R: Archaeopteryx chimaera

["Alessandro Marisa" <amaris@tin.it>]

-----Messaggio originale-----
Da: tsg94001@uconnvm.uconn.edu <tsg94001@uconnvm.uconn.edu>
A: dinosaur@usc.edu <dinosaur@usc.edu>
Data: lunedì 22 febbraio 1999 18.00
Oggetto: Re: Archaeopteryx chimaera

>Does anybody know why certain theropods (dromaeosaurids, birds,
>therizinosauroids) have the pubis pushed back?  I have heard that
>ornithischians have an opisthopubic pelvis because it makes space for a
>bigger gut (always helpful when digesting cellulose-rich, nutrition-poor
>plant matter).  This could apply to therizinosauroids too, but why did
>dromaeosaurids and birds do it?


I don't known for Birds but the modification in the pubis of Deinonychus is
too unusual for a Theropoda, but if you consider that also the femur is
modified (there is a supplementary process on the posterior border)
identified as the scar of a big retractor muscle of the leg. All the two
features is considered an adaptation for using the claw on the pes as a
weapon.

By and sorry for the english
Alessandro Marisa
"Voluntary of Paleontology Group of Monfalcone"
Via Achille Grandi n°18
38068 ROVERETO (TN) ITALY
Tel: 039-0464-434658 Email: amaris@tin.it