Re: Defining crocodiles as "fish"... :-)

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

On 8/21/06, Nick Pharris <npharris@umich.edu> wrote:
> Though, according to phylogenetic taxonomic principles, if lampreys,
> sharks, salmon, and coelacanths are all "fish", then crocodiles are,
> too (along with aardvarks, salamanders, hummingbirds, etc....)!

Well, no, because "fish" is a vernacular term, and that clade is
already called _Craniata_ (and may be synonymous with _Vertebrata_).
Similarly, we are not usually considered apes or monkeys, but we are
definitely hominoids and simians.

> On another topic, the article you quote gives the following definition
> of "fish":
>
> "completely aquatic vertebrates, having gills, commonly fins, and
> typically an elongated body usually covered with scales."
>
> "Commonly" fins?  Are there any species of fish that completely lack them?

Hagfish, no?

I think "non-tetrapod craniate" is a good technical equivalent of
"fish" (at least as the term is commonly used in biology--popular
usage is often more inclusive).
--
T. Michael Keesey
The Dinosauricon: http://dino.lm.com
Parry & Carney: http://parryandcarney.com