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Re: "Elaphrosaurus" gautieri identified as an ......



Mickey Mortimer (Mickey_Mortimer111@msn.com) wrote:

<A few other comments-  The posterior dorsal doesn't look very procoelous
to me, perhaps indicating "E." gautieri is more primitive than Patagonykus
and mononykines.  The caudal centra have lateral fossae or pleurocoels,
resembling Patagonykus.  The humerus lacks the highly divergent internal
tuberosity of Patagonykus and mononykines, also suggesting it is more
primitive than these taxa.  Though the pubis could be propubic as
Lapparent presumedly interpreted it, reverse which way is anterior and it
is similar to Patagonykus'.  Either way, it doesn't matter, as the
condition in basal alvarezsaurids is unknown and the boot otherwise
resembles a good plesiomorphic type such as ornithomimosaurs. The pubic
symphysis is said to be oval, perhaps indicating it's reduced as much as
Patagonykus.  The presence of any symphysis shows it is not a mononykine. 
The hindlimb elements are very slender, and the greatly expanded distal
tibia seem to be an apomorphy of the taxon. Any comments?>

  Well, while this is such an intriguing hypothesis, I pull open what
Lapparent published on the taxon, and his figures, and I see that I must
concur with Tim on the nature of the humerus: it is impossible to tell how
long it is without a middle section. The humerus otherwise appears to lack
much of an internal tuberosity, buit it may be broken, and the ent- and
ectepicondyli are very, very short. The tibia is apparently shown with the
proximal end in side view, and the distal end in cranial view. This shows
both a short cnemial crest that is elevated, not angled ventrally for
forward, a short fibular crest, a shallow and short tibial incisure, and
no distinct fossa for the reception of the ascending process of the
astragalus above the ventral edge, which shows it may have been less than
50% the width of the distal end in height. Otherwise, this taxon looks
pretty generic with some features questionably associating with
*Elaphrosaurus*, but nothing that tells me this is _not_ a ceratosaur,
ableisaur, a non-tetanuran, or so forth. It does seem to lack the distal
tibia of anything tetanuran or avetheropodan.

  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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