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Re: Scansoriopteryx as Juvenile?



Jaime Headden wrote-

>   Well, the obvious thing is that its not. There are no neonate features
> of the animal, including an ossified scleral ring, distinct edges and
> margins to bones and processes of them, what appears to be well defined
> proximal tarsals and metatarsals, carpals, a coracoid with a well-defined
> acrocoracoid/biceps tubercle, and compared to *Epidendrosaurus*, a larger
> scapula with defined epiphyses, though surface distortions appear to be
> present; the vertebrae are also well ossified. *Scansoriopteryx* may be a
> sub-adult, but my own observation indicates that 1) it is not a neonate
> and 2) it is not even a juvenile.

I argued these points previously in Epidendrosaurus, and will do the same
for Scansoriopteryx-
1. Scipionyx has an ossified sclerotic ring, so these occured in very young
coelurosaurs.
2. Scipionyx also has "distinct edges and margins of bones and processes of
them".
3. Scipionyx has well defined carpals, while an embryonic Citipati specimen
has well defined metatarsals.
4. Scipionyx has a well-defined coracoid tubercle.
5. Scipionyx has well ossified vertebrae.
Scansoriopteryx may be an adult or subadult, but these features will not
show that.  What needs to be looked for are neurocentral sutures and bone
texture.

Mickey Mortimer