Mar
19
2009

Dinos of a feather: New fossil discoveries throw the origin of feathers into confusion.  Or possibly Confucian.
Dinos of a feather: New fossil discoveries throw the origin of feathers into confusion. Or possibly Confucian.Courtesy treehouse1977

Science has known for a while that birds evolved from dinosaurs. We’ve discussed this before on Science Buzz, particularly here and here.

Now a new fossil has emerged from China that is complicating the picture. Tianyulong confuciusi was a small, two-legged plant-eater that lived in northeastern China about 130 million years ago. Its recently-discovered fossil included clear signs of feathers. This is nothing unusual—lots of dino fossils, especially from this part of China, have feathers.

What is unusual is that Tianyulong is not related to any previously known feather-bearing dinosaur. Not even remotely. All previously know dino feathers come from theropods, the two-legged meat-eaters like T. rex. Tianyulong was a type of hadrosaur—sometimes known as a “duck-billed dinosaur.” And the last time hadrosaurs and theropods shared a common ancestor was 230 million years ago!

This discovery raises several intriguing possibilities:

1. Perhaps feathers evolved very early in dinosaur history, far earlier than we now suspect. If the very first dinosaurs had feathers, then all other dinosaurs could inherit them, even after the various branches of the dino family tree split up and went their separate ways. But if that’s true, then why have we not found feathers on more dino skeletons?

2. Perhaps feathers evolved twice—once in the theropods, and once in the hadrosaurs. That would be pretty unusual. Right now, there seems to be no information on whether these new feathers are very similar to previously-known feathers, or completely different.

3. One thing has always bugged me about the whole bird-dino link. All dinosaurs fall into two major groups: those with hips shaped like those found in modern lizards, and those with hips shaped like those found in modern birds. But all the previous bird-like features, including feathers, come from the lizard-hipped group. Seems odd to me that nature would evolve bird-like hips twice. Maybe—just maybe—birds evolved from the bird-hipped dinosaurs.

Now, there’s tons of other evidence besides just hips to link birds to theropods, so nobody is going to be re-writing the bird family tree any time soon. All we can do is keep our eyes peeled for more interesting discoveries.

Your Comments, Thoughts, Questions, Ideas

Brittany_Todd's picture
Brittany_Todd says:

I'm sure there's many species that have not been officially discovered. Just think of how much of the rainforest and the oceans that have yet to be studied!

Good article, but I'm sure there will be many more like this to come :)

★BRITTANY ☠BONES☠ TODD★

posted on Wed, 04/22/2009 - 6:39pm

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