Re: Coelophysis *feathers*???

["Waylon Rowley" <hot__male60@hotmail.com>]

To Rob Gay:


> No, no. Some people think that all dinosaurs are decended from birds, and I 
> feel this is wrong. I feel that some "theropods" were probably descended 
> from "birds" (e.g. oviraptosaurs), but most were probably not. I just feel 
> that "feathers" might be basal, and birds adapted these "feathers" into 
> true feathers.

Don't ask me why, but I also feel that the Oviraptorosauria are 
avian....just a gnawing suspicion. The palate in 'em looks pretty birdy to 
me, and then you have the pygostyle of Nomingia (thanks Mickey for the 
details on N.!!!!)....which ?might be homologous to a primitive avian 
pygostyle? But I figure it's more likely that they are simply off-shoots 
near the base of avialae.

> Not to put too much feeling into this, but I think this person is entirely 
> wrong. How can time not count? You can't be older than your ancestors? 
> People say that birds descended from dromeosaurs...but there are 0 
> dromeosaurs known from before the late Jurassic! Time is very important.

I'm not too sure about the relationship of dromaeosaurs to troodontids after 
the description of Microraptor zhaoianus, but they seem to be fairly close 
to eachother. So, if we have Borogovia and Palaeopteryx in the LJ, the split 
with dromaeosaurs must have been earlier. I've also heard that dromaeosaur 
teeth have been found from the EJ of Antarctica (just a rumor I guess, but 
it could be more).

> I am waiting for this paper to come through on interlibrary loan. Then I 
> will be able to make a more informed descision.

Got a ref? I'd like to take a look too.

> And I fully belive that there were no feathers in ornithopods, sauropods 
> and >fully grown< _C. sasteri_ and _C. nasicornis_ specimens.

I'm a believer in parsimony. If there is no good reason to believe in it, 
and no evidence for it, then it probably didn't exist. Not that i'm "stuck 
in my ways" or anything, but all it is (for now) is a fanciful idea with no 
scientific backing. But so were Greg Paul's feathered dino portraits. At 
least now we have some clue to feather distribution within dinosaurs. BTW, 
is there ANY evidence for non-coelurosaur tetanuran scutes?


> However, this does not preculde either display feathers on the skull (as 
> you posited for _Tyrannosaurus_), or down (which I think is likely) on 
> young animals. As far as I know, we have no infant specimens of either of 
> these animals, and even if we did, the areas in which they lived would most 
> likely not preserve these feathers if they did. I am hoping that soon we 
> will find an early Jurassic/late Triassic deposit much like the ones now 
> being explored in China. This will answer many questions (hopefully!) about 
> bird evolution.

ah, a cockatoo-like T.rex head would be something else, eh? Maybe they even 
had primary feathers on their lil arms for ritual display....fanning them 
out to scare off or intimidate other rexes (I read a post where someone 
actually restored a T. rex with an arm like that).


> Maybe, maybe not. After all, pterosaurs had a similar "fuzz" on their 
> bodies, and they are not very close to _Eoraptor_. Maybe "fuzz" is more 
> basal than we think. Either that, or for some reason, pterosaurs evolved it 
> too, around the same time for no apparent reason. Also, you would think 
> that scutes would preserve in a place like Ghost Ranch, were you get very 
> nice preservation of specimens. There are no scutes known from Ghost Ranch, 
> as far as I know (although it is possible that _Dilophosaurus_ may have had 
> large dermal scutes).

Hmmmm, how complex is a strand of hair? As far as I know, it's just an 
elongated scale/scute with a follicle. A structure that simple could evolve 
convergently among many taxa, so is of doubtful use in figuring out if we 
have fluffed-up basal dinos.

> Besides, who likes fluffy monsters? :)<
> Hehehe, true. Although a 42 foot long _T. rex_, with huge feathers flying 
> from it's neck would scare the crap out of me!

Yeah.....I would run too, LOL!
_________________________________________________________________
Get your FREE download of MSN Explorer at http://explorer.msn.com