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Re: Query: Epidendrosaurus=Scansoriopteryx?



Luis Rey (luisrey@ndirect.co.uk) wrote:

<I agree that many times the reversed hallux is an artifact of
preservation. In this case (however) what I saw in the fossil made me
doubt. It was  clear and articulated, and the 'curled' opposable fourth
toe was longer than many I have seen.  It was also clearly not a
dromaeosaur, but that is already acknowledged. I still have my doubts...
have you seen the fossil itself?>

  I have not seen the specimen in person, only published and unpublished
photos. The toe appears to be non-articulated in some views, but in the
type of Epidendro, the toe is either medial (not retroverted) or cranial
(heterodactyle). The first phalanx is very long and the
metatarsal-phalangeal joint is very close to the second digit's,
suggesting to me that the possibility of opposability is likely. Note, I
do not say "reversed," because I entertain the possibility, as does Tracy
Ford, that the first toe was often mobile in many theropod dinosaurs, and
likeliest indeed in most avepectorans and eumaniraptorans. *shrug*.
Middleton's study is an interesting adaptive study, but it can only
circumspectly be applied to fossils without some clearly locked indication
of the mtI's position, and that of the phalanges to it. Most mtIs in
theropods lack a ginglymoid or semi-ginglymoid distal articular surface,
suggesting the digit could rotate axially in life; one would need to
identify the distribution of ligamental pits in the distal mtI to show
which taxa could rotate their digits and to which degree.

  Cheers,

=====
Jaime A. Headden

  Little steps are often the hardest to take.  We are too used to making leaps 
in the face of adversity, that a simple skip is so hard to do.  We should all 
learn to walk soft, walk small, see the world around us rather than zoom by it.

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