By Agence France-Presse
PARIS -- A Japanese researcher has put paleo-biologists in a flap by suggesting pterosaurs -- the winged lizards beloved of toymakers and dino movies -- were unable to fly, New Scientist says.
Katsufumi Sato of the University of Tokyo carried out an unusual study on the Crozet Islands, in the southern Indian Ocean, to test flying ability among large sea birds.
He attached accelerometers the size of AA batteries to the wings of 28 birds from five large species, including the wandering albatross, the world's biggest flying bird.
Albatrosses fly by riding shifting winds, thanks to wings spanning 3.5 metres (11.4 feet) whose shape can be varied to exploit each draft.
When there is no wind, or if the wind blows at a constant speed, the bird can only stay aloft by flapping its wings, otherwise it is forced down by gravity and air resistance.
In a months-long experiment, Sato's instruments showed that the seabirds had two flapping speeds -- fast for taking off, and slow, for keeping aloft when the wind dies, New Scientist says.
The bird's flapping speed is limited by its muscle strength, and the speed decreases for heavier birds that have longer wings, Sato found.
According to Sato's calculations, animals heavier than 40 kilos (88 pounds) would be unable to flap fast enough to fly in zero winds.
A wandering albatross is fine, as it weighs 22 kilos (44 pounds) -- but the news is pterrible for pterosaurs. Large ones would be unable to stay aloft, by this benchmark.
The largest pterosaur specimen found, Quetzalcoatlus northropi, had a wingspan of 11-12 metres (35.75-39 feet) and its weight is estimated to be in the order of 100 kilos (220 pounds).
Sato presented his results at a Biologging Science Symposium in Stanford University, California last month.
He has run into flak from pterosaur fans who are convinced that their creatures were "dynamic soarers" like the albatross and could sustain active flight and not just glide.
Differences in anatomy, physiology and environment must be taken into account when comparing the two sets of flyers, they say, according to the New Scientist report.
Recently in Paleontology Category
INQUIRER.NET executive editor Leo Magno visits The Field Museum for a close encounter with "Sue," the world's most complete Tyrannosaurus rex skeleton. Sue was named after Sue Hendrickson, the American paleontologist who discovered the skeleton.
SO, did the T-rex taste like chicken, heh :)
If you've read or watched "Jurassic Park," then you've heard the hypothesis that birds evolved from dinosaurs. But researchers now have unearthed new evidence of the evolutionary link between dinosaurs and birds.
Here's an excerpt from one of the stories that came out about the Tyrannosaurus rex fossil:
When the researchers compared those amino acid sequences to those of similar proteins in several contemporary animals, they found that the T-rex sequence had similarities to those of chickens, and to a lesser extent frogs and newts. That finding bolsters a recent and controversial proposal that birds and dinosaurs are evolutionarily related, and change that hypothesis to a theory, the researchers said. "Most people believe that birds evolved from dinosaurs, but that's all based on the architecture of the bones," said John Asara, who is director of mass spectrometry at Beth Israel Deaconess Medical School. "This allows you to get the chance to say ‘Wait, they really are related because their sequences are related.' We didn't get enough sequences to definitively say that, but what sequences we got support that idea."Meanwhile, if, like me, you've wondered how the heck T-rex could have gotten up again if it fell down, considering how itty-bitty its arms were, an expert shares the answer in Scientific American. Here's an excerpt:
It is now clear that T. rex's hands could not reach its mouth. The elbow could not be extended much beyond a 90-degree angle. The arms were very strong (perhaps capable of curling nearly 400 pounds) but had a very limited range of motion, both side-to-side and up-and-down. The wrists were considerably weaker and do not seem suited for supporting large mechanical loads. Like those of their albertosaur "cousins," the small T. rex arms were often broken during life. This fact suggests that they were poorly suited for whatever the dinosaurs were trying to use them for and, more importantly, that these animals could go without using their arms for periods of up to a month.
