Re: Paedomorphosis ( Re: BARYONYX' CLAWS )

[Dinogeorge <Dinogeorge@aol.com>]

In a message dated 98-04-10 17:35:22 EDT, m_troutman@hotmail.com writes:

<<But, all speculation aside, a bird has to have 
several osteological features for flight.

1) Acute scapulacoracoid angle. 
2) Posteriorly facing coracoid with a peg-like or weakly strut-like 
shape.
3) Single sternum.>>

Pretty sure _Archaeopteryx_ lacks two out of three of these (1 and 2--I'm
going by Larry Martin's 1991 description here, in which he comments on
_Archaeopteryx_ as having a "coracoid that does not differ greatly from that
of other theropods"), while many flightless theropods did have (3).
_Archaeopteryx_ certainly was able to fly--though not like modern birds
fly--so your thesis that flight is impossible without these features needs to
be reexamined (to say the least). Do not limit yourself to describing as
"flight" specifically the kind of flight that modern avians have; try to
imagine what kind of flying dinosaurs such as _Archaeopteryx_ and earlier, as
yet unknown forms might have been capable of.

<< These features all withstand the stresses of flight brought by the 
 musclature. Bracing is absolutely essential for flight. Since all known 
 theropods do not show these features it is unlikely that they modified 
 the hypothetical "Triassic flight apparatus".  >>

You are rapidly approaching the "flight is a miracle" school of current
dinosaurology. Of course theropods lacked the well-developed flight apparatus
of modern birds. It hadn't yet evolved when the typical theropod groups began
to diverge from the lineage that led to modern birds.