Re: BRONTOSAURUS, CHARLES DARWIN, AND MEXICO CITY

["Jerry D. Harris" <dinogami@hotmail.com>]

> Additionally, as Darren Naish has pointed out in one of the previous
> incarnations of this thread, people 30 and younger have always grown up 
> using
> the name Apatosaurus, and have always grown up with the story that
> Brontosaurus is not the right name (though, to be fair, many sources 
> confused
> this with the wrong head story).

  This should be appended to, perhaps, 20, or 25 at most.  I'm 30, but was 
unaware of the nomenclatural thing until in my teens.  As a child, I always 
called it _Brontosaurus_.

 >The only way to keep the genus Brontosaurus alive is do what Bakker >did 
and
> claim that the new species A yahnapin is the type of a new genus
> Eobrontosaurus and it is ancestoral to the genera Brontosaurus and
> Apatosaurus.  This is really pushing it and in opinion, making up names 
> >for
> the purpose of furthering an argument you know to be wrong.

  This would still require that he demonstrate why _Brontosaurus_ is a 
valid genus (and describe which specimens demonstrate this difference).  To 
my knowledge, this hasn't appeared in print...

> what Larsen is proposing is pretty much the same thing that
> happened to the genera Stenonychosaurus and Lesothosaurus: two pretty well
> founded genera that were sunk into older genera whos holotypes were 
> absolute
> crap (Troodon and Fabrosaurus  respectively).  Please refrain from doing 
> this
> in the future :-)

  Well, there is a long continuum of possibilities here.  A type specimen 
may be "crap" in the sense that only fragments are present -- say, for 
example, a single skull bone -- while another specimen may be very complete 
but lacking that skull bone.  If the skull bone of the first possesses an 
unusual and diagnostic feature or two, then basing a genus on it isn't a bad 
idea.  The second specimen can't be shown to belong to the first genus 
because it lacks the requisite comparative element; only a third specimen, 
possessing both the diagnostic skull element and comparable postcrania, can 
show that the first two are identical and that the latter should be sunk 
into the former.  This is a rather commonplace practice and I believe it is 
understood by anyone erecting a taxon that it's possible their taxon could 
be sunk.  In the absence of data demonstrating otherwise, I perceive that 
this is a useful practice that only rarely induces the kind of 
_Apatosaurus_/_Brontosaurus_ confusion.  The other option, really, is never 
to name _anything_ unless it is a complete skeleton, and just refer to all 
incomplete stuff by its collection number, because it can't be determined if 
it's identical to anything other incomplete material.  Even then, 
assumptions have to be made: if an isolated tibia is discovered and found to 
be identical to that in a complete skeleton with a name, we could assume 
that the tibia belongs to that genus, but it is also possible that it 
belongs to a wholly different genus which happens to have a very similar 
tibia.  Again, we do the best we can with the information at hand; future 
discoveries can and will always override past assessments.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Jerry D. Harris

AS OF JULY 1, 2000:

Dept of Earth & Environmental Science
University of Pennsylvania
240 S 33rd St
Philadelphia PA  19104-6316

Phone: (215) 898-5630
Fax: (215) 898-0964

E-mail: jdharris@sas.upenn.edu
and     dinogami@hotmail.com

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