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Pterosaur Takeoff

03 Mar

Pterosaurs look awkward. There, I said it. They look like they shouldn’t fly and, for a long time, people puzzled over whether they could.

The problem was that the math just didn’t add up. Birds move through the air in a specific way and it seemed obvious that this would be the natural path for evolution. The problem with applying it to pterosaurs was that these biomechanics simply didn’t work. These flying lizards were simply too large, too heavy, and too gangly. The largest pterosaurs may have weighed over 500 pounds, ten times heavier than the heaviest flying bird alive today and the biggest one, Quetzalcoatlus had a wingspan of over 35 feet. Aerodynamics aside, how did these things even get off the ground?

For a long time people answered it by suggesting that pterosaurs were only gliders, not true fliers. They would have had to live near high cliffs and hurl themselves into space to take off, severely limiting their habitats and ecology. Another idea was that perhaps the air was denser 65 million years ago (due to either atmospheric changes or a bizarre idea called the water canopy).

However, those ideas are changing now. Michael Habib is one among many paleontologists who are re-examining their assumptions and coming out with interesting new ideas. Most significantly, he isn’t using bird-based biomechanics to model flight, instead he’s going back to the basics and examining the very structure of the pterosaur body.

First of all, their method of take-off may have been quite unique. Habib’s answer lies in their overly dense, muscular arms. Far too dense for bird mechanics. Habib suggests that, instead of taking a running start like birds, it appears large pterosaurs may have taken off by hurling themselves off the ground in a spectacular catapult maneuver.

If this idea is correct, it would vastly increase the number of potential pterosaur habitats. No longer would they be restricted to sea cliffs, instead they could live and fly wherever a they could get a few yards of good clearance.

Furthermore, it turns out our ideas of their airborne abilities might have been wrong too. In a separate paper, Habib teamed up with another researcher named Witton and worked on Quetzalcoatlus. According to Habib’s calculations this gigantic animal was actually the world-champion distance flier, with an effective range of up to 12,000 miles. It could have flown halfway around the world, nonstop, in as little as 10 days! A great improvement on the cliff-restricted animals previously envisioned.

Of course, these results are still open to interpretation and discussion. Without a living pterosaur we can never know how they worked in life. However, as Kevin Paduin of UC Berkeley says, “Every time we think we’ve figured them out, they throw us another curve.” And as this idea picks up steam, more and more researchers are sure to arrive. New ideas on the physics, ecology, and behavior of pterosaurs may be right around the corner.

Sources: National Geographic Magazine, NPR, Scientific American , umpc.berkeley.edu, Witton and Habib (2010), Victorialodging.com, BBC

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2 Comments

Posted by on March 3, 2012 in Natural History

 

Tags: , , , ,

2 responses to “Pterosaur Takeoff

  1. David Esker

    September 7, 2013 at 8:57 am

    How does Superman fly? He says up, up, and away before leaping into the sky. How did the pterosaurs fly? According to Habib, like Superman they simply leaped into the sky, with the only exception being that they pushed off using all four limbs. While Habib’s explanation may seem really swell to both the paleontology experts and most ten year olds, it is not a hypothesis that stands up to scientific rigor. To achieve flight an animal the size of would need to get above its stall speed of about 18 m/s. To go from zero to 18 m/s in the approximate three meters of its leap requires an acceleration of 54 m/s2 or about five and a half g’s (a = v2/2x). To accomplish five and a half g’s it would need to use its superman’s strength while pushing against sprinters blocks to keep from landing on its face. Seriously, one has to be just as simple minded as a ten year old to believe that leaping into the sky is a valid scientific explanation of how pterosaurs flew. Now, I can be somewhat understanding to the fact that the paleontology community does not want to admit that they do not have a clue as to how the pterosaurs flew, but nevertheless their continuously propagation of ignorance is not helping to advance science. It is shameful how these paleontologists pretend to be experts when in reality nearly all of them are completely ignorant of basic physics and aerodynamic principles.

    Esker

     
  2. Phil Parsons

    September 23, 2013 at 8:07 am

    Never mind leaping to flight “with but a single bound”, it is worth remembering that with a wing-loading of 37 Kg/m2 (Henderson 2010) Quetzalcoatlus N would also have had a glide like a house-brick! As far as we know, it had a single-surface wing membrane making it even less efficient. Its wing configuration would allow it to land using a snap-stall (like a hang glider) from 40mph. But having taken on a few more Kg of food, it now needs to take off again.

    Now that it is becoming certain that this creature could not fly under the laws of aerodynamics as we know them, the idea is taking hold that in fact it was ‘secondarily flightless’. This means that it grew larger a few million years after it had decided to live on the ground and therefore grew like an Ostrich or Emu. (Why don’t they have 34ft wings?)

    Finally, the proposal from Habib that it could fly 12,000 miles non-stop in 10 days just beggars belief. That’s 50mph all day (and night) – and in a straight line! Dr Habib needs to climb back into his flying saucer…..

     

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