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Re: [Re: [Re: Feathered/scaly theropods: trying to make the point.]]
"Zoe Heraklides" <firstname.lastname@example.org> wrote:
> "email@example.com" writes:
> > It should also be noted that these bunch of "feathered" dinos all > >
came from>the exact same location; which is more than just a > >little
suspicion if you askme.
> What exactly do you imply by this? Are you saying that all the Liaoning
> theropods/birds are fakes? Or that the feathers (or structures that >
look like feathers) were added on as an artifact of preservation?
The latter; mostly. I believe that after the archaeoraptor incident, that
everyone digging for fossils out there is extremely careful of forgeries.
By exact same location I mean that _Beipiaosaurus_ _Sinornithosaurus_ &
_Sinosauropteryx_ all come from the exact same location. Each one's location
description reads like a carbon copy of the other. That all of a sudden we
would find so many "fuzzy" theropods from so many different clades and all
coming from the same locality (outside Beipiao city seemed to be the popular
description) comes off, to me as rather suspicious. I wouldnt' mind it if it
were only a few dinosaurs from the same genera or so, but to have a
theriznosaur, dromaeosaur & compsognathid all from the same place, with the
same covering (not placed anatomically; mind you) seems a little dubious.
> As has been discussed, non-theropods & non-birds from Liaoning do *not* >
show feathers: frogs, mammals, pterosaurs, ornithopods.
So I heard; I'm wondering how close to the "fuzzy" dinos they were.
> >But if it originated earlier, then how does one explain the scale
> >impressions of tyrannosaurs?
> This has also been discussed many times before. Maybe only tyrannosaur
> chicks had them, and the adults (being very large animals) lost them.
> (Remember, the fuzz on the Liaoning theropods look a lot like natal >
down in brids.)
I believe that's debatable. The pics I've seen of the specimens appear to look
more like coarse hair than natal down. In Xiao et al's description of the
feathers, they mentioned similarities to down (don't believe that they said
they "looked a lot like them" and how they were, apparently, indistinguishable
from the contour feathers seen on _Confusciornis_)
> >As for secondary featherlessness, I don't buy it. What people seem to > >
be forgetting is that scales aren't simple little structures, but > >
another form of integument. In order for the secondarily featherless > >
_Carnotaurus_ scenario to work, the animal would have had to have > > lost
one form of integument (feathers, fuzz or what have you) and > > replaced
it with another form (scales). Afterall we don't find scales > > on the skin
of plucked chickens do we? And the secondary > > featherlessness
on the legs of ostriches shows skin, not scales. So > > it would seem more
parsimonious to assume that if the animal is found > > with scales, then it
probably always had scales and didn't evolve > > them later on; unless, of
course, the aforementioned experiment with > > scutes proves to be true.
> Perhaps, in the earliest theropods with feathers, the faethers co- >
existed with scales over the body. Feathers were/are not an "everywhere > or
nothing" phenomenon. Chickens do have scales where they don't have >
feathers (e.g. feet). Then again, over 120 million years seperates >
chickens from the feathered theropods of Liaoning.
Yes, but then avians probably never evolved feathers on the feet to begin
with. As such these scutes are a hold over from a more ancient time and not a
newly evolved novelty. A better example would be in ostriches, where they have
undergone secondary feather loss on their legs and all that they have to show
for it is bare pink/white skin. No scales.
> >No doubt; these Yixian "fuzzballs" have been the hottest topic in dino
> >paleontology since the whole "birds are dinosaurs descendants" thing > >
> I'm still waiting to hear your explanation/theory.
On what; the "fuzzy" dinos? I already mentioned that I believe it could have
been contamination upon fossilization (such as dying on some plant material)
the proximity in time & space, along with the non-anatomical preservation of
this "fuzz" are what I consider evidence of this.
Oh and before anyone decides to counter with it. I do believe _Caudipteryx_
was feathered. It does, after all, preserve actual feathers and it preserves
them in an anatomic position. I'm not sure what to think of NGMC 91. It's
still new to me and is the only one of these "fuzzballs" that seems to be
>Jura - who believes all dinosaurs are scaly, until proven otherwise.
> ...Even in the face of overwhelming evidence to the contrary.
What overwhelming evidence? We have far more evidence that scales were the
"default" dinosaurian trait than we do that feathers were.
> I guess all those professional scientists who have examined and >
described the Liaoning theropods are just seriously deluded.
Welcome to the world of science; where arguments from authority mean a tad
more than squat.
Prime example: Larry Martin, Alan Feduccia and John Ruben are all professional
scientists who have looked at some of these specimens (along with the infamous
_Longisquama_) and yet there is not a single person on this mailing list who
would believe anything that they said without it being accompanied by a
dumptruck full of salt.
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