[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Re: ORNITHOMIMID THERIZINOSAURS



Peter Buchholz (there! got it right!) wrote:

<<I had previously spoken to Jaime privately about the posibility that
perhaps oviraptors and therizinosaurs were sister groups within the
Ornithomimosauria.>>

  He did. I forgot.

Jonathan Wagner wrote:

<As a quick aside, basal maniraptorform phylogeny is in such flux that
it is probably best represented by a trichotomy of Maniraptora,
Ornithomimisauria, Troodontidae, Tyrannosauridae, Therizinosauroidea,
and Oviraptorsauria (did I forget anybody?).>

  I will say that with a basal dentition like d-shaped unserrated
premaxillaries, at least several taxa form the base of the group with
a few out-flung branches (they're derived, in other words).

  *Pelecanimimus*, representing the ostrich-mimics
  *Sinornithoides*, representing the "troodonts"
  "Aublysodon" and *Shanshanosaurus*, representing the
     tyrants and allies
  *Compsognathus*, representing the "little fellows"
     (and you all know who you, all you dinos taken
      for granted when you could very well
      revolutionize dinosaur phyllogeny! Didn't Thomas
      Huxley say this?)
  *Ornitholestes*, arguably representing basal
      Maniraptora

  All others, which are dromaeosaurs and oviraptorosaurs, have either
speciallized premaxillary teeth or none at all, are advanced forms.
Each of the groups above that retained teeth but for the aublysodonts
and troodonts, respeciallized, either redeveloping serrations or
loosing the teeth. Among these, other features, included the pes,
shoulder, pelvis, and cranium, are to varying degrees supportive of a
general grouping of animals as provided in _Encyclopedia of
Dinosaurs_, a very parsimonious cladogram. Compsognathids are least
speciallized, and are basal to everyone else. Next comes tyrannosaurs,
mimics, and troodonts, sister (or parallel) to ornitholestids,
oviraptorosaurs, and dromaeosaurs + Avialae. Its a very nice one. See
below.

<<There are a lot of weird features of the basal ornithomimosaur that
suggest...>>

<*Which* basal ornithomimisaur?>

  *Garudamimus*, for one, largely because the dorsal orbital rim lies
below dorsal margin of the cranium, antorbital configurations
(fenestra and fossa), manibular bone sutures, and some other stuff
(don't have the full list, will be ammended soon. Among these,
*Harpymimus* also shows a few of the skull characters, the foot's a
little odd for an ornithomimosaur, the manual claws laterally
compressed (they're hooked, albeit not much) and the teeth are
similar, if not serrated, more bulbous (like troodonts') and smaller.

  It get's a little interesting, but the main problem is the foot. So,
a question: what's the best source for a full study of a foot of a
prosauropod (I've got _Complete Dinosaur_ and _the Dinosauria_ at
hand, but are there any better, or are these the best (not putting
down the work in there, of course)?

==
Jaime A. Headden

Qilong, the website, at:
http://members.tripod.com/~Qilong/qilong.html
---
All comments and criticisms are welcome!

_________________________________________________________
DO YOU YAHOO!?
Get your free @yahoo.com address at http://mail.yahoo.com