fossils as roots

[Curtis Clark]

At 07:38 AM 3/3/99 -0700, Hilary Davis wrote:
>I'd like to hear some opinions on the use of fossils to root a cladogram
>or tree.  Is this a valid technique given the possibility that a fossil
>assemblage for a particular extant group may not be complete?

Do you mean use a fossil as an outgroup? It should work as well as any
extant species: if it weren't extinct (a "living fossil"), and you'd have
no hesitation in using it then, its extinctness shouldn't be an issue. The
only question would be whether it has states for all the characters used in
the analysis of the living species.


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