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Re: T. bataar (was RE: It's HERE!!!)



Thomas Holtz wrote-

> Actually, it's not me whose doing it: its someone else who used to post to
> this list... :-)

Ah, so there is unpublished information.  If I were smart, I would stop now,
but let's continue anyway.... :-)

> Other than ungual form, how do you get these as being "extremely
> dissimilar"?  More on _Anseri._ unguals below.

I did say "extremely dissimilar as far as ornithomimids go".  It's well
known that advanced ornithomimids are separated mainly on manual ungual form
and
skeletal proportions (although I think futher study would find many cranial
and postcranial differences as well).  Gallimimus seems a bit different, but
I don't know
how much of that is due to different interpretations by our Mongolian
colleagues, rather than real differences.  I was arguing that it would be
ridiculous to synonymize Anserimimus and Gallimimus specifically, not to
make all advanced ornithomimids congeneric (ala Paul 1988).  Within the
advanced ornithomimid group, Gallimimus is about the least similar form to
Anserimimus that you could get.  Non-ungual differences include the presence
of the following in Anserimimus-
1- coracoid tubercle located more posteriorly, ridge-like
2- widened, massive epipophyses of humerus
3- high, thickened deltopectoral crest
4- fused metacarpus
5- metacarpus compressed, no intermetacarpal space
6- metacarpal I longer compared to II
7- digit III shorter than I
8- elongate phalanx II-1 relative to II-2 (66% vs. 53%)
9- elongate phalanx III-1 relative to III-2 (48% vs. 111%)
10- ligament pits absent on phalanges III-1 and III-2
11- more advanced arctometatarsalian condition (mt's II and IV contact for
~40% of length)
There are three ungual-related characters as well.
Archaeornithomimus is closer in 5 (7, 8, 9 and 10 unknown).  Struthiomimus
also has character 1, nearly has 5 and is closer in 6 and 9.  Ornithomimus
has 5, 6 and 7 and is much closer in 9 (1 and 10 are unnown).
Dromiceiomimus and Garudimimus have very poorly preserved and/or described
forelimbs.  It's apparent that Anserimimus and Gallimimus are more
dissimilar to each other than Anserimimus is to other comparable advanced
ornithomimids, at least Struthiomimus and Ornithomimus.  Actually, I've
often thought of the widened humeral epipophyses, tall thick deltopectoral
crest, fused metacarpus without intermetacarpal space, elongate digit I,
enlarged flattened manual ungual I and advanced arctometatarsalian
metatarsus as being similar to mononykines.  Rather intriguing when Sereno's
and Martin's alvarezsaurid-ornithomimid hypothesis is taken into
account.....

> _Pel._ and _Deino._ I definitely buy; however, there is little described
in
> _Anserimimus_ so far that is distinctive from the _Gallimimus_-North
> American ornithomimid complex.  The manual unguals of _Anserimimus_ (its
> main diatgonstic feature) do not seem to be dramatically different from
> those of some of the North American forms (and I suspect that _Anseri._ is
> destined for junior synonymy, although not necessarily with _Gallimimus_).

Like I said, I wasn't agueing against the entire "Gallimimus-North American"
ornithomimid complex being congeneric, I was saying Anserimimus and
Gallimimus should not be synonymized exclusive of other ornithomimid genera.
Furthermore, unless there are some major errors in the text and figures, I
think Anserimimus is rather distinctive as far as ornithomimids go.  If it
were to be synonymized, I would expect it to be with Ornithomimus and
perhaps Struthiomimus, but unless you want to place Gallimimus in
Ornithomimus too, Anserimimus should be kept in a separate genus from
Gallimimus.

Mickey Mortimer