Re: Amniota ( was re: synapsids are reptiles )

["David Marjanovic" <david.marjanovic@gmx.at>]

----- Original Message -----
From: "Jean-michel BENOIT" <Jean-Michel.BENOIT@gemplus.com>
Sent: Monday, April 15, 2002 1:16 PM

> You mean there's no taxon assigned to Amniota alone (apart from Syna_ and
> Sauropsida)?

Yes, by definition. Except the very first amniote (species? pair?
population?) which is of course unknown.

> What about Diadectomorphs?

Currently thought to be outside:

Crown-group Tetrapoda
  |--Amphibia (stem-based clade)
  `--+--*Solenodonsaurus*
     `--+--Diadectomorpha
        `--Amniota
              |--Theropsida = Synapsida
              `--Sauropsida

Of course that says nothing about whether they laid amniotic eggs, and vice
versa.

> If it turns out they're Amniotes, are they Sauropsids or Synapsids?

That will certainly turn out should they ever be found to be amniotes. Can't
say that a priori. (There has been an analysis that found them at the base
of Theropsida; this has been refuted, though.)