2
$\begingroup$

This week's podcast of the BBC's Science in Action includes a section by Rory Galloway (12:20 to 18:30) covering the Dinosaurs of China exhibit currently hosted by Wollaton Hal at the University of Nottingham, and includes an interview with curator Dr. Adam Smith.

The exhibit is of highly detailed dinosaur fossils from Liaoning, China where detailed feather structures were well preserved and have been analyzed in great detail.

One section caught my attention:

Rory Galloway: "The similarity between dinosaurs and birds was far more than superficial though. Eventually a branch of small, theropod dynosaurs evolved into the birds that fly around today. But curator Adam Smith says, if we concentrate on flight alone, it gets quite difficult to know exactly which branch of the dinosaurs actually became our birds."

Adam Smith: "Flight is really important and that’s why it evolves many times. Some of the earliest flying dinosaurs, such as the microraptor actually had four wings, not two."

The Wikipedia article on the Microraptor is quite long and includes a lengthy, technical discussion on just how these four wings might have been used. It seems that it is (currently) generally believed that these dinosaurs had the capability of powered flight, and that they could actually take off from the ground, rather than climb trees, jump, and simply glide.

This is with four wings.

There are many variety of insects with four wings and the two pair are used in a variety of different ways. But these dinosaurs are much larger, of the order of a kilogram.

Question: Have there been any complete simulations of the mechanics of four-winged dinosaur flight, showing how the wings would have been used to take off from the ground and gain altitude? A movie or animation of the coordinated flapping of the front versus rear pair of wings would be great. These days the numerical models and computing power are within reach, but it would still be a substantial effort, so I'm not sure if this has been done yet or not.

I'm assuming that this is not currently believed to be the branch of dinosaur that eventually evolved into modern birds, but it's a fascinating branch nonetheless.

below: from here.

enter image description here

$\endgroup$
  • 1
    $\begingroup$ "The similarity between dinosaurs and birds"... that sentence burned my eyes. This is exactly as saying "the similarity between mammals and primates". The fact that he is just a journalist should not be an excuse, because he is a science journalist. $\endgroup$ – user24284 Jul 9 '17 at 4:37
  • 1
    $\begingroup$ @GerardoFurtado then avert your eyes and relax! In biology, the word "similarity" does not have a precise definition as it does in mathematics. It's perfectly fine to address the similarities and differences between any two things. If you have not listened to the entire segment, 12:20 to 18:30, I'd invite you to do so now, and put the quote back into context as any scientist would. :) $\endgroup$ – uhoh Jul 9 '17 at 4:51
  • $\begingroup$ @Gerardo Furtado: No, it's the same as "the similarity between mammals and reptiles". $\endgroup$ – jamesqf Jul 9 '17 at 5:33
  • $\begingroup$ Apparently both you guys didn't understand it: "birds" is a group inside "dinousaurs". Therefore, the sentence makes little sense, since all birds are dinosaurs. Again: such a sentence is just like "the similarity between vertebrates and frogs", or "the similarity between plants and ferns". You are comparing A with B, however, B is a smaller group contained inside A. That being said, what @uhoh said ("It's perfectly fine to address the similarities and differences between any two things") doesn't apply here, because one of those things (birds) belong to the other thing (dinosaurs)... $\endgroup$ – user24284 Jul 9 '17 at 7:00
  • 1
    $\begingroup$ Related: biology.stackexchange.com/questions/17546/… $\endgroup$ – ukemi Jun 4 at 10:17
5
$\begingroup$

Note nowhere in the article does it mention the rear wings flapping. The rear wings do not provide lift, they are acting as control surfaces to improve stability and maneuverability. (think of the tail of a plane).earlier/proto flies have far more demand for control surfaces than developed/derived fliers due to lacking more precise control of flight surfaces.

They basically take off just like any other bird, if they could fly. Flight in dinosaurs likely did not even evolve from gliding as we commonly think of it but instead from raptorian pouncing, the sprawled posture of microraptor you sometimes see, with its hind legs spread wide, is anatomically impossible, you literally have to dislocate both legs to do it. Dinosaur hip joints do not allow for much lateral extension unlike mammalian or varanid ones, more like a hinge than a ball and socket.

The animal in flight would have looked like this.

enter image description here

Hall, Justin, et al. "A new model for hindwing function in the four-winged theropod dinosaur Microraptor gui." JOURNAL OF VERTEBRATE PALEONTOLOGY. Vol. 32. 325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA: TAYLOR & FRANCIS INC, 2012.

$\endgroup$
  • 1
    $\begingroup$ Thank you for setting me straight on the flapping! Searching on the title of Hall et al. immediately gives oodles of open access further reading; ((almost) all pdfs) 1, 2, 3, 4, 5, 6... $\endgroup$ – uhoh Jul 9 '17 at 7:05
  • 2
    $\begingroup$ The actual original source was part of a conference so all that was physically published was an abstract as part of the conference issue of JVP. This quirk pops up occasionally in paleontology because there are not that many of us and the Society of Vertebrate Paleontology yearly conference is big enough to cover a significant portion of us. So the feeling is if you are interested you will go. There has been talk for years of recording putting the full talks up online but the cost has been a major delay. Like always the media likes the strangers less accurate interpretation. $\endgroup$ – John Jul 9 '17 at 14:55
4
$\begingroup$

There is a good attempt at a simulation of 4 winged flight of Microraptor on BBC's Planet Dinosaur.

There's another Planet Dinosaur video about their venomous teeth and hunting tactics.

And a Microraptor locomotion video on Attenborough's Conquest of the Skies (Sky 3D).

$\endgroup$
1
$\begingroup$

Several models have been proposed, challenged, and revised over the past two decades:

A previously published reconstruction shows that the hindwing of Microraptor supported by a laterally extended leg would have formed a second pair of wings in tetrapteryx fashion. However, this wing design conflicts with known theropod limb joints that entail a parasagittal posture of the hindlimb. Here, we offer an alternative planform of the hindwing of Microraptor that is concordant with its feather orientation for producing lift and normal theropod hindlimb posture. In this reconstruction, the wings of Microraptor could have resembled a staggered biplane configuration during flight, where the forewing formed the dorsal wing and the metatarsal wing formed the ventral one.

$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.