Re: Longisquama closer to theropods than sauropods?

[Dinogeorge@aol.com]

In a message dated 8/17/99 9:59:58 AM EST, mbonnan@hotmail.com writes:

<< Well, actually Hatcher reported what might be furculae for Diplodocus in 
his 
 1901 monograph on the Carnegie specimen (Hatcher, 1901. Diplodocus (Marsh): 
 it's osteology, taxonomy, and probable habits, with a restoration of the 
 skeleton. Memoirs of the Carnegie Museum, Vol1. No1. Pg.41 w/Illustration).  
>>

I recall these turn out to be clavicles or some such, but my references are 
currently buried and I can't get at them. Jack McIntosh in The Dinosauria 
does not note furculae for Diplodocus in his paragraph on the shoulder girdle.

<< In any case, since sauropods are saurischians and share a number of 
 anatomical features with theropods, why do you think _Longisquama_ would be 
 closer to theropods and birds than sauropods?>>

For me, Saurischia doesn't exist--or rather, it is a synonym of Dinosauria 
itself. The characters purportedly uniting sauropods and theropods are either 
plesiomorphies (e.g., saurischian pelvis, skeletal pneumatization), 
convergences (e.g., hyposphene-hypantrum articulations of the vertebrae), 
poorly defined, or just plain incorrect. I reviewed the characters listed in 
The Dinosauria long ago and may even have sent my views to this list. I see 
sauropodomorphs and ornithischians as more closely related to each other than 
either group is to theropods. This is also the view of Charig, Cooper, and 
Bakker (all independent of one another).

<<  Would you stick _Longisquama_  as a sister group to theropods and birds, 
and if so, where would the Sauropodamorpha go?>>

See above.

<<  Something different?  Is _Longisquama_ a saurischian,  then, by your 
definition? >>

Since Saurischia = Dinosauria, _Longisquama_ would be a saurischian.

Who knows? I may be wrong about _Longisquama_, but this has nothing to do 
with the cladistics of sauropodomorphs, theropods, and ornithischians.