Theropod legs and hadrosaur skulls

[Martin Baeker <martin@turtle.ifw.ing.tu-bs.de>]

Dear all,

I just returned from a trip to madrid where I visited the natural history
museum. Two things there puzzled me rather greatly:

1. There was a mount of a carnotaurus in what was probably meant as a
running pose, one leg extended to the front and one backwards. What looked
very strange to me, however, was that the front leg was totally straight,
i.e. the femur, tibia and metatarsals were lying nearly on a straight
line. From PDW I supposed that this is not possible during locomotion. So
is there something special about Carnotaurus or is the mount simply wrong?
If the latter, how far could the leg be straightened?

2. There also was a hadrosaur skull (stupid me forgot to look up the
genus, it looked like an Anatotitan/Anatosaurus). So far I always
thought that the teeth of the lower jaw would be inside those of the upper
jaw (as it is in Iguanodon), so that on closing the mouth the upper jaw
would move outwards. The mount, however, had the lower jaw wider than the
upper jaw. Is this correct? If so, when did this change in jaw structure
occur?

Martin.

                   Dr. Martin Baeker
                   Institut fuer Werkstoffe
                   Langer Kamp 8
                   38106 Braunschweig
                   Germany
                   Tel.: 00-49-531-391-3073
                   Fax   00-49-531-391-3058
                   e-mail <martin.baeker@tu-bs.de>