Some of the latest thinking about T. Rex was that it was a scavenger of carrion, rather than a predator.

"I believe it was a scavenger pure and simple because I can't find any evidence to support the theory that it was a predator," paleontologist Jack Horner said at the opening on Thursday of "T-Rex -- the killer question."

Horner, the inspiration for scientist Alan Grant -- played by Sam Neill -- in Steven Spielberg's "Jurassic Park," said the lumbering giant was too slow, its arms too small and its sight too poor to catch anything moving.

Another fact from childhood down the drain. Fantasia will never be the same.

[Update on Friday at 4 PM PDT]

Reader (and Transterrestrial site designer) Bill Simon points out this discussion on the subject raging in the comments section.

I am curious, however, as to how they can infer the eyesight quality of the beast. I suspect it's a guess based upon the distance apart of the eye sockets, which really only tells us how far apart the eyes are. There are current reptiles that are successful predators, despite being believed to have poor eyesight. Don't give up all hope.

They infer the eyesight from the size and shape of the brain, as determined by negative image from the size of the brain cavity. In T. Rex, Allosaurus and similar tyrannosaurids, the sensory area for smell is very large, and the sensory area for vision is small.

There are two real and unanswered questions that need to be answered before the question is closed: how fast were the tyrannosaurids, and were their arms feathered? If they were fast (and there's evidence both ways), they could have run down prey. If their arms were feathered (and keep in mind that they are very closely related to birds), then they could have used their arms for maneuver, rather than grasping, and the predator hypothesis would continue to be valid.

Horner has a reputation for being out on the leading edge, and it's very possible that he's correct. But I think it's too soon to tell.

If memory serves correct (which is a rarity these days), I seem to recall that this matter has been brought up on numerous Discovery Channel specials on dinosaurs over the past few years. I'm confused as to how this is now "news", unless it's the first time it's been presented in a full-fledged exhibit, rather than on a cable television show.

John's right, last winter I saw the program on Discovery where Horner spoke extensively. His conclusion was that T-Rex was a sort of super hyena scavaging the kills of other predators. The basis for this view is: 1) T-Rex's tiny, and apparently useless, forearms; 2)a leg structure incapable of speed (as compared to other predators, and; 3)large olfactory lobes in the brain, similar to a vulture's.

Well, I didn't mean to necessarily imply that it's news--just that it was news to me. I haven't been following the field that closely.

So that diorama at Disneyland is all wrong?

I didn't mean to imply that you considered it news, per se. I was just pointing out that it was in today's paper, meaning that some publication somewhere thought of it as "news". It seems to be a trend with those publications across the pond, picking up on new events appoximately 4 months or more after the fact (I recall that one of the papers over there reported the Honda Motion Machine commercial, and how it was made, as something groundbreaking and new in June or July, even though the story had broken in February or March.).

I say BS, I would put my money on a Komodo dragon type predator. Wound the prey item then wait for it to die. As far as the tiny forelegs I invoke the 2nd Law of animal behavior, when examing an animal you find an organ or appendage that seem to serve no useful purpose, they are used for sex.
OT, local (orlando,fl) news reports NASA is considering to move shuttle landings to CA for safety reasons.

I like what the comic-strip character Calvin had to say about this in this report he delivered to his class: "I say tyrannosaurs were predators, because it would be so bogus if they just ate things that were already dead. The end."

What safety reasons would those be? Have they suddenly decided the runway at the Cape is too short?

That'll increase costs and slow turnaround (though people in LA will get to hear the booms a lot more...)

They don't want people beaned by debris if another orbiter breaks up on re-entry. One could be a cynic and think that if it happens again that deep ocean might help to CYA. The report was on wftv so it might be on their website now. http://wftv.com

I would say put this story on the back burner and see if they still give it any credit in 10 years.

There are way too many scientists who are eager to say that they know what's going on when the reality is nobody has enough data.

I saw a show at UCBerkeley two or three years ago that portrayed T-Rex as a super-hyena. The main points were the small arms make it impossible or unlikely for t-rex to break his fall which would have made running particularly lethal and thus unlikely. Combine that with extra strong jaws which are good at getting at all the 'hard to get meat'.

The thought was T-Rex arrived at a kill and scared away the actual hunters and then ate whatever was left.

Needless to say I'm not entirely convinced. The whole arguement seems to stem on T-Rex being a clumbsy runner and I'm not sure how we would know that or not.

It doesn't require him to be a clumsy runner, just one that's imperfect. He can't afford to fall even once.

Something is wrong with this picture. Evolution yielded the T-Rex with the body design and size it has. These characteristics were selected for and therefore it was (highly) favorable for T-Rex to be built as it was built. I have difficulty accepting that T-Rex is such a flawed design that a single fall kills the animal or, once down, that it could not stand up. How could it have ever been viable?

By it being very unlikely to ever fall.

I haven't analyzed it, but I'll bet that, given the distribution of mass in its body and those powerful leg muscles, it's got a very low center of gravity, and would be very hard to knock down, and unlikely to stumble that badly, as long as it didn't run. It might have used the jaw for eating, but its main weapons might have been its powerful legs, that it could use to simply kick the smaller predators away.

I don't necessarily but it myself, but it's not totally implausible. To me, a more interesting question is what its resting posture would be, and when and where would it sleep?

I'm reminded of the Far Side cartoon with one bear telling another "C'mon! Look at these fangs! Look at these claws! You think we're just supposed to eat nuts and berries?" I think the theory of T Rexes falling to their death from tripping is destined for the same bin as the aerodynamic impossibility of bumblebees. It's not like a brontosaurus (apatosaurus is such a dumb name) was a speed demon either.

The interesting question remains, though, why the tiny, almost vestigial forearms? It seems to me that a predator would want something more useful than that.

Do they have any purpose at all? Would they have eventually disappeared completely?

A thought regarding those little arms: It seems that they may have been useful if the animal crouched down to rest (or drink water). With the hind legs folded (rather than extended as we always see them), the arms may have keep the chest from contacting the ground thus allowing normal breathing. If this is the case, the little arms are just the right length. I am not sure of the articulation of the wrists. But if the two-fingered "hands" bent such that the fingers rested flat on the ground, then the spred fingers would offer more stability to this function. It would also distribute the weight over a larger area. In this role, I see the forearms being used more for balance than direct support.

"Another fact from childhood down the drain. Fantasia will never be the same."

While we are on the subject of Fantasia...

We know that T-Rex and company went extinct 65 million years before humans appeared. So it would be absurd, to say the least, to depict T-Rex with humans. Right?

Then consider this: Fantasia's depicted struggle between a Stegosaurus and T-Rex was even more preposterous because Stegosaurus went extinct 80 million years before the appearance of T-Rex! But granting artistic license, I still like Fantasia.

Fantasia's depicted struggle between a Stegosaurus and T-Rex was even more preposterous because Stegosaurus went extinct 80 million years before the appearance of T-Rex!

Picky, picky, picky.

To paraphrase Senator Proxmire, "a million years here, a million years there, pretty soon you're talking about real time..."

I think the little arms are best compared to the wings of an ostrich. Unneeded for most practical purposes. Nobody worries about Ostriches falling over and dying when they go running about all day.

A clumbsy T-Rex's would be less likely to breed.