There was a theory going around a few years ago: a noted paleontologist was putting it about that Tyrannosaurus Rex--one of the most utterly monstrous creatures ever to stride the Earth--was no more than an undignified grovelling scavenger.

I disagreed, and was moved strongly to illustrate the point.

Sure, many predators will scavenge if they get the chance, but most of the time they have to hunt. Usually they use the element of surprise, as we see with crocodiles, lions and other cats, eagles, bears, wolves, etc... and as I have shown with T.rex here.

Furthermore, there is always a predator for every grazing animal species, and a TOP predator in every ecosystem. T.rex was the biggest carnivore in its region -- if it wasn't killing the gigantic herbivores, then nothing else could have.

It's fashionable to depict dinosaurs as being very lean, to the point of looking anorexic; but a biped the size of a fully grown T-rex would have required enormous leg muscles in order to lunge from hiding, and to walk at a reasonable pace; powerful legs would also have been necessary to balance the violent flesh-tearing movements of the head and neck during attacks (such as depicted here).

It's unlikely, given its proportions, that the adult creature could have run at appreciable speed -- yet another argument strongly supporting the ambush theory.

I do suspect that younger T.rexes would have been faster runners, and possibly hunted in packs. The monster shown here is an oldtimer, evidently capable of bringing down a Triceratops on its own.

The Attack:
It seems remarkably unlikely that T.rex would have approached Triceratops from the FRONT, although this scenario is often depicted in paintings. It's far more probable that Rex would have lurked in dense foliage and lunged out at the passing horned brute from the side. The Rex in my painting is attempting to pull the trike down for an easier kill; but the trike seems to be responding quickly, wheeling around to gouge his attacker... how will it end?

Expressionism:
These are extreme monsters and I'm trying to convey primal fury rather than going for the sedate 'these-were-just-regular-animals' approach. At the same time, I'm not aiming to be scientifically inaccurate in my renderings, but am attempting to portray behaviors and situations that I believe are likely to have occurred.