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Re: wow! another application form! :-)



In a message dated 12/2/98 7:12:32 PM Eastern Standard Time,
Dwight.Stewart@VLSI.com writes:

<< SO, I second George's question: what's a reptile?  UH, aside from my
 boss, of course. :-) >>

While I appreciate a definition based on a 'crawling, scaly' mode of life,
another possible definition is:

The other great clade of amniotes is Reptilia (reptere - to creep).   Reptilia
refers to  Anapsida [turtles] and Diapsida, and to all the forms down to their
most recent common ancestor...From the modern world we know these animals best
as turtles, snakes, lizards, crocodiles, the tuatara, and birds, and from the
past, as dinosaurs and their close relatives, the pterosaurs...Reptilia is
diagnosed by a braincase and skull roof that are uniquely constructed and by
unique features of the neck vertebrae...
Diapsida (di - two; apsid - arch) is united by a suite of shared, derived
features, including having two temporal openings in the skull roof, an upper
(or supra) and a lower (or infra) temporal fenestra...
Finally, we come to the other [besides Lepidosauromorpha, which include snakes
and lizards] great clade of diapsids, Archosauromorpha (archo - ruling; sauros
- lizard; morpha - shape).  Of particular interest to us, however, is the
famous clade within the archosauromorphs, Archosauria...among whom are
included crocodiles, dinosaurs, pterosaurs, and birds [sic for those who
disagree]...
The last of the aforementioned [basal members] - prolacertiforms - possess a
number of significant evolutionary innovations..., most notably an opening on
the side of the snout, just ahead of the eye, called the antorbital
fenestra...

To hurry the story along, Archosauria includes a clade called Crurotarsi
(crocodiles) and our subject Ornithodira.  Quoting again,
Ornithodirans are united by the fact that within the archosaurs, they alone
possess an erect, or parasagittal, posture...
(The Evolution and Extinction of the Dinosaurs, Fastovsky and Weishampel, pp
86-88)

Though why distinctions should be based on holes in the skull rather than,
say, treatment of employees is a puzzlement.