Re: Lack of Running Giant Theropod Tracks

[Augusto Haro <augustoharo@gmail.com>]

2010/12/2 Sim Koning <simkoning@msn.com>:
>
>  Adult tyrannosaurs, although slower, would have been able to kill 
> ceratopsids and ankylosaurs, animals that the juveniles may have been too 
> weak and blade-toothed to exploit. However, making a living by attacking 
> something that is not only your own size, but also able to kill you as easily 
> as you could kill it, may not have made for a very survivable lifestyle.

This does not seem easy to infer. For example, the weaponry of a rat
or squirrel (their incisors) make them probably very dangerous for a
similarly sized predator, yet many weasels make a living mostly of
eating these similarly sized rodents. If we only know the skeletons of
the impala and cheetah, whe may think they were similarly armed and
would expect the match to be even--a gracile version of the
Triceratops-Tyrannosaurus duel. Yet, most of the time the cheetah is
not harmed by this habitual prey (granted, their proportions suggests
they were more engaged in running that fighting). Perhaps herbivores,
because of being confronted intraspecifically less often than
carnivores, are not as experienced (a carnivore in theory engages in
conflict more often, each time it has to eat and there is no carrion
around).