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Re: Benton et al.'s Supertree & The ecology of the Cloverly forma tion



I reiterate my dislike for supertrees.  They are inherently flawed by the
inclusion of multiple cladograms that use much of the same data.  In fact,
Benton et al. used several cladograms specifically based on previously
published data, with an extra taxon added (eg. Charig and Milner's 1997
cladogram which was basically Holtz's 1994 analysis with Baryonyx added).
This particular supertree also used cladograms that weren't even based on a
phylogenetic analysis (such as all those in The Dinosauria).  Supertrees
constructed this way are not even accurate consensuses of current opinion,
as both recent and outdated trees are used (eg. Holtz 1994 and Holtz 2000).
They certainly can't give us new information as to phylogenetic
relationships.

Tim Williams wrote-

> _Lesothosaurus_, _Gongbusaurus_, and _Agilisaurus_ form a monophyletic
> group, one node higher than _Pisanosaurus_ at the very base of the
> Ornithischia. (I think the name Lesothosauridae is available for this
> clade).

The particular placement of Gongbusaurus and Agilisaurus in the
Fabrosauridae was probably based on Peng's 1997 chapter in the Encyclopedia
of Dinosaurs.  I don't have that reference, but his reasoning for the same
arrangement in 1992 was less than convincing (again, not based on a
phylogenetic analysis).

Many other conclusions of this supertree have similar problems.

Mickey Mortimer