[StJacques]

"As I recall, one of Horner's arguments about T-Rex as a scavenger is that he thought T-Rex wasn't built as much for speed, but for long distance walking.

I've always thought that T-Rex didn't need to be fast, just faster than the prey animals. Nobody ever seems to ask Dr. Horner THAT question. If T-Rex was following large numbers of migratory prey animals, then one would expect that it would be made to walk long distances, and attack sick prey animals with short bursts of speed."

I agree with everything you posted here ex-NFO and I too am convinced that T Rex was a predator. When I asked myself what I would expect to see in T Rex that might indicate that he was primarily a scavenger I looked for traits I might commonly associate with scavengers today, such as long thin necks (condors, vultures e.g.) uncommon to predators -- T Rex's neck was very broad which I believe gave him an advantage in bringing down large prey in close contact; a mouth (or bill or jaw if you will) that was primarily designed for ripping and tearing rather than biting and crushing -- most scavengers have hooked bills with small razor-like teeth that rip unlike T Rex; and most importantly a relatively slender thoracic cavity like condors and vultures again -- can you name one robust scavenger? -- since scavengers must be able to endure relatively long periods with little or no food. T Rex had an extremely robust body that had to be sustained with an enormous amount of protein and I find it difficult to believe than any scavenger species could evolve in any environment capable of providing a protein supply sufficient to sustain that kind of bulk.

I am much more likely to associate T Rex with present-day predators such as alligators and crocodiles, who it seems to me have teeth very similar to T Rex. Both alligators and crocodiles depend upon predation as their basic means of survival, but they both will also scavenge when the occasion presents itself.

[Al Simmons]

Alligators and Crocs have conical teeth; TRex had teeth serrated like steak knives. No comparison. TRex's teeth are the deadliest terrestrial predatory arsenal in the earth's history (that we are aware of at this time....)

[grey_whiskers]

T Rex had an extremely robust body that had to be sustained with an enormous amount of protein and I find it difficult to believe than any scavenger species could evolve in any environment capable of providing a protein supply sufficient to sustain that kind of bulk.

I like your reasoning. Here's another couple of relevant questions to consider, to which I haven't the foggiest clue of the correct answer.

Did the sauropods commonly held to be prey for T-rex & other large predators travel in herds?

Were they hunted by lone T-rex assailants, or by packs?

When a sauropod was brought down, how much meat was left over for scavengers to pick over? Just possibly--I don't know, nor am I even confident in my guess--a lone T-rex might gorge and leave XYZ tons of meat on the bones. OTOH, a pack/herd/pod/gaggle/wtf of velociraptors, or several packs, might successively pick the bones clean shortly after the kill. That brings to mind another question.

Do we know the "pecking order" for scavengers following the kill of one of the sauropods?

If you had the occasional XYZ tons of meat lying around in heaps, and T-rex was a scavenger, but near the top of the pecking order, then I guess getting the requisite protein wouldn't be as much of a challenge.

If there are any true paleo's around here, though, they should be able to tell me in a matter of microseconds just how bad of a rectocranial inversion I have, even to have asked those questions.

I defer to their judgement...

Cheers!