[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]
Re: Scansoriality in Scansoriopteryx?
Michael Lovejoy (firstname.lastname@example.org) wrote:
<Just a quick question to anyone who has an opinion: Why is
Scansoriopteryx thought of as arboreal? What evidence is there? (HP
Jaime's post just confused me even more: arboreal feet and terrestrial
hands? Sounds more like a percher than a climber.)>
The main reasons I have been given were that the arm was really long
with a physical adaptation seen in some primates or in birds, indicating
it was arboreal. I do not buy their reasons.
<PS Does this animal (or Epidendrosaurus) have an SLC? (or any other
evidence of arm-folding ability)>
Here's the thing, there's a small carpal in the wrist of Czerkas'
specimen; it is semicurcula in form, and there's what appears to be a
trochlear groove, but it's not on the curved side but on the flat side. I
have restored this as a semilunate carpal, however, just to be safe. The
distal ends of the radius and ulna appear to be crushed, they are broadly
flattened with fracturing on the surface, and I do not trust their shape
more than I could throw the thing. If there was an arm folding ability, it
was minimal, and the glenoid faced ventrally, not laterally, and certainly
would not have permitted over-shoulder rotation of the arm as was
hypothesized by Zhang et alii for *Epidendrosaurus*. You would think with
a hand like that it would have folded better, but this may be due to its
possibly "non-adult" nature.
Jaime A. Headden
Little steps are often the hardest to take. We are too used to making leaps
in the face of adversity, that a simple skip is so hard to do. We should all
learn to walk soft, walk small, see the world around us rather than zoom by it.
Do you Yahoo!?
New DSL Internet Access from SBC & Yahoo!