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Re: Jehol in Nature
An exceptionally preserved Lower Cretaceous ecosystem
ZHONGHE ZHOU, PAUL M. BARRETT & JASON HILTON
The article includes a mention of _Microraptor_:
"_Microraptor_, another Jehol theropod with true feathers, is the smallest
known dromaeosaurid (trunk length approximately 50 mm). It exhibits several
pedal characteristics that have been suggested as potentially consistent
with a climbing/perching mode of life, whereas other features of the
skeleton demonstrate that it was not a volant or secondarily flightless
animal. The discovery of this possibly arboreal dromaeosaurid has
contributed to the debate over the origin of flight, and has been cited as
evidence for the now heterodox view that flight originated from the trees
down (by gliding and jumping down from trees), rather than from the ground
up (by running and leaping for prey)."
I would hesitate to characterize the trees-down model for the evolution of
avian flight as "heterodox". The idea that small theropods, including the
ancestors of birds, may have been arboreal was gaining momentum long before
the discovery of _Microraptor_.
"However, detailed functional morphological studies on _Microraptor_ have
not yet been attempted and are needed to test its proposed arboreal mode of
The original description of _M. zhaoianus_ included a comparison of its
pedal proportions with other taxa for the purpose of functional anatomy.
Further, the discovery of _M, gui_, with its four "wings", would appear to
shift the burden of proof why this genus was *not* arboreal.
Also in the article...
"The presence of feathers in _Caudipteryx_ and _Protarchaeopteryx_ has been
dismissed as a vestige of secondary flightlessness, and the identification
of these structures as integumentary features has been questioned, but these
interpretations have not been supported by other studies. Phylogenetic
evidence demonstrates emphatically that these animals were primarily
flightless non-avian theropods, not secondarily flightless basal birds,..."
No mention of the peculiar notion that feathered dromaeosaurids ("raptors")
were flightless birds too, and not theropods at all (a la Czerkas, Feduccia,
&c). I call this notion "Raptors Are Birds In Disguise" - or RABID for
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