Re: Sail vs Hump?

[Gertsch <lgertsch@slate.Mines.EDU>]

On Mon, 6 May 1996, Rob Meyerson wrote:

> However, the neural spines of bison, and some fossil pigs, are not
>  exactly short (although they are not up to _Spinosaurus_
>  dimensions.  Part of the hypothesis held that the spines helped to
>  support the tendons used in lifting the head (although the head of
>  the critter doesn't seem to be so large as to need the extra
>  pulling power).  The premise sounds similar to Bakker's hadrosaur
>  reconstruction, where the head couldn't be lifted above the hight
>  of the backbone.

Modern pigs are rooting animals, so although their heads don't look so 
large, they still need strong muscles (and significant attachment sites) 
to generate the high forces necessary to plow their noses through the 
ground.  As you'd expect, they also can't lift their heads above their 
shoulders.

I grew up on a pig farm, but for those of you not so blessed, the movie 
_Babe_ (and its imitators) offers a chance to see that last point for 
yourself.

Obviously, that's not the reason for bison humps.  One of 
several adaptations for head-butting, maybe?

Leslie Gertsch
research assistant professor
Mining Engineering Department
Colorado School of Mines
Golden, CO  80401