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Re: WHAT IS ELOPTERYX?



>From: darren.naish@port.ac.uk
>Organization: University of Portsmouth
>To: dinosaur@usc.edu
>Date: Mon, 22 Nov 1999 13:27:23 GMT0BST
>MIME-Version: 1.0
>Subject: WHAT IS ELOPTERYX?
>CC: darren.naish@port.ac.uk, jrhutch@socrates.berkeley.edu,
> m_troutman@hotmail.com, qilongia@yahoo.com
>Priority: normal
>
>On the mysterious _Elopteryx nopscai_, John Hutchinson wrote..
>
>> "Elopteryx" is commented on by Csiki and Grigorescu in Oryctos 1,
>> who regard it as a non-diagnostic maniraptoran.
>
>I've played with all of the 'Elopteryx' material and my impression is

>that the femora (BMNH A1235 and A1234) are avian; however, I must
>confess I've seen hardly any dromaeosaur stuff. There is
>certainly a cranial intermuscular line in A1235 which looks just like

>that of birds (its angle is about the same as that seen in
>ratites)... but does the structure look the same in non-birds like
>dromaeosaurs?

Yes, the cranial intermuscular line appears to be an archosaurian synapomorphy, more on that when it's finally published (probably 18 months, ugh). I confess that I have not seen Elopteryx and so my comments will be minimal. I have seen lots of basal birds and other maniraptorans, so I can comment on them and published descriptions of Elopteryx. I agree with Darren -- based on an intuitive approach, I would place my bet on its bird-itude, but more associated and diagnostic material is needed to nail it down for sure, of course.

>I have good notes and diagrams on the 'Elopteryx' femora and I do not

>recall a structure that I interpreted as a posterior trochanter. Has
>anyone identified such in these femora? The femora certainly are
>quite strange: in A1234 the crista trochanteris and greater
>trochanter form an odd square shape when the bone is viewed
>laterally, and there is then a vaguely triangular hollow on the
>laterocaudal part of this 'lateral square' which has a raised
>ridge along its distal margin (this hollow and distal ridge are seen
>in both specimens). This ridge travels round to the caudal surface.

Based on your description, that sounds an awful lot like a posterior trochanter. Csiki and Grigorescu describe a "well-developed posterior trochanter" in Elopteryx, but their figures leave much to be desired. I can imagine seeing one there if I squint real real hard.


==================
John R. Hutchinson
Department of Integrative Biology Phone: (510) 643-2109
3060 Valley Life Sciences Bldg. Fax: (510) 642-1822
University of California
Berkeley, CA 94720-3140
http://www.ucmp.berkeley.edu/people/jrh/homepage.html