[forsnax5]

Hey, birds got thumbs! :)

[forsnax5]

One of your favorite topics, sir...

[far sider]

Oh boy, another transitional form out the window. Gee, maybe Duane Gish is right, after all.

[syriacus]

This is very interesting. Thanks. I've forwarded it to my family members, who have always been skeptical of the "birds descended from dinosaurs" theory."

[HEY4QDEMS]

My entire outlook on life will be forever altered.

[Timmy]

But . . . I thought this was settled. It 's a fact. We have proof . . .

[VadeRetro]

Feduccia gets a little "out there" in his insistence that birds and dinos are siblings, not child and parent. Here's what he's trying to make go away:

Fig. 1: Archaeopteryx	Fig. 2: Deinonychus
Fig. 3: Hoatzin chick	Fig. 4: Hoatzin adult

That's Archaeopteryx, the theropod dinosaur Deinonychus, and a modern bird (Hoatzin) that as a juvenile has a "throwback" clawed forelimb similar to fossil early birds but grows out of it to become a flying adult.

From the article:

"Whatever the ancestor of birds was, it must have had five fingers, not the three-fingered hand of theropod dinosaurs," Feduccia said.

The standard reptilian forelimb has five fingers, of course. Theropods evolved to lose two. Most scientists think birds simply inherited this same manus. In fact, this similarity was one of the lines of evidence that suggested a dinosaur ancestry for birds in the first place.

"Scientists agree that dinosaurs developed 'hands' with digits one, two and three -- which are the same as the thumb, index and middle fingers of humans -- because digits four and five remain as vestiges or tiny bumps on early dinosaur skeletons. Apparently many dinosaurs developed very specialized, almost unique 'hands' for grasping and raking.

I can't tell where the problem is. Maybe the observation of which fingers are lost on the dinosaur is wrong.

"Our studies of ostrich embryos, however, showed conclusively that in birds, only digits two, three and four, which correspond to the human index, middle and ring fingers, develop, and we have pictures to prove it," said Feduccia, professor and former chair of biology at UNC. "This creates a new problem for those who insist that dinosaurs were ancestors of modern birds. How can a bird hand, for example, with digits two, three and four evolve from a dinosaur hand that has only digits one, two and three? That would be almost impossible."

Or maybe Feduccia is seeing what he wants, not what is there. I can't tell where the problem is, but it's unlikely that the figure above is just a misleading coincidence.

[Stultis]

To keep the debate about the origin of birds in perspective, bear in mind that whether birds descended from dinosaurs (the dominant view) or whether they evolved from thecodonts (Feduccia's view) this does not change anything about the relationships of living organisms.

If birds evolved from thecodonts, so did the dinosaurs, and all other archosaurs ("ruling reptiles") including Crocodilians, which are the last surviving archosaurs, and all this happened long after archosaurs and leipedosaurs ("non-ruling reptiles") split. Therefore, whichever theory about birds is true, crocodiles are still more closely related to birds than they are to other living reptiles.

[NYer]

"It is now clear that the origin of birds is a much more complicated question than has been previously thought," Feduccia said.

Not really. Unless, of course, he's an atheist.

[beGlad]

Rather tough luck for for the unhatched ostriches.

[syriacus]

Far more likely is that birds and dinosaurs had a much older common ancestor, he said.

Should this statement make Sankar Chatterjee happy?

[Junior]

TUCvER bump.

[bert]

keep in mind the source.

Left wing wannabe scientists from the Carolina Blue zone can't be believed.

[Gladwin]

I wish there were some pictures posted somewhere of these embryos. It would clear up a lot.

http://www.ulb.ac.be/sciences/biodic/EImOiseau0002.html

Which are chicken embryo pictures. Most of the tissues don't appear differentiated. At 72 hours, you can see the spine and head starting to form, at most.