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RE: New Cretaceous bird and other papers



> > Doesn't it feel like you're really *trying* to stretch things out?
>
> I'm definitely arguing on little evidence.

Won't argue with that one.

> > Why is it then
> > so hard to accept the existence of Falconidae or Accipitridae
> less than 10
> > million years before we find their fossils, especially when molecular
> > evidence says they should have been there?
>
> Because molecular clocks so frequently contradict known fossils,
> and because
> their error margins are impressive. I mean, 65 -- 83 Ma. Take the
> lower end
> and you almost reach the earliest fossils; take the upper end and
> Falconiformes is older than *Apsaravis*.

Dunno why *Apsaravis* has to be the earliest member of its lineage...
hesperornithiforms are present in the Early Cretaceous, and presumably
earlier. We still have coelacanths, which are pretty similar to the ones we
find in the Paleozoic. Also lungfish.

The error margin is troubling, but I note that the entire thing is still in
the Cretaceous.

> >[my parrot rant].
>
> It has diagnostic characters of _crown group_ parrots and
> _lorisiids_. It's a bit too good to be true.

Pretty scientific statement there.

> > And it's right where the molecular analyses say it
> > should be, just like our phylogenetic analyses say there should be
> troodonts
> > in the Middle Jurassic.
>
> Molecular clock estimates are a different thing than molecular
> phylogenies. You compare the former with morphological phylogenies... hm.

No... I said "molecular analyses" and "phylogenetic analyses". I probably
should have said "morphological" for the latter, that's what I meant.
Neither molecular nor morphological phylogenies tell you *when* your clades
arise. To align your cladogram with a timescale you need molecular clock
data and the fossil record (including ghost lineages), respectively. All of
this is included when I say "analysis". If that wasn't clear, it was my
fault. I'm sure there is a better word for it.

>         Speaking of phylogeny, parrots are nested _high_ in Neornithes.
> Having a lorisiid in the LK drags the other two clades of crown group
> parrots, the Eocene parrots, and at least Columbiformes with it -- that's
> quite an impressive diversity!

That's sort of my point here. Case in point -- we have *Polarornis*, an
unquestionable loon, in the Maastrichtian. That alone drags the common
ancestor of Charadriomorphae (which I believe includes parrots and pigeons)
into the Mesozoic with it. And Gaviiformes are nested *high* in the
Charadriomorphae. This, as I read the cladogram, means that
Phoenicopteriformes, Ciconiiformes, Pelecaniformes, Procellariformes, and
Sphenisciformes were also present in the Cretaceous. Will we find a
Cretaceous flamingo?

The whole above statement assumes that the Charadriomorphae is a real group,
of course (in bird systematics, take nothing for granted).

>But assuming almost the entire diversity of Neornithes in
> the Cretaceous is IMHO a stretch.

Is there any *positive* evidence for your HO, or does it just rely on the
current pitiful sampling of the Cretaceous avian fossil record? More and
more neornithean diversity is found in the Cretaceous every year. When does
it stop being a stretch?

Mike D.