Message 2003-12-0008: Re: One more Recommendation?

Fri, 05 Dec 2003 23:07:08 +0100

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Date: Fri, 05 Dec 2003 23:07:08 +0100
From: David Marjanovic <>
To: PML <>
Subject: Re: One more Recommendation?

> I disagree with this idea.  To take the
> example of Eupelycosauria, I think that we might
> want to define that name because there is
> currently no synonym.  Pelycosauria was never
> defined and presumably never will be because it
> would  refer to the same clade as Synapsida.

I agree so far...

> Synapsida was preferred (over Pelycosauria)
> presumbaly because of the symmetry with
> Sauropsida (Synapsida and Sauropsida the two main
> clades of amniotes) and because it is less
> incomplete than Pelycosauria.  This is because
> Synapsida included both Pelycosauria and
> Therapsida.

Regarding the symmetry... Theropsida, which has already been used this way
( = sistergroup of Sauropsida), would have been still preferable over
Synapsida. :-) But if Synapsida were given an apomorphy-based definition (as
one could argue its name suggests), its known contents would be identical.

> So, we probably should never define
> Pelycosauria, but that does not mean to me that
> we should not define Eupelycosauria.  This way,
> we could retain some old names that could be
> useful to maintain some taxonomic continuity,

Hm. See Pelycosauria above -- the continuity of content would be quite

> provided that part of the meaning of the name is
> preserved under PN (in this case, much of the
> meaning would remain).

Pelycosauria, and by implication Eupelycosauria, has always been assumed to
explicitely exclude therapsids & mammals. I think we really should come up
with a new name -- there will be less confusion than if we'd suddenly find
ourselves being eupelycosaurs. (With the added strangeness of nothing being
a pelycosaur.)


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