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Re: Status of _Caudipteryx_



Larry Dunn wrote-

> Not to be cheeky, but what is the current thinking on
> _Caudipteryx_?  Is it seen as a feathered dinosaur or
> as a secondarily flightless bird?

Caudipteryx has only been included in a few phylogenetic analyses as of yet.
The whole secondarily flightless bird hypothesis is supported mainly by the
birds aren't dinosaurs crowd who like it because a feathered dinosaur would
ruin their phylogeny, although they have not ran phylogenetic analyses
themselves.  It was also supported by a hindlimb study whose flaws were
discussed at length on this list previously.  Originally thought of as a
non-avian avialan by Ji, Currie, Norell and Ji (1998), recently it has been
allied with oviraptorids.  Even Currie (1999 Ostrom Symposium) now places it
as an oviraptorosaur.  Sereno (1999) groups it as an oviraptorosaur basal to
caenagnathids and oviraptorids.  Holtz (1999 Ostrom Symposium) found it to
either be a basal maniraptoran or a basal member of the
segnosaur-oviraptorosaur group.  Although they did not perform a
phylogenetic analysis, Zhou and Wang (2000) came to a similar conclusion,
that it is either a basal oviraptorosaur or a basal paravian.  Xu, Wang and
Wu (1999) and Xu, Zhou and Wang (2000) (with near-identical analyses) also
find it to be a basal paravian.  Norell, Makovicky and Clark place
Caudipteryx in a troodontid + segnosaur + oviraptorosaur group that is
sister group to the Eumaniraptora.  My analysis always places it as a basal
oviraptorosaur, more primitive than Microvenator, caenagnathids and
oviraptorids.  Currently, Nomingia is its sister group, but I've based the
coding of Nomingia on the abstract and online photos only, so this may
change once I get the full paper.  So basically.....

Ji et al.                     (drom (Caudi + avians))
Sereno                     ((Caudi (caenag + ovir)) ((drom + troodo) +
avians))
Holtz(1)                   (Caudi ((segno (Micro + caenag + ovir)) (drom +
avians)))
Holtz(2)                   ((Caudi (segno (Micro + caenag + ovir))) (drom +
avians))
Zhou and Wang(1)   ((Caudi + ovir) (drom + avians))
Zhou and Wang(2)   (ovir (Caudi (drom + avians)))
Xu, Wang and Wu   (ovir (Caudi (troodo (drom + avians))))
Norell et al.              ((segno + Caudi + caenag + ovir + troodo) ("drom"
+ avians))
mine         ((segno ((Caudi + Noming) (Micro (caenag + ovir)))) (troodo
(drom + avians)))

* Troodontids are not shown in Holtz's phylogenies, as they had an equal
possibility of being non-maniraptorans or basal paravians.

I'd say the consensus is maniraptoran, but as my analysis includes the
characters used in the others (except Holtz', whose study in the Ostrom
Symposium has yet to be published, grumble...; and Norell et al., who
haven't published any kind of cladistic analysis yet, further grumbling....)
I feel it is most accurate.  Of course, there's a personal bias there :-)
but I think I can say with relative certainty that Caudipteryx is closer to
oviraptorosaurs than eumaniraptorans and that it is outside the
(Microvenator + Caenagnathidae + Oviraptoridae) group.

Mickey Mortimer