Re: Big Dinosaur Prints Found

["Demetrios M. Vital" <vita0015@tc.umn.edu>]

> Wow.  This pretty much blows away everything I thought I understood
> about dinosaurs (again :-) I can imagine how a lazy sauropod could
> leave a tail-drag -- the older sauropod mounts looks believable in the
> posture they give the dragging tails.  But a theropod?  When I think
> of the shape of a _Dilophosaurus_, the only way I can see it making
> any kind of drag mark is if the body is held in a best 1959s-style
> upright posture.  Is that what was going on here?  Or are theropod
> tails more dorso-ventrally flexible than I'd thought?  And if so,
> didn't it entail a lot of (wasted) muscular effort to keep them off
> the ground for the 99% of the time that they seem to have been held
> there?

Like you said, the animal had to be upright in order to drag the tail, like
a see-saw.  So it is balanced when positioned horizontally, and doesn't
require that extra muscle effort.  Wasn't it mostly ligaments, anyway?

And a trackway is a snapshot of dinosaur behavior, as well as a footprint.
We have no idea what was happening at that instant.  Maybe a mating display?
Maybe trying to look imposing by getting taller?  Who knows.  It obviously
does not indicate a normal activity, because no other trackways of this
animal show this.  This doesn't necessarily change anything about the
morphology of dinosaurs.

-Demetrios