Quetzal

Am I misinterpreting the article, or is it saying that Microraptor had the capability for powered flight? If so, does this mean that the dinos developed flight independently twice (in the Microraptor lineage and the Archeopteryx lineage)? The Nature article states the new find had assymetrical pennaceous feathers on both fore and hindlimbs - which are supposed to have an aerodynamic function necessary for flight (vice simply gliding).

MrDarwin

Either that, or it is suggesting that other dromaeosaurs were secondarily flightless, a theory that has until now had little support. (Some paleontologists would place the origin of flight at the very base of the theropod lineage, with all those big carnivores being secondarily flightless.)

But regardless, the article suggests that feathers, but not flight, were primitive for dromaesaurs (something that has already been established by the numerous feathered but clearly flightless dinosaurs); if the right pre-adaptations were in place (feathers being the big one), "flight" could have arisen twice within the same group (although Microraptor gui is thought to have been a glider, rather than a true flier).

Here's another view: maybe some form of gliding was used by juveniles of this entire group to escape predators, but the ability lost as the animals matured and became larger. (I believe there are living reptiles--komodo dragons??--that are entirely ground-living but whose babies live in trees to escape predation.) This juvenile characteristic may have become more developed in adults of some species to eventually become true flight, but would have been much easier in the groups with the smallest adults. (And perhaps the adults, at least the smaller ones, were primarily ground-living but took to the trees to nest.)

These are really exciting times in paleontology--and it's rather amazing that fossil discoveries end up in the news so often nowadays. The field was rather moribund when I was growing up (1970s) so my early interest in fossils and paleontology gave way to other things. If I were growing up today, I would seriously consider going into paleontology as a profession.

Valentine Pontifex

It seems to me that part of this is the world being a bit more open than it used to be. A lot of these new finds are coming from areas besides North America and Western Europe which have not had people doing intensive work for centuries.

With all these Chinese fossils coming to like in the last decade I just wonder just what we would have now, what we would now know, if only Mao had actually cared about science. (Of course I would choose caring about the millions of people that could have lived if had so wished over the fossils.)

braces_for_impact

I heard an interesting program on NPR which addresses this find. Including the fact that some scientists are wary this latest four-winged find could be a fake. Apparently the prices offered in those provinces in China is enough that farmers, etc. are leaving in droves and going amateur fossil hunting.

Forgive me if these articles already address this but I haven't had a chance to read them as of yet. Apparently this find is exceptionally detailed and practically whole, which is rare indeed. Not to mention it practically looks like a mythical beastie from what I understand.

Doesn't this find basically support the school of thought that animals acquired flight originally by gliding down from the trees?

Edited for spelling

seesaw

Thanks for the link it's really interesting.

Valentine Pontifex

It has been addressed. The principle author of the research paper is the person who discoved the archaeoraptor forgery. The paper addresses this concern in its last paragraph whose last sentence reads "We carefully examined the specimens under the microscope and with high-resolution X-ray computerized tomography (CT) to test the authenticity of one of the studied specimens45 (IVPP V13352) and can guarantee the accuracy of the information that we provide in this study." The footnote is the an article is to this article on the forgery.

They also have some counterslabs for the specimens which can greatly increase confidence. When a rock is spit in two to reveal a fossil the slab hold fossil and the counterslab is the opposite piece of rock. The their have been additions the slab and counterslab will obviously not match up.

Jobar

What a remarkable looking creature. Are there any theories or opinions on why these four-winged variants lost out to the two-winged varieties? (Maybe the same reasons there are few biplanes used in modern aviation?) And when did they become extinct- are they another victim of the KT impact?

Doubting Didymus

They'd be even worse than biplanes. At least biplanes get off the ground. Do people think this feller ever even flew? He looks about as good at flying as a gliding possum to me.

Non-praying Mantis

Interestingly enough, we can see the same kind of comparison in insects. Four winged insects are usually considered "primitive," whereas most "advanced" insects have only two flight wings or merged wings.

Beetles have hardened forewings (called elytra) that probably don't contribute much to lift, most Lepidoptera and Hymenoptera have special structures on their wings that join them into one flight surface, and Diptera have only two flight wings, with the hind ones modified into balancing organs (halteres).

Four winged insects are the non-wingfolders (considered primitive) such as Odonata and Ephemeroptera, and other relatively primitive wing folders such as stoneflies.

I suspect that this pattern results from forewing-hindwing interference. The wing "wash" of the forewings probably reduces the lift (and therefore the effectiveness) of the hindwings if they beat in syncrony. Dragonflies get around this problem by not beating their wings in syncrony.

Perhaps something similar happened with dinosaurs?

NPM

Doubting Didymus

For those of you who cant tell what NPM is talking about:

Lepidoptera - butterflies and moths
Hymenoptera - ants, bees and wasps
Diptera - Flies
Odonata - Dragonflies
Ephemeroptera - Mayflies.

I suspect that the second pair of wings on this dino would have dissapeared. (this is, if this species continued to evolve into fully airborne creatures). Bats for example, would once have used two large glider style flaps between front and hindlegs. Further evolution for fully airborne flight reduced the rear flaps, and enlarged the front limb flaps into complete wings. I suspect this trend may even be typical: four winged limbs being better for gliding, and two large wings better for flight. At some point in the future, I would expect creatures like modern gliding possums and frogs to leave their 'winged' hindlimbs behind in favour of forewings. (If, that is, they evolved for flight, which is far from certain).