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Re: Dinosaur Books and Movies



On Thu, 22 Mar 2001 Buckaroobwana@aol.com wrote:

> Does this mean that every Daffy Duck cartoon ever made also qualifies as a
> dinosaur flick?

Yep. (There is a prehistoric one, too, with an idiotic sauropod and a
caveman Will Rogers(?), IIRC.)

> Seriously though, what anatomical features qualify a candidate for bird
> status? Where do dinosaurs end and birds begin?

Dinosaurs do not end where birds begin, since birds are dinosaurs.

> I remember GSP pointing out that there are no great anatomical
> differences, but what minor ones exist to define Aves?

There are surprisingly few. Most of the features we use to distinguish
modern birds (_Neornithes_) from other extant animals are synapomorphies
of clades other than _Aves_, either more inclusive (feathery integument,
three manual and four pedal digits, pneumatic skeleton, etc., unserrated
teeth, obligate bipedalism, etc.) or more exclusive (pygostyle,
toothlessness, keratinous beak, keeled sternum, alula, etc.) The only one
I can think of offhand that occurs right around the base of _Aves_ is a
reversed first pedal digit. "Wings" are also a possibilty (depending on
whether the non-flying ones of _Caudipteryx_ and _Protarchaeopteryx_ are
synapomorphic with those of _Archaeopteryx_ and other _Aves_ or not).

This is the primary reason why splitting _Aves_ from _Dinosauria_ is not a
great idea.

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