossal volcanic eruptions that occurred between 63 million to 67 million years ago. These created the gigantic Deccan Traps lava beds in India, whose original extent may have covered as much as 580,000 square miles (1.5 million square kilometers), or more than twice the area of Texas.

Arguments over which disaster killed the dinosaurs often revolve around when each happened and whether extinctions followed. Previous work had only narrowed the timing of the Deccan eruptions to within 300,000 to 500,000 years of the extinction event.

Now research suggests the mass extinction happened at or just after the biggest phase of the Deccan eruptions, which spewed 80 percent of the lava found at the Deccan Traps.

"It's the first time we can directly link the main phase of the Deccan Traps to the mass extinction," said Princeton University paleontologist Gerta Keller.

Clues in other life forms

Keller and colleagues focused on marine fossils excavated at quarries at Rajahmundry, India, near the Bay of Bengal, about 600 miles (1,000 kilometers) southeast of the center of the Deccan Traps near Mumbai. Specifically, they looked at the remains of microscopic shell-forming organisms known as foraminifera.

"Before the mass extinction, most of the foraminifera species were comparatively large, very flamboyant, very specialized, very ornate, with many chambers," Keller explained. These foraminifera were roughly 200 to 350 microns large, or a fifth to a third of a millimeter long.

These showy foraminifera were very specialized for particular ecological niches.

"When the environment changed, as it did around K-T, that prompted their extinction," she added. "The foraminifera that followed were extremely tiny, one-twentieth the size of the species before, with absolutely no ornamentation, just a few chambers." As such, these puny foraminifera serve as very distinct tags of when the K-T extinction event started.

The researchers found these simple foraminifera seem to have popped up right after the main phase of the Deccan volcanism. This in turn hints these eruptions came immediately before the mass extinction, and might have caused it.

Double trouble

Both an impact from space and volcanic eruptions would have injected vast clouds of dust and other emissions into the sky, dramatically altering global climate and triggering die-offs. Keller's collaborator, volcanologist Vincent Courtillot at the Institute of Geophysics in Paris, noted upcoming work from her collaborators suggests the Deccan eruptions could have quickly released 10 times more climate-altering emissions than the nearly simultaneous Chicxulub impact.

Keller stressed these findings do not deny that an impact occurred around the K-T boundary, and noted that one or possibly several impacts may have had a hand in the mass extinction. "The dinosaurs might have faced an unfortunate coincidence of a one-two punch—of Deccan volcanism and then a hit from space," she explained. "We just show the Deccan eruptions might have had a significant impact—no pun intended."

Although paleontologist Kirk Johnson at the Denver Museum of Nature and Science called these new findings "significant," he noted a great deal of evidence connected a single massive impact with the K-T extinction event. He suggested that advances in radioisotope dating could now hone down when the Deccan eruptions occurred to within 30,000 to 65,000 years. "That could help put to bed some of the disputes regarding the issue," he said.

Keller and her collaborator Thierry Adatte at the University of Neuchatel in Switzerland detailed their findings Oct. 31 at the annual meeting of the Geological Society of America in Denver.

http://news.yahoo.com/s/livescience/20071112/sc_livescience/doubletroublewhatreallykilledthedinosaurs