Re: A Clutter of Duckbills

[Robert.J.Meyerson@uwrf.edu (Rob Meyerson)]

>Just what keeps two species in the same genus?  And just what keeps them
>separate?

Often little more than the opinion of the researcher.  Usually, when two=
 groups of animals are given species names, they are placed in a genus where=
 the similarities of that group more or less match that of previously=
 documented species.  The problem is that there is no set criteria to define=
 what "more or less match" means.  Granted, we can look at modern animals,=
 compare the diversity shown in their populations, and try to apply that to=
 a fossil species, but this will inevitably lead to a wrong conclusion=
 somewhere, because we rarely will know what diversity existed within the=
 species in question.  The only way to bypass this problem is with more=
 finds, and more specimens.  Ultimately, as more and more fossils are=
 discovered, we will be able to work out many of these questions (another=
 point for those who want to limit private collecting).

Rob

***
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