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Re: Feduccia's Errors
> The similarity of the pubes of Archaeopteryx and theropods are dismissed. In
> fact the pubic shafts of the former and dromaeosaurs share a plate-like,
> slightly angled transverse cross-section not found in any other archosaurs.
Yeah - in fact if Dromaeosaur pelvises had been known back when
the dinosaur orders were named, they might have gotten the name
> AF states that the "thecodont" Postosuchus is close to the origin of
> carnosaurs. This view is held by few if any today. All crurotarsal
> ankled archosaurs such as Postosuchus belong to the group that
> includes crocodilians, so Postosuchus is a near crocodilian, not
> a near dinosaur.
Urk, I haven't gotten that far yet. This is silly. The only other
person who I have seen recently espouse a similar view was Chatterjee,
when he suggested that tyrannosaurs were descended from poposaurids!
> I happen to agree with AF that birds almost certainly evolved flight from
> high places ... Where we diverge is
> in his unsubstantiated insistence that small theropods - despite many having
> long clawed fingers and bird-like toes - were not good climbers.
Indeed, _Compsognathus_ could, with ver *minor* modifications,
be as good a climber as a squirrel. (I think the specialized
two-fingered hand may preclude good climbing in that genus, but
it has enough close relatives with three-fingered hands to make
a form that differs mainly in retaining three fingers quite plausible).
> Of course, I have been guilty of committing a "fantasy" by illustrating my
> small theropods with feathers, for which "there is no evidence", and would
> hinder the running of a biped by producing drag
Gack. I am almost losing interest in finishing reading the book!
Feathers produce excess drag in cursorial forms!?!?!?! I guess
flying birds don't have to worry about drag :-)
> AF concludes that body insulating feathers are not necessarily correlated
> with endothermy despite the absence of a single living insulated endotherm in
> the modern world.
I assume a typo here - you mean no living insulated *ectotherm*, right?
As near as I can tell, insulation would actually be *detrimental*
to an ectotherm, as it would interfere with heat uptake from the
environment. (Insulation does work both ways, after all). Imagine
how much longer a basking lizard would take to warm up if it had
feathers or fur.
A full body covering of insulation pretty much *requires* that
heating be almost entirely internal, and thus makes the animal,
by definition, an endotherm.
[If we can find a Sinosauropteryx specimen which shows insulation
off of the mid-saggital plane, then I would say endothermy in
small coelurosaurs is firmly and finally establshed].
The peace of God be with you.