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

Re: Caenagnathus species (mercifully short :-) )

Jaime Headden wrote:

>  I think this method is good, but in its own way, not
>as a genus/species identifier/diagnoser, but as Raath
>(1990) and Colbert (1990) suggested for their
>respective genera (*Syntarsus* and *Coelophysis*), as
>sexual dimoprhic indicators. Relative robusticity of
>*E. rarus* to *E. elegans,* or *C. pergracilis* to *C.
>sternbergi* (= *C. elegans*?) is based on very little
>evidence, and as both authors showed, partially
>seconded by Carpenter (1990), the femur and pelvis are
>the most distinctive probably indicators of sexual
>dimorphism. Only *C. pergracilis* preserves the
>relavant material, as recognized.

If we subdivide the North American material on the basis of _Chirostenotes_ 
vs _Elmisaurus_ diagnoses AND robust vs slender, we get.:

                Chirostenotes              Elmisaurus        

robust        NMC 8538, NMC 9570               -           
                  NMC 2367

slender         RTMP 79.20.1               ROM 781               

condition                                ROM 37163 (juv.),           
not given/        ROM 43250               RTMP 82,39.4             

This is just the described postcranial material (i.e. excluding 
_Caenagnathus_ jaw-bones).

NMC 2367 is the holotype of Chirostenotes pergracilis
NMC 8538 is the holotype of Macrophalangia canadensis
ROM 781 is the holotype of Ornithomimus elegans
RTMP 79.20.1 is the specimen that showed Macrophalangia was the same as 
ROM 43250 is the "new" specimen described by Sues (1997) that shows 
Caenagnathus to be the same as Chirostenotes; it includes cranial material, 
but unfortunately no metatarsus.
The other specimens are isolated pedal elements.