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Re: Avian origins: new analysis confirms ancient beginnings



> Whoops, my bad. At least six lineages. (Any other
> stem-anseriforms
> we're forgetting?)

2 candidates I know of - one has an upcoming paper by
(IIRC) a DML member and I won't spoil the surprise,
the other I have not looked at in detail - at least 1
supposed phorusrhacid *might* qualify. (Giant terror
ducks of doom... AGAIN? Aha?...[*])

> Yes, I would imagine the actual number is probably
> quite a bit higher
> than six, probably including several neoavian
> lineages. But who knows?

Mickey's draft theropod tree manages to resolve
perhaps 80% of the putative neornithine fragments from
the Mesozoic reasonably well to the usual suspects;
very little of the material turns up where no
qualitative analysis has proposed it to belong. Which
is no mean feat - not due to the qualitative analyses
as there have been many for most of these fragments,
but in the scope of the cladistic analysis: adding a
quite nondescript humerus piece like _Torotix_ will
certainly not make the overall tree more robust.

> (I think "ciconiiform-pelecaniform clade" or
> "ciconiiform-pelecaniform
> crown group" is sufficient.)

In any case, some of those below (and then some)
appear more pelecanimorph/sulimorph/... than
procellarimorph/gaviimorph/... at least qualitatively.

> > We have a few bones of
> > what seem proto-procellariiforms out there around
> the
> > boundary, but at present nobody tried to check out
> > whether they're not simply very plesiomorphic
> basal
> > members of the tubenose-et-al clade.
> 
> Interesting.

An overview might actually be easy. Most material is
reviewed in Hope's 2002 quantitative analysis. If one
straps Livezey/Zusi's character state data onto the de
facto consensus tree of the group (which at least for
the tubenoses is very well resolved by now), it should
be possible to do a quick-and-dirty
plesiomorph/apomorph assessment of the fragments'
features.

Candidate taxa: _Lonchodytes estesi_,
_Novacaesareala_, _Torotix_, _Tytthostonyx_. Also
_"Lonchodytes" pterygius_ and _Telmatornis_ which
almost certainly aren't proto-Procellariiformes, to
find out just how far apart these are from that group.
Some unnamed material also exists (Turgai Sea shores
and adjacent Mongolia mainly).

And of course... those wicked guys, _Neogaeornis_ and
_Polarornis_. For both, the tubenoses-et-al provide a
place that fits well in space, time, and is by and
large compatible with the material. Mickeys tree finds
them Gaviiformes, which would be stem-, i.e. somewhere
basal to Gaviidae. Reasonable, but IIRC N. is known
from remains less diagnostic than one would probably
want. P. might use codings ultimately based on
Chatterjee, and man did he WANT this to be a modern
loon... (as one would probably need it to be if one
started avian evolution in the Triassic...)
;-)


Regards,

Eike


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