Re: Fibula and Bone of Theropod

[William Hinchman <bsaurus@bellatlantic.net>]

siriraks arrathrakorn wrote:

>I am not paleontologist but I am interesting in the dinosaur-origin of
>bird. I have some questions.

>1. Is theropod have bigger fibula than bird and archaeopteryx?

>2. Are there any dinosaur that is not theropod and have hollow bone?

>3. What is pterosaur?

In Non Avian Theropods such as Carnosaurs and Ornithomimids etc, the
Fibula is a complete structure, although reduced somewhat in size in
smaller forms.  In Birds, the fibula has further reduced in size and I
belive in most modern forms, is no longer connected at the posterior
end, simply tapering to a point.

I've not aware of any Non Theropod with hollow bone structures, other
than crests/head ornamentation in the Lambeosaurs, perhaps other members
could further this line.

Pterosaurs are a part of the Archosauria, the "Ruling Reptiles",  Along
with Dinosaurs, and Crocodillians (some may also include Thecodonts
here, as a fourth member of the group)  Pterosaurs are considered to be
the closest relatives of Dinosaurs, the Hinged ankle joint being shared
creating a group called Ornithodires I believe.  Pterosaurs as a group
have a hyperextended fourth finger, which forms the majority of the wing
structure.

Hope this helps,

Bill Hinchman