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Re: maniraptor taxonomy, etc.



In a message dated 7/19/00 10:00:58 PM EST, jeffmartz@earthlink.net writes:

<< Why?  What happens if when we find a primitive "mammal" or group of
 mammals that seems to have three sort of but not quite ear ossicles?  Are
 they "kind of" mammals?  How fully adapted do the bones have to be for
 hearing before it becomes a mammal?  What happens when you get a fossil form
 where the condition of the ear ossicles is debatable?  Did taxonomists using
 morphological defintions really agree any better about the membership of
 groups before phylogenetic taxonomists came along? >>

Allow me to point out that >precisely< this problem afflicts cladistic 
analysis and phylogenetic taxonomy: How should a particular character be 
scored? Is the length of the humerus 25% or 27% of the length of the femur? 
Measured which way? Is this lump really a trochanter or is it some neomorph? 
What exactly is "winglike" about this shape? How small must the fourth side 
be before a shape is triangular rather than tetragonal? Are there three ear 
ossicles here or are there not? What is "reduced"? What is "enlarged"? When 
does an "inflated" basisphenoid become an "inflated" parasphenoid? And so on 
and on. This is not an argument against using morphology merely to demarcate 
taxa, it is an argument against using morphology in cladistic analysis period.