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Re: Quo vadis, T. rex? [long]
At 08:18 PM 2/6/96 -0500, Jeff Poling wrote:
>At 04:40 PM 2/6/96 -0700, Jeffrey Martz wrote:
>>> Why? Right now there are damn few skin impressions of theropods that can
>>> conclusively show anything. Absence of evidence is not (necessarily)
>>> evidence of absence. Given that 1) Dromaeosaurs were very closely related
>>> to Archaeopteryx and 2) Archaeopteryx had feathers it makes sense that all
>>> maniraptorans had feathers.
>> Why? You are assuming that feathers evolved in the common ancestor
>>of all maniraptorans. It could just have easily have been a later
>>innovation of one small group, which eventually led to Archaeopteryx.
>>Its largely a question of when feathers first appeared, something that is
> That's right. It could just have easily been a feature of
>archaeopterigians, rather than the common ancestor of maniraptorans.
>However, what you said in your first post was "Assuming that any theropod
>except Archaeopteryx had feathers is a much bigger assumption" implying that
>that one theory carried more weight than the other.
> In any case, until _Pelicanimimus_ is fully described and put through
>peer review, I think it looks more likey that at least the common ancestor
>of ornithimimids and maniraptorans, rather than just the common ancestor of
>maniraptorans, had feathers or were well on their way to it.
> It just crossed my mind that since pterodactyls had hairlike structures,
>maybe proto-feathers are plesiomorphic for archosaurs....
...and, of course, another reason why, in my mind, it's likely that they
all had feathers is the question of insulation on the smaller dinos.
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