Birds and Velociraptor?

[jomes]

I don't understand how most popular literature can state that Velociraptor and Deinoychus are the closest know relatives of birds. Correct me if I am wrong (I am a zoologist interested in dinosauria; not a paleontologist) but, didn't birds evolve in the mid-to-late Jurassic? To my understanding, in the late Cretaceous, birds were already flying around and being birds. How can an animal derive its ancestry from a creature it itself is older than? To me, it makes no sense that the last of the Dromaeosaurids evolved into birds. The Dromaeosaurids may have descended from a creature that gave rise to both birds and themselves, but they were not birds. They were dinosaurs. Wouldn't a late Cretaceous bird like Hesperonis be the closest relative to existing birds?

It's like saying humans gave rise to the lemurs. We evolved from the same stock, but humans took a different path.

Jomes

P.S. Lemurs are pretty damn cool in their own right. Not real bright, but pretty cool anyway.

[Thorondor 33]

Good post.

And I don't see anywhere where you say dinosaurs were feathered. ;D

[jomes]

Thank you, but I am looking for an answer, not a pat on the head. I feel my question is a valid one. People who make their living studying extinct life have purposed that late Cretaceous animals gave rise to Jurassic stock. I am not the smartest man in the world, but that makes no sense. How can an educated scientist make such a ridiculous statement? How can this become arguable fact in books? Is there really a media bias over such a discredited argument? People interested in Dinosauria are probably not the Earth was created in seven days kinda folks. The bones(at least the ones I have seen) do not show what has become absolute fact. My question is, "Why has this become publishable truth with such weak evidence?" Where are the unbelievers? Only here? I want the truth.

Jomes

[Señor Pilty]

1. Yes, there is a media bias for the "birds are dinosaurs" argument. Every time a dinosaurologist who supports the dino-bird link publishes a purported 'study' [sic], it gets in the New York Times. However, any study that debunks this theory is only very briefly noted, if at all, in some obscure journal that not even the dinosaurologists seem to read.

2. The Jurassic-Cretaceous time disparity is indeed one reason why many ornithologists find the idea that birds are maniraptorans preposterous. That is why the dino-bird people resort to computerized cladistic studies, since the actual bones show the reverse--there is no way velociraptor, with its great clawed forearms, could have given rise to hummingbirds.

3. It is accepted by the dinosaur community because of peer pressure; because of the desire to look 'hip' and 'avant-garde'; because, truth be told, many dinosaurologists haven't actually been trained in scientific methodology; because saying "birds are dinosaurs" gets one in the newspapers and on cable documentaries; because of the need for PhD students for theses papers; i.e. nothing to do with 'scientific research.'

By the way, there is a member of this forum who is a professional paleontologist, who can answer your questions better; I should probably quit before I am overwhelmed with cladistic terminology I can't understand ;D Since you're a zoologist you can answer his arguments better than I can

[Señor Pilty]

*Previous post redacted till I am of a more even temper* Feathered dinosaur talk always makes my blood boil ;D That dinosaurs and birds shared a common ancestor is not in dispute, but the dinosaurs early on split from the bird lineage, and any similarity between raptors and birds is due to parallelophyly.

This whole birds are derived raptors nonsense began when John Ostrom noticed similarities between deinonychus and birds. Bob Bakker subsequently really ran with this idea and expanded it into the "birds are warm-blooded dinosaurs" hypothesis. Apparently he hasn't heard of convergent evolution. Most ornithologists are quite firm that birds could not have descended from the dromeosaurs. There are actually numerous differences underneath the superficial similarities.

[Señor Pilty]

And thanks for posting jomes. It just goes to show that what passes for "scientific fact" in dinosaurology is insufficient for other disciplines like zoology

PS Lemurs are indeed cool I like them better than primates and monkeys ;D

[tomhet]

jomes, I will post your... well... post ;D in another forum, I hope that's alright with you.

dinotoyforum.proboards100.com/index.cgi?action=display&board=dinos&thread=50&page=11

[Thorondor 33]

Jul 29, 2008 20:23:46 GMT -5 Señor Pilty said:

PS Lemurs are indeed cool I like them better than primates and monkeys ;D

I agree.

[dinotoyblog]

Here I am to save the day! ;D

I don't understand how most popular literature can state that Velociraptor and Deinoychus are the closest know relatives of birds.

Its because they are.

Correct me if I am wrong (I am a zoologist interested in dinosauria; not a paleontologist) but, didn't birds evolve in the mid-to-late Jurassic?

Probably even earlier.

To my understanding, in the late Cretaceous, birds were already flying around and being birds. How can an animal derive its ancestry from a creature it itself is older than?

Birds did not derive ancestry from Velociraptor and Deinonychus, they share COMMON ancestry.

To me, it makes no sense that the last of the Dromaeosaurids evolved into birds.

correct. Thats why nobody is saying that 'the last' Dromaeosaurids evolved into birds.

The Dromaeosaurids may have descended from a creature that gave rise to both birds and themselves, but they were not birds.

Exactly.

They were dinosaurs.

subjective classification. See the rest of this thread - this common ancestor was almost certainly feathered. why? Becasue primitive dromaeosaurid dinosaurs like Microraptor are preserved with fossil feathers. Plus, thee is evidence for integument in dinosaurs even more basal than dromaeosaurs.

Wouldn't a late Cretaceous bird like Hesperonis be the closest relative to existing birds?


Yes, but you originally said 'birds', not 'existing birds'. That's a big difference. (moving goalposts)

It's like saying humans gave rise to the lemurs. We evolved from the same stock, but humans took a different path."

It would be, and you would have a brilliant point - IF your argument was not a Staw Man logical fallacy (I love spotting fallacies in arguments ).

From wikipedia:
"A straw man argument is an informal fallacy based on misrepresentation of an opponent's position.[1] To "set up a straw man" or "set up a straw man argument" is to describe a position that superficially resembles an opponent's actual view but is easier to refute, then attribute that position to the opponent"

(edited version)

[dinotoyblog]

Come on guys! You have to give me some credit for this one -
It's a TEXT BOOK example of the Straw Man fallacy.

[Señor Pilty]

Sorry dinotoyblog--it has been indeed claimed that birds evolved from the deinonychosauria. From Philip J. Currie in the Complete Dinosaur:

"Dromeosaurids and troodontids, sometimes incorrectly included in a single taxon referred to as the Deinonychosauria, are more likely avian ancestral stocks. Both families are represented by well-preserved skeletons from Lower Cretaceous rocks, and Late Jurassic dromeosaurid and troodontid teeth have also been reported."

Since the book was published quite a long time ago, perhaps the scientific consensus has altered, likely because of the 'feathered dinosaurs' [sic] [sick] ;D 'discovered' in Liaoning, but I'm sure many popular and children's books haven't yet reflected the shift in nuance of velociraptors being a direct ancestor of birds to sharing a common ancestry with birds.

[dinotoyblog]

You almost had me...
But he specifically said "the last" of the dromaeosaurids.
Whether the common ancestor (something like Microraptor but more primitive) would be classified as a bird or a dinosaur (dromaeosaurid) is subjective.

[Señor Pilty]

That birds and dinosaurs share a common ancestor I suppose is not in dispute; when, how, where, and why the birds branched out is I believe the crux of the debate. I'm hoping it happened before the evolution of feathers in the Avialae ;D