Re: Upright bipedalism in dinos

[John Schneiderman <dino@revelation.unomaha.edu>]

> 
> There is one group of birds which is somewhat exceptional in both regards: 
> the penguins.  Their stance has changed to a far more vertical, erect 
> posture, more like that of hominids than that of any other dinos or birds 
> that I can think of.  However, although they are capable of erect walking, 
> they also propel themselves on their bellies in a modified quadrupedal manner 
> on ice (or is this better described as non-pedal locomotion?), and of course 
> swim horizontally in a manner which to my way of thinking could be called 
> quadrupedal (although swimming is clearly a special case of locomotion).
> 
> My question:  are there any known fossil dinos which may have had an erect 
> posture similar to that of the penguins?  The secondary question would be: 
> are there any other birds (ancient or modern, other than those leading to the 
> penguin line) which show similar adaptations (primarily erect posture, but 
> also horizontal/quadrupedal locomotion)?
> 
Penquins have the nearly vertical posture due to its body shape adapted 
for the cold weather (surface area) and adapted from its marine habitat.

I know of no non-avian Dinosaur which fits this adaptation but the diver 
bird Hesperornis is close.  But Hesperornis body plan is a result of its 
marine habitat not temperature requirements.

---John Schneiderman (dino@revelation.unomaha.edu) "dinophile"