Message 2001-06-0128: Re: Crown groups mainstream?

Sun, 24 Jun 2001 11:42:31 +0200

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Date: Sun, 24 Jun 2001 11:42:31 +0200
From: David Marjanovic <>
To: PhyloCode mailing list <>
Subject: Re: Crown groups mainstream?

>      To say that a crown group Mammalia is "mainstream" is perhaps a bit
> Ivory Tower tunnel-vision and/or wishful thinking.  Just because McKenna
> Bell recognize such a crown group doesn't mean it is "mainstream" or
likely to
> become so.

I was talking about paleontologists -- there it seems to have become
mainstream, means, it is used in nearly all papers on mesozoic mammals I
know (which aren't too many).

>       Most mammalogists still seem to think that a Mammalia which is
> cladistically anchored on a monotreme (which still have a miserable fossil
> record) is a dumb idea.
> [...]
>       I would very HIGHLY recommend that PhyloCode workers NOT define
> as a crown group, because there is a good chance it will end up excluding
> multituberculates, and it will certainly exclude sinoconodonts,
> morganucodonts, and docodonts (all of which have the well-known mammalian
> and three ear ossicles).

As far as I know, docodonts may even be inside (I don't know what has become
of them); however, all post-Early Jurassic mammals are currently inside,
including triconodonts and multituberculates. The position of monotremes has
been cleared up in January -- they belong to a larger group called
Australosphenida, along with several previously enigmatic Mesozoic mammals
(I posted); the sister group of this is the previously also enigmatic
*Shuotherium* from China, and the next outgroup is the clade that contains
all other post-Early Jurassic mammals. So the difference in content is
small -- and Mammaliaformes is there to recieve Mammalia and the three early
groups you mentioned.
        Actually, I'm not defending crown-group Mammalia (it's rather
unimportant to me, I'm mainly interested in dinosaurs :-) ), I just want to
explain that this proposal is by far not that ludicrous.

>       I think it is pretty obvious a crown group Aves has been rejected
> already, and who knows what might happen to a crown group Archosauria,
> pterosaurs may not be the only group that gets ejected from that taxon.

What else would you move out of Archosauria? ~:-|


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