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Re: four winged Archaeopteryx
Kris (email@example.com) wrote:
Tim, don't get your feathers ruffled... No need to get defensive. I mean
I wasn't aware I was being defensive. But thanks for the reassurance.
I think you are making 2 very bad assumptions. One is that if any
integument is preserved, then all aspects of the integument for the animal
are thereby represented.
No, I wasn't making this assumption at all. I was very careful to avoid
making this assumption.
And second, if a region is feathered on one, and naked or scaled on
another, this region is reflective of the whole of the animal...
Isn't this the same assumption as the first one?
I can't remember, are the tubercular epidermal impressions located
everywhere on the _Juravenator_? [snip] Anyway, hopefully you aren't saying
that there is no possible way _Juravenator_ could have had feathers.
Here's what Gohlich and Chiappe (2006) have to say...
"Thus, the absence of feathers in _Juravenator_, a taxon otherwise nested
within feathered coelurosaurs, is noteworthy (Fig. 4). The extent to which
feathers covered the body of these
non-avian dinosaurs is not well known for some taxa ... The fact that
_Juravenator_ lacks any evidence of feathers in portions of integument
otherwise feathered in these coelurosaurs indicates that these animals may
have differed greatly in the extension of their feathery covering. However,
the role of ontogeny and seasonality in the development of the plumage of
these dinosaurs remains uncertain, and the possibility cannot be ruled out
that feathers evolved more than once or became lost in taxa such as
That sums it up for me.
And your comment about birds not being found in Solnhofen has absolutely
NOTHING to do with
what I was saying... That was waaaaay off the mark.
I don't think it's at all off the mark. Neornithean birds, as far as it is
known, show no evidence of losing their feathery body covering through
natural selection. But things may have been different for their non-avian
cousins, back in the Mesozoic. It is impossible to frame an evolutionary
scenario that explains the distribution of feathers in non-avian Theropoda
without invoking either multiple losses or multiple gains of feathers for at
least part of the body.
Also, don't forget that _Juravenator_ may have been very close to the origin
of feathers - and it might even lay outside the feathered theropod clade (if
Compsognathidae is paraphyletic). Thus, it could be primitively
If logic follows, what you are saying about compsagnathids and pterosaurs
living in tropical >Germany (that being, they didn't have feathers or hair
because of the weather)
Well, it was only a suggestion...
Also, most desert mammals and all desert birds, have the need for hair and
feathers (besides flying)... and the HOT climate is one of the major
I thought it was the cold desert nights.
And one more thing, it looks like this discussion of the presence of
integument on a fossil has to do a lot with taphonomy...
That's hard to disagree with.