Re: Hanson 2006, Mortimer, Baeker response

["T. Michael Keesey" <keesey@gmail.com>]

On 6/24/06, David Marjanovic <david.marjanovic@gmx.at> wrote:
> From: "Mike Taylor" <mike@miketaylor.org.uk>
>
> > I'm not sure I can agree with your position.  For example, I've got
> > pretty bored of repeatedly writing "non-neosauropod sauropod"
> > recently; wouldn't it be nice just to define Eosauropoda as the
> > paraphyletic group (Sauropoda - Neosauropoda) and then just
> > refer to eosauropods?
>
> Then just do it: "For the purposes of this paper, we will define Eosauropoda
> as the paraphyletic group consisting of *Sauropoda* ([registration number])
> minus *Neosauropoda* ([registration number])..." "...we find that, instead
> of being a basal macronarian, *Haplocanthosaurus* is actually an
> eosauropod."

Isn't it so much simpler and clearer to just say, "We find that,
instead of being a basal macronarian, _Haplocanthosaurus_ is not a
neosauropod at all"?

Basically, your choice of where the "lower" bound for the paraphyletic
group is is arbitrary. You could say "non-neosauropod sauropod" here,
but you could also say "non-neosauropod eusauropod" or
"non-neosauropod sauropodomorph". Why? Because the novel information
is not that is a non-neosauropod whatever, but simply that it's not a
neosauropod. We already knew it was a sauropod (and a eusauropod, and
a sauropodomorph, etc...).

The formula "non-A B" is useful, but overused, I think.
--
Mike Keesey
The Dinosauricon: http://dino.lm.com
Parry & Carney: http://parryandcarney.com