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Re: Microraptor hanqingi, new species from China.
evelyn sobielski <firstname.lastname@example.org> wrote:
> In and by itself, this is not necessarily absurd. Both trains of evidence may
> be correct without colliding - any arboreal form that should happen to
> descend from a cursorial-terrestrial form would necessarily evolve through a
> stage in which well-developed cursorial plesiomorphies coexist with
> crude arboreal apomorphies, and the material evidence *could* be interpreted
> thus in this case.
Granted. But Gong &c do not interpret _Microraptor_ in this way.
They regard _Microraptor_ as a sprawling quadruped incapable of
terrestrial/bipedal locomotion. I find this very difficult to
> The hypermelanism also argues for a hot-and-humid environment and possibly
> life under a closed canopy. So, the time and place are right for an
> experiment in arboreality. But this does *not* mean it was an *arboreal*
> animal, at least if you don't assume natura facit saltus.
Yes, I agree. A small theropod could venture up into vegetation
without qualifying as "arboreal". This is one reason why the
arboreal-versus-terrestrial dichotomy is so unhelpful.
> However, that would require to accept the fact that "avoids" (I would write
> "para-avians" but this is too close to Paraves for comfort) all
> descended from small cursorial-terrestrial theropods. There is nothing to
> suggest that early archosaurs evolved towards arboreality, while early
> reptiles did so vigorously and early enough (they started off very, *very*
> small and used low woody growth as it seems) to require an entirely
> different critter to result by _Microraptor_'s time. Something that had the
> bauplan of a chameleon or _Draco_ perhaps. Not sprawling, but
> positively splayed.
There were large columnar plants around, even if they were not true
"trees". The Late Permian anomodont _Suminia_ has been interpreted as
an arboreal herbivore. Permian-Triassic diapsids like _Longisquama_,
_Sharovipteryx_, drepanosaurs, and coelurosauravids were most likely
But I suspect the erect/bipedal bauplan of _Microraptor_ and other
paravians was not so much due to differences in vegetation compared to
earlier times (although this could have been a factor), but to the
ancestry of paravians from among obligate terrestrial bipeds. For a
creature that still spent most of its time on the ground, and only
occasionally ventured into 'trees", there was no reason to abandon its