[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Re: Greg Paul is right (again); or "Archie's not a birdy" + paper requests

> That's _Euornithes_. Do you really think this is the clade
> that most
> deserves the name _Aves_? I mean, the known composition of
> the clade
> in question is equivalent to something like
> (_Archaeorhynchus_ +
> _Neornithes_). What is so important about it? What
> significant
> apomorphies do we currently believe originated there?

1. crown group-type tail
2. crown-group-type growth to maturity

The euornithean lineages that didn't make it past the Mesozoic were restricted 
in distribution and/or diversity. Their extinction is unsurprising. The 
presumed/supposed sister group was massively diverse, had a global 
distribution, and still *didn'*t make it.

That's quite important, I'd guess. If there was something other than chance 
that caused some theropods to survive, its origin is most likely in Euornithes. 
That is so irrespective of whether Ornithothoraces are a clade or an artefact - 
if they are not a clade, Enantiornithes are still "very close" to Euornithes, 
they are simply not necessarily "closer than" some other avialans anymore. 
Avialae is Avialae, no matter whether it's grassy or combed halfway up.

(I don't think that the question of the basal avialan relationships can be 
answered properly until we have identified good candidates for the long-tailed 
ancestry of all "pygostylians". Hence the need to reanalyze the long-tailed 
guys together with _Xiaotingia_ and basal members of the 4 avialan lineages. 
Particularly _Jixiangornis_ - did they include it in the _Xiaotingia_ paper? 
Avialan or not? Likewise, _Yandangornis_ seems to have been all but forgotten, 
but it certainly looks quite interesting these days. Has it *ever* been 
quantitatively analyzed?

The Cretaceous long-tails cannot be ancestors, they are too young. But they may 
represent persisting relatives of the long-tailed ancestors of short-tailed 
birds. They might wreck the hypothesis of the _Xiaotingia_ description.

Trying to get as close as possible to the toothed ancestor of _Confuciusornis_, 
and to the long-tailed ancestor of _Passer_ and _Enantiornis_, that is the 
challenge now.)

Does anyone have a copy of the _Xiaotingia_ and _Shenshiornis_ descriptions 
BTW? I just realized I was so tied up with glacial-era speciation in the Amazon 
that I actually never grabbed the latter.

Thanks in advance,