From: "David Marjanovic" <david.marjanovic@gmx.at>
Reply-To: david.marjanovic@gmx.at
To: "DML" <dinosaur@usc.edu>
Subject: Re: How are columbiformes (doves and pigeons) related to
psittaciformes?
Date: Mon, 10 May 2004 21:41:14 +0200
> What ARE Mayr's objections to this specimen? I am HOPING this isn't
> based solely on the stratigraphic location....
The stratigraphic location, and the several synapomorphies that the jaw
shares with _lorisids_, with a _part_ of the _crown group_ of
Psittaciformes. The oldest known parrot-beaked parrots (still not lorisids,
AFAIK) are Oligocene, none are known from the rich deposits of the Eocene
or
earlier. There are several bird clades from that time and place for which
we
don't know skull material, plus we don't know when e. g. confuciusornithids
really died out, and in addition there are definitely unknown Cretaceous
bird clades waiting to be discovered, so assigning that isolated lower jaw
to a part of the crown-group just because it shares a few characters with
that clade seems premature to them... and me.
> Supposed
> caenagnathid synapomorphies are found in crown parrots as well, and this
> does not absolve the avian features of the jaw that caenagnathids lack
but
> the Lance jaw possesses.
Mayr et al. don't say it's a caenagnathid.