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



Jaime A. Headden wrote-

>   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.

>From the figure, yes, but don't you think Lapparent had some reason to
describe the humerus this way?  Or was it just wishful thinking on his part?
Trying to make "E." gautieri more distinctive than it would be otherwise?

> 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.

It's possible the proximal tibia is in medial view, but it also resembles
some tibiae in cranial view, such as Avimimus.  One would hope Lapparent
knew theropods well enough to orient the tibial ends correctly, he did use
dotted lines to connect it to the distal tibia (indisputably in
cranial/caudal view).  I don't see a fibular crest, the incisura tibialis
would be mostly hidden, its extensiveness indeterminable.  The edge of the
ascending process is only certain medially, where it extends
proximolaterally.  It's certainly possible that it was limited medially, but
expanded laterally, like mononykines.

> 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.

Then explain which ceratosaurs have deep dorsal neural canals (over 40% of
central height) and procoelous caudal centra that are keeled ventrally, even
assuming Lapparent is wrong about the humerus.  And which Elaphrosaurus-like
characters would you be referring to?

Mickey Mortimer