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Re: MORE "Dinosaur Planet"dinosaurs!!!(This time with feathers)



--- John Bridgeman wrote:
>
>I was under the impression that "Dave" specimen
> was one of the best evidence in favor of feathered 
> dinosaurs,since it could be the most undeniably
>classified as a dinosaur,unlike the much more 
> birdlike Caudipteryx or even Microraptor.
>

I'd like to contradict in that if Gregory Paul's secondarily flightless 
'protoavians' hypothesis is correct, then maniraptorans (including NGMC 91) and 
ornithomimosaurs would be a avians.  Probably the least birdlike feathered 
dinosaur is Sinosauropteryx, which may be even more basal than the 
Coelurosauria (Longrich, 2002).

>
> I refer you to www.dinodata.net to the listing 
> for the genus Microraptor.In the section on M.gui,
> it states: "The integumentation of M.gui is
> based on the holotype and referred specimen...."
> Unless I have misinterpreted something,it should 
> say "The integumentation of M.gui displays 
> two types plumulaceous and pennaceous feathers 
> with a length of...." without saying that it is
> based on the holotype and referred specimen.Using
>  that term implies that it was not part of the 
> original fossil,but reconstructed based on
> other,similar specimens.
>

The page most likely was referring to the interpretation of how the 
integumentary structures should have look was based on the holotype and 
referred specimen. Also, the holotype is the specimen on which a species is 
founded, so therefore, the holotype of Microraptor gui, is in fact the original 
fossil. I see nothing on the page that should imply it was reconstructed, 
you've simply misunderstood.

>
> Strangely enough,you have already listed for
> bird features than dinosaur for Caudipteryx.
>In common with oviraptorsaurs you list five 
> characters in common.Then you list overall 
> around ten features in common with various 
> groups of birds.(I agree that Caudipteryx does
> not belong to the same group of advanced birds
>as Confuciusornis.)
>

You've misunderstood Mickey's post. Mickey pointed out what was invalid with 
the characters used by Feduccia et al. to support an avian relationship for 
Caudipteryx. To reiterate what Mickey said, the characters are either: 1- 
shared with oviraptorosaurs; 2- unknown due to lack of relevant material in 
Caudipteryx; 3- based on circular reasoning; or 4- not present in Caudipteryx.  
Mickey only listed three valid characters supporting a Caudipteryx + Aves 
relationship (fewer dorsal vertebrae; reduced third manual digit; and extremely 
shortened tail).  However, the first two characters are found in birds more 
advanced than Confuciusornis. Caudipteryx lacks at least eight characters found 
in both Confuciusornis and advanced birds, so the two characters shared between 
advanced birds and Caudipteryx must be convergences. And the lack of characters 
shared between Aves and Caudipteryx indicates that Caudipteryx is obviously not 
a bird.

So Mickey's overall challenge remains. In order to support an Aves + 
Caudipteryx relationship, you must produce valid characters that do not fit 
into the four categories above.

>
> I would'nt say that my viewpoint is highly 
> flawed,as it is all a matter of
>interpretation of the evidence.

I would say it is highly flawed considering all the problems addressed by 
Mickey with it. Yes, it is a matter of interpretation of the evidence, and in 
this case, there's a right way, and there's a wrong way.

===

Nick Gardner
Aim s/n Eoraptor22


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