Re: Life of Birds (vertical running)

["David Marjanovic" <david.marjanovic@gmx.at>]

> Continue this for long enough, and you reach the
_Archaeopteryx_-_Rahonavis_
> stage of bird evolution.
>
> Tim

What is this stage in your opinion? There are too many interpretations of
*Archaeopteryx* around for me to remember... :-]

*Rahonavis* seems to have been the better secretary bird. According to a
claw study (an SVP meeting abstract from 1998 I cited in June or July) it
was terrestrial (the claws are straighter than in *Archaeopteryx*), and it
was a better flier, according to its quill knobs and the fact that (despite
the rather long legs!) the ulna is the longest bone in the skeleton, unlike
normal theropods including *Archaeopteryx* and even *Confuciusornis*, where
that is the tibia. Fascinating convergence.
        So whatever the *Archaeopteryx* stage is, it can hardly have been
the same as the *Rahonavis* stage IMHO.