Re: Amniota ( was re: synapsids are reptiles )

["T. Michael Keesey" <mightyodinn@yahoo.com>]

--- Jean-michel BENOIT <Jean-Michel.BENOIT@gemplus.com> wrote:
> You mean there's no taxon assigned to Amniota alone (apart from Syna_ and
> Sauropsida)?

There is exactly one -- the ancestral amniote.

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

Amniota = Clade(Mammalia + Reptilia)
Sauropsida = Clade(Reptilia <-- Mammalia)
Synapsida = Clade(Mammalia <-- Reptilia)

If _Diadectomorpha_ does belong to _Amniota_, by virtue of being decended from 
the last common
ancestor of _Reptilia_ and _Mammalia_, then it depends on whether it shares 
mroe recent ancestry
with _Mammalia_ or with _Reptilia_. (If the former, they are synapsids, if the 
latter, they are
sauropsids.)

Currently I think the general consensus is that they are close to amniotes, but 
not within _Amniota_.

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=====> T. Michael Keesey <keesey@bigfoot.com>
=====> The Dinosauricon <http://dinosauricon.com>
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