*Beipiaosaurus* Recapitulated

["Jaime A. Headden" <qilongia@yahoo.com>]

To all:

  To reply to Dinogeorge's assessment of
*Beipiaosaurus* -- and offer my own observations, as I
have now, after long waiting, been able to aquire the
references (though not some I would like).

  I'm gonna ignore the skull for now. Xu et al. (1999)
say that the ilium was similar in shape to that of
dromaeosaurs and basal birds (that is,
parellelogrammic) but the dorsal border is missing, so
I doubt this much; given features similar to both
therizinosauroids and oviraptorosaurs, it would
probably be arched to some degree over the acetabulum.

  The pes is very short, longer than a fourth the
tibial length, but shorter than a third, and the
proximal end of mtiii is broad, not compressed in ovis
or therizinos. The astragalus is narrowed, as in
therizinosaurs, exposing some of the distal tibial
surface, but has a tall ascending process. It does not
appear to be ornithomimosaurian or oviraptorosaurian
in derivation, but neither does it appear to be
"prosauropodan," too. Tibia and femur close in length,
as in *Alxasaurus.*

  A furcula pretty much dismisses the prosauropodan
aspect of its biology as a "fluke;" as in
caenagnathids and therizinosauroids, mci is only half
the length of mcii, rather than a third or shorter as
in other maniraptorans. The hands are typical
maniraptoran, though, and the claws are very strongly
recurved, nasty wicked things that would probably be
analogous to thagomizers.

  The skull? The teeth have constricted bases, and
unlike the Lufeng jaw (I got that ref, too), they look
like *Alxasaurus* and troodont teeth. The lateral
crest on the dentary ... What else can I say? It looks
like a basal therizinosauroid --- with dinofuzz. Oh,
Therizinosauroidea, given the duplicity of characters
in the foot and manus, it would most parsimoniously
form a trichotomy with ornithomimosaurs and
oviraptorosaurs+paravians. Oh well, others have
suggested that one years ago, most recent in my
recollection would be Peter Buchholz, right here.

  Still, you never know....

===
Jaime A. Headden

"May I lure us, ere the mote ends us?"

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