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Re: Princeton Field Guide

On 1 October 2010 01:27, Anthony Docimo <keenir@hotmail.com> wrote:
>> >> > The book is a POPULAR work entirely in the style of a field guide for 
>> >> > birds
>> >> > or mammals. So it does not include specimen numbers, diagnoses or the 
>> >> > like
>> >> > and I don’t want to hear about it.
>> >>
>> >> Then how can it possibly be an appropriate venue to do wholesale
>> >> taxonomic reassignments?
>> >
>> > he said "popular" and "in the style of a field guide".
>> >
>> > if I'm reading _Amphibians of North Carolina_, it isn't to see which 
>> > supragenus the lungless salamanders are in this week.
>> Unless I'm misunderstanding you, that is pretty much the point I was making.
> Oh.
> here's what I thought you had said:  that it can't be an appropriate way to 
> do wholesale taxonomic reassignments _because_ it lacks numbers, diagnoses, 
> etc.
> ...so I pointed out the sentance which preceeded it.  (sometimes we skip a 
> line or sentance - its part of being human)
> ((want to be sure we're on the same page))

Oh, dear.  We are making heavy weather of this between us, aren't we?
I am pretty sure we're NOT on the same page.  Let me try once more.
Greg wrote a book "in the style of field-guide", which "does not
include specimen numbers, diagnoses or the like".  That's fine -- it's
an legitimate and popular kind of book.

HOWEVER, this book ALSO include wholesale taxonomic reassignments.  I
don't see how that can possibly be appropriate.  If you're going to
change an animal's name, then you need to do the work to justify that
change, which means engaging with "specimen numbers, diagnoses or the
like".  Otherwise we're left in the current situtation which is that
we know Greg thinks Aucasaurus garridoi should be Aberlisaurus
garridoi because ... well ... because Greg thinks so.  No-one can
either replicate or falsify his reasoning, because no-one knows what
it is.  I don't think that's at all helpful in sorting out the state
of dinosaur taxonomy.

>> >> > But dinopaleo has gotten into the bad habit
>> >> > of usually making almost every species into its own genus. This is 
>> >> > illogical
>> >> > considering that many modern bird and mammals contain large numbers of
>> >> > species – Varanus (now formally includes Megalania), Panthera, Felis, 
>> >> > Canis,
>> >> > Vulpes, Cervus, Tragelaphus, Cephalophus, Ovis, Gazella, Macropus, 
>> >> > Balaenoptera,
>> >> > Buteo, Falco, Anas.
>> >>
>> >> This is of course because dinosaurs are not modern birds or animals.
>> >> When taxa are known only from incomplete remains -- sufficient to
>> >> distinguish them from all other named taxa but not sufficient to yield
>> >> a robust phylogeny -- it's just more convenient to assign a name that
>> >> won't have to change when the phylogeny does.
>> >
>> > well, then I assume you will hold off from making any publications until 
>> > the phylogeny is changed for the last time?
>> No. But any new dinosaur taxa that I raise will be in new
>> monospecific genera unless I am really, really certain that I know
>> what they are most closely related to.
>  isn't that dangerously close to splitting?

Only if you think that putting a new taxon into a genus rather than a
species actually _means_ something.  But as Mickey has ably explained
in another message on this thread, it doesn't.  A name is just a
label.  And the one thing -- the only thing, really -- that you want
from a name is that it doesn't change.  The same name should always
refer to the same thing, otherwise it's useless.  And guess what?
Linnean binomials fail this basic test for the usefulness of names.
(At least, they do for fossil taxa.  I can see why they were a useful
idea for naming large groups of closely related extant critters.  But
for dinosaurs, they're a disaster.)

>> I wouldn't want to name a new
>> Diplodocus species D. docimoi and then find that it seems to be more
>> closely related to Barosaurus, and have to rename it B. docimoi.
>> Better just call it Novodiplos docimoi, and its name can stay the same
>> wherever it falls out in the phylogeny.
>  but if genera don't really exist, then wouldn't only the *docimoi* part 
> remain, when it falls out/into the phylogeny?

With extinct animals known from partial remains, a genus "really
exists" about as much as a species does, i.e. not at all.  It's just
about labelling in a useful way.

The bottom line is that we need to do two separate things: attach
unambiguous names to taxa (i.e. nomenclature), and figure out how
they're related to each other (i.e. phylogenetic analysis of one kind
or another).  Using a binomial conflates those two separate things.
It means that when we name a new animal, we are already committing to
a specific phylogenetic hypothesis.  And that is just plain dumb when
we all know how labile the dinosaur tree is.

> it would stop being *Novodiplos* rather like T.rex isn't called by its old 
> genus name (for want of a better example on my part), but the species would 
> remain the same.

No, the genus name would always have the exact same meaning.  You're
confusing this with the matter of priority.  It is true that the name
Apatosaurus is currently used instead of Brontosaurus, because it has
priority -- it was named earlier.  But the name Brontosaurus is still
there and still refers to the same thing, namely the Brontosaurus
excelsus holotype YPM 1980.