Thursday, May 19, 2011

Dinosaur Science

Dinosaur Science
Conditions had to be just right for dinosaurs to leave fossilized footprints
"Well DUH discoveries" have to be corroborated with evidence, even if they sound too simple to require it.
BBC: In a paper published in the Journal of the Royal Society Interface, Peter Falkingham of the University of Manchester and his collaborators explain why fossilized dinosaur footprints are so rare. According to the group's computer simulations, the massive prehistoric animals left enduring prints only in thick, shallow mud. Lighter dinosaurs would not leave prints in the same kind of mud, which means that the absence of small prints next to large fossilized prints should not be taken as evidence for the absence of small dinosaurs.
Research team finds extinction evidence
Volcanoes kill Permean sealife
A University of Calgary research team has found evidence of what caused the world's biggest extinction 250 million years ago which set the stage for dinosaurs to evolve.

Stephen Grasby, adjunct professor of geoscience at the U of C, said his team focused on the causes of the Permean extinction, the largest extinction in the history of the earth which wiped out up to 95 per cent of life in the sea and 70 per cent on land. The extinction was caused by a volcanic eruption, burning coal and greenhouse gases.

"There was a series of bad events at this time," Grasby said. "Coal burning, runaway global warming, lots of stresses on the environmental system dumping toxic ash into the oceans."

The team of researchers found layers of coal ash in the Canadian arctic which had traveled from volcanoes in northern Russia.

"We showed the first direct evidence of layers of coal ash at sites of eruptions," he said. "It's a double whammy, not only having a big volcanic eruption, but also combusting a huge amount of coal."

The extinction did see the production of greenhouse gases, though on a much larger scale than what may exist today.

According to U of C geoscience professor and Grasby's colleague on the study, Benoit Beauchamp, research like this can warn of the potential end results of releasing large amounts of carbon dioxide.
New Dinosaur: Titanic Triceratops Ancestor?


Meet what could be the new granddaddy of horned dinosaurs—Titanoceratops.

At 15,000-pound (6,800-kilogram) the prehistoric titan would have rivaled the African elephant-size Triceratops, which weighed more than 11,000 pounds (5,000 kilograms), according to a new analysis of a partial skeleton.

The beast—which had an 8-foot-long (2.4-meter-long) skull—is the biggest dinosaur found so far in North America during the late Cretaceous period, about 74 million years ago.

If indeed a new species, Titanoceratops' discovery could also mean that triceratopsins—members of a family of giant horned dinosaurs—evolved their gigantic sizes evolved at least five million years earlier than previously thought, the study says.

Triceratops would have evolved into a separate species after Titanoceratops had died out, according to the study.

"It's pretty surprising—I would have not have thought something this big and this advanced was living in this time period," said study leader Nicholas Longrich, a paleontologist at Yale University.

But other experts say the skeleton is not complete enough to call it a new species.

"I would like it to be real," said Michael Ryan, curator of vertebrate paleontology at the Cleveland Museum of Natural History.

"[But] until we find a better specimen ... there's no reason to say it isn't a Pentaceratops," a similar type of horned dinosaur.
What's cool is my "buddy" Dr. Michael Ryan, the curator of vertebrae paleontology the Cleveland Museum is quoted in the article. I almost met Dr. Ryan (which is a cool name) when I was at the museum, but he was away. I'm a big fan of "Paleoblog," which I've taken off my blog list for some reason. Perhaps I should put it back up!

Dinosaurs may have survived longer than previously thought
I think I've reported on this before, but ...
A new technique to date dinosaur bones developed by a University of Alberta researcher may prove that dinosaurs lived up to 700,000 years past previously recognized extinction dates.

The results challenge the view that dinosaurs died out in a relatively short period, around 65.5 or 66 million years ago. It means the idea of one huge meteorite wiping out the dinosaurs may need a radical revamp.

"It's still possible that a meteorite or a series of meteorite impacts in a one- or two-million year period around that time did cause enough devastation to really stress animals like dinosaurs. But it wasn't an instantaneous event," explained Larry Heaman, the researcher behind the testing technique.

The researchers took a fossilized femur of a sauropod and, using a new urianium isotope dating method, found that it yields a date of only 63.9 – 65.7 million years ago, meaning this particular dinosaur was alive up to 700,000 years after the mass extinction event.

Heaman collaborated with US Geological Survey researcher James Fassett, who has been trying for nearly three decades to prove some dinosaurs lived past the Cretaceous-Tertiary Boundary, a worldwide sediment layer enriched in meteorite materials that traditionally marks the demise of the dinosaurs.

Although some dinosaur bones have been found physically above the Cretaceous-Tertiary Boundary, in a period called the Paleocene, most palaeontologists believed that they had simply been washed out from older sediments and re-deposited with younger ones.

"All these hints that this [fossil-bearing layer] is Paleocene have been met with controversy and skepticism. This is really the first direct dating that supports it," Heaman said.

The new technique has previously been used to date ancient minerals, but this is the first time it has been used on bone. Its success lies in the ability to image and select specific areas that are suitable for dating. Heaman acknowledged that because it is so new, it will no doubt be met with some uncertainty.

Heaman first dated an older bone that was bounded by two volcanic ash layers that have very well defined dates, and found that the ages agreed. This helped prove the veracity of the technique, but Heaman says there is still ways to improve the technique, which he is trying to do on other dinosaur fossil samples.

No comments: