[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

answers to the bipedal ptero challenge

Scott wrote:

     I'll try to get a better character list later (I have to be in
class in 20

but 1) pterosaurs can't move bipedally like dinosaurs because they a)
have their center of gravity in the right place for a horizontal

>> answer: IMHO the center of gravity in pterosaurs is close to the
notarial section of the dorsal series, just posterior to the glenoid.
The toes can be brought beneath this point in a balanced bipedal pose. I
can send you drawings if you still doubt. If the center of gravity were
near the hips, as in theropods, then pterosaurs probably could not

fail to enlarge their illia anteroposteriorly like theropods do.

>> answer: IMHO, pterosaur ilia are enlarged anteroposteriorly as in
theropods, incorporating more than the diapsid minimum of two sacrals.
In Pteranodon I think the number reaches ten and in ctenochasmatids the
posterior ilium is elongated as much as the anterior portion.

2) they don't show the adaptatins to upright bipedalism seen in
especially the double curve in the sacral series.

>> answer: IMHO this is a different sort of bipedalism. Not of the
diapsid sort and so is not a good analogy.