Re: sauropod arm articulations

["David Marjanovic" <david.marjanovic@gmx.at>]

----- Original Message -----
From: <GSP1954@aol.com>
Sent: Friday, October 03, 2003 4:53 AM

> All restorations showing the scapula-coracoid subhorizontal are grossly
> incorrect.

At the moment I can't find the SVP meeting abstract (2002 or 2001, IIRC)
which claims to have found a groove on sauropod ribcages into which the
scapula fits -- in a position that is a bit more horizontal than "normally"
thought. Can someone help me...?

> In virtually all tetrapods the scapula is sub-vertical, vertical, or
> even  tilted forward.

With Avepectora being the exception. Or perhaps with Dinosauria being the
exception. Those odd curved hadrosaur scapulae follow the curvature of the
vertebral column in articulated specimens, don't they?

> Horizontal blades are found in flying archosaurs with strongly flexed
coracoids
> [...] that articulate with the front end of the horizontal sternum.

I've always seen the coracoids of *Iguanodon* restored as contacting the
front edges of the sterna... and the medial edges of each other as well,
with the irregular "intersternal ossification" filling out part of the
lozenge-shaped hole between the 4 bones. Interestingly, this "intersternum"
is the only hint I've ever seen that your "cartilaginous episternum*" is
real.

* Unfortunately the term "episternum" is sometimes used for the
interclavicle... which is a dermal bone and therefore never cartilaginous.