Re: New theropod phylogenetics paper

["T. Mike Keesey" <tmk@dinosauricon.com>]

On Mon, 4 Mar 2002, Fam Jansma wrote:

> Alright, a little sarcasm in between here, but why don't we all start to
> call everyone and everything on this planet "fïsh" or something like that.
> Fish are one of the first advanced back-boned animals and gave rise to
> amphibians who gave rise to reptiles and so fort.

"Fish" is a vernacular term, not a proper taxon. Even Pisces isn't used
anymore.

"Fish" in the strict sense corresponds to non-tetrapod craniates. (Same
could be said for "Pisces".)

Now, we do belong to Clade _Osteichthyes_, but that's another matter. (No,
it doesn't mean that we are "bony fish", any more than snakes being
tetrapods means that they are four-footed; a more proper vernacular term
for Clade _Osteichthyes_ would be "boned animals".)

> But to say that mammals are not reptiles is a bit rude, since they did
> evolve from one. I'm not advocating mammals _are_ reptiles, but they are
> descendants from the reptiles.

Depends on your usage of _Reptilia_. Phylogenetic taxonomists define it as
the last common ancestor of turtles (_Testudines_), lepidosaurs, and
crocodylians, plus all of that ancestor's descendants. Mammals are not
descended from any reptile under this usage. The so-called "mammal-like
reptiles" are just the non-mammalian members of another amniote lineage,
_Synapsida_.

--Amniota
  |--Synapsida
  |  `--Mammalia
  `--Sauropsida
     `--Reptilia
        |--Anapsida (=Parareptilia)
        |  `--Testudines
        `--Romeriida (=Eureptilia)
           `--Sauria
              |--Lepidosauromorpha
              |  `--Lepidosauria (incl. Squamata & Sphenodon)
              `--Archosauromorpha
                 `--Archosauria (=Avesuchia)
                    |--Crocodylotarsi (=Pseudosuchia)
                    |  `--Crocodylia
                    `--Avemetatarsalia (=Ornithotarsi, Ornithosuchia, Panaves)
                       `--Neornithes (=Aves sensu Gauthier)

> And another example, birds are reptiles! See what the list comes up with
> this one... :)

Cladistically, they are. (see above)

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