Ancestors of Birds Had Four Wings

We have looked at the final solutions so far of nature and flight. However, they had to have a beginning somewhere. There were two theories about how flight evolved around the time of dinosaurs. The first was that flight evolved from dinosaurs running very fast, and then eventually became more and more aerodynamic, and finally took to the skies. This was the ground-up theory. The other one was that flight evolved from the tops of trees down. That gliding came first, and then over time powered flight was achieved. In 2003 a new fossil was found that would eventually decide what theory was correct.

The fossil was that of the Microraptor. This unique creature had feathers, but maintained some of its dinosaur looks.  It had a wingspan of about one meter, and weighed only 1kg (2.2lbs). The interesting thing was that this animal had two sets of wings. With this extra set of wings it was debated whether they were used for powered flight, or if they were simply for gliding. A study found that the four wings were actually physically incapable of powered flight.  They concluded that it could only glide, and that the Microraptor would glide over 40 meters.

The same study found that  if the Microraptor was to jump from a tree, it would have to land on another tree, because it would not have survived if it hit the ground. It seems that the debate has been concluded. Flight started with animals gliding from one tree to the next.

Soon after the Microraptor there was a shift in evolution from four wings to two wings. However, the Microraptor is believed to still be an ancestor of the modern birds.

Sources:

6 Comments

Lorena Barba posted on October 18, 2011 at 12:55 pm

Hi Nathan,
You address a topic that was often hinted at during class (especially when we had the guest speakers, who were biologists), and that is the question of how flight evolved. I have become very intrigued by this while working on this course!

David Villari posted on October 19, 2011 at 1:39 pm

Isn’t it curious that the dragonfly (similar with four wings) is such a well adapted flyer, yet the Microraptor was only capable of gliding? It goes to show that even with similar designs there are so many more complexities to the actual act of with flying.

Shahil Patel posted on October 19, 2011 at 6:07 pm

I wonder why the microraptor could only glide and not fly, but dragonflys can fly!

Lorena Barba posted on October 20, 2011 at 7:24 pm

You can get “The Four-Winged Dinosaur” on Netflix!! :-) —unfortunately not on instant play, though :-(

Lorena Barba posted on October 20, 2011 at 7:36 pm

It looks like the Microraptor was an evolutionary step between gliding between trees, and actual flying. At least that is what the article that Nathan links to seems to be saying.

Lorena Barba posted on October 20, 2011 at 7:48 pm

I found it on YouTube!
http://youtu.be/yL0UIzU0EEc