[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]
Re: Feduccia ORIGIN
> He isn't saying that an "already-flying" animal is required for the
> development of feathers, but that feathers evolved not from a
> short-forelimbed, cusorial predator (such as an early dinosaur), but
> from an arboreal, long-forelimbed diapsid.
He seems to be ignoring the possibility of a long-forelimbed, arboreal
Long-forelimbed we have, and in forms apparently close to the ancestry
of birds. We call them deinonychids. Other, slightly more distant,
examples include troodontids and ornithomimids. What is the relative
arm size in dryptosaurids???
To me a small arboreal troodontid or deinonychosaur seems quite
possible. (In fact I am not sure I can confidently say _Troodon_
itself is NOT arboreal).
> He's saying that it's difficult (and perhaps impossible) to
> construct a sound model whereby feathers evolved in a ground-up
This assumes that feathers evolved originally for aerodynamic purposes
If feathers originated to provide insulation, than arboreality is
Now, I *do* agree that evolution of flight from a non-arboreal ancestor
is unlikely, if it is evemn possible. But I do not see how this rules
In short Feduccia is erroneously combining the ground-up theory of the
origin of flight with the dinosaur theory of the origin of birds. The
two are not necessarily attached.
The peace of God be with you.