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RE: Shenshiornis (was Re: The Karate New Papers)



> In general, I am skeptical of the claims that sapeornithids
> were strong fliers.  I'm not convinced they were
> capable of powered flight at all.  No known
> sapeornithid has the sternum preserved:  both
> _Sapeornis_ species, _Didactylornis_, _Shenshiornis_,
> _Omnivoropteryx_ (assuming it's a sapeornithid).  The
> sternum was undoubtedly present, but likely not ossified in
> life.
> 
> 
> The claims that sapeornithids had "powerful flight
> capabilities" seem to be based mostly on the highly
> elongated forelimbs.  OK, so they had a pygostyle too;
> but there's no evidence that the pygostyle started out as a
> flight-related character.

The scapular angle at least of _S. chaojangensis_ was also extreme according to 
Senter's APP study, well within the range found in nonavians. All things 
considered, they seem to have been fairly expert (for their time) soarers, with 
a tree-down launch mode.

Though IIRC not enough sapeornithid plumage has been discovered yet to say much 
about their wing shape. But I *think* the ratio of primary:secondary remiges 
length was not as extreme as in _Confuciusornis_. If that is so, the flight 
capabilities of these two were probably more similar to each other's, than 
either's was to that of e.g. _Gansus_ or _Eoalulavis_, while differing in 
details. That there was *some* difference is almost certain, considering 
sapeornithids lacked the humeral apomorphies that allowed confuciusornithids a 
powerful downstroke, even if they still had no significant upstroke. 
Sapeornithids may have had neither.


Regards,

Eike