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RE: What, if anything, is _Apatosaurus_ (Was: Ceratops (was RE: Pterosaur diversity (was: Re: Waimanu)))

Mike Taylor wrote-

The moment you
see one of those honking great cervical ribs, you know what you're
dealing with instantly.  So how can it be that in a cladistic
analysis, such an obviously distinctive character counts for no more
than, say, an unobtrustive rugosity on the lateral face of the distal
part of pedal phalange II-2?  That's just wrong.

Well, these apomorphies weren't decided by a cladistic analysis, but I agree weighting is a tricky issue.

 > Using Wilson and Upchurch's criteria, very few sauropod genera
 > would be valid.

Really?  What are the criteria that you allude to exactly?  That each
valid genus should be diagnosed by at least one autapomorphy?  I would
think that most sauropod genera have that.

Nick Pharris answered this well.

 >> 3. If we consider names ending -idae (etc.) to be "family-level"
 >> and therefore governed by the ICZN, then Wilson and Upchurch
 >> (2003) are right that Titanosauridae must also die;
 > Er, why?

Because (early in the argument) I posited that _Titanosaurus_ is
rightly considered a domen dubium.  If you contest that assumption,
the rest of the argument doesn't follow.

But I noted that the ICZN says NOTHING about nomina dubia. A taxon should merely be "well known" if it has a family-level group named after it. Titanosaurus is well known, wouldn't you say? Which dinosaur worker hasn't heard of it? I really don't know why Wilson and Upchurch (2003) started the whole 'family-level taxa can't be based on nomina dubia' myth. Find the part of the ICZN that says that. I don't think it exists.

Mickey Mortimer