Ground-stalking teratorns

[Eric Hall <Hall966@msn.com>]

I haven't had any luck finding Campbell and Tonni 1982 and 1983 online, and 
my local library is under construction, so while I wait I was wondering if 
anybody knows their reasons for seeing teratorns as ground-stalking small 
animal predators?  This doesn't seem to make sense to me if Merriam's 
teratorn is known in large numbers from the tar pits, which would certainly 
imply heavy scavenging, would it not?
I found some info on an untrustworthy-looking ornithological website that 
vaguely suggested one of the reasons for this theory was that teratorns had 
more kinetic skulls than say eagles, less suited for dismembering prey and 
more for swallowing it whole.
Anybody familiar with this argument?

Eric Hall