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Re: Recoded Aves introduces a lot of fog?



----- Original Message -----
From: "Mickey_Mortimer11" <Mickey_Mortimer11@email.msn.com>
Sent: Wednesday, February 13, 2002 4:52 AM


> > Very strange places for both *Yandangornis* and *Sapeornis*. The latter
is
> > almost obviously the sister group of Pygostylia.
>
> The precise relationships of Yandangornis, Sapeornis and
confuciusornithids
> are quite uncertain at this point.  As I wrote previously-
> Yandangornis is more derived than Sapeornis based on-
> fibula does not reach calcaneum;

cursorial adaptation

> [....] reduced manual unguals.

Overlooked that.

> It's less derived than Sapeornis based on- cervical centra
> not heterocoelous; absence of pygostyle?.

_Long tail_. And I'd need good evidence to accept a reversal of that, given
the fact that all other known cursorial birds have never reevolved a sizable
tail, even though they could use it.

> Also, there are a couple
> characters in [...] Sapeornis (ulna longer than humerus; scapular
> shaft tapering distally) that are more derived than confuciusornithids.

Convergent adaptations to flight, I'd say. To me *Sapeornis* is what comes
out when a bird slightly more basal than *Confuciusornis* becomes a better
flier, maybe with a gull-like ecology, than the latter.

> Remember, resemblence of Sinornithoides' metatarsus is caudal view to that
> of pygostylians' in cranial view is no more meaningful than if one taxon's
> pubis resembled another's scapula. :-)

Sure. Just I assume that pygostylian metatarsi look similar on both sides;
the few that I've seen so far do. I'm not advocating such a phylogenetic
position for troodontids :-)

Just had a look at
http://www.fieldmuseum.org/museum_info/press/press_sinovenator.htm... says
Zhang Miman is a woman. Thus the name *Sinovenator chang_ii_* must already
be emended, no?

Too bad the illustration isn't good enough to show how many exits for nerve
V the braincase has, and the text doesn't mention it :.-(