For what it’s worth, which isn’t much, one of the early Ultimate Fighting Championships had a match between a karate guy who came in at a bit over 200 lbs and a sumo who came in at a bit over 600 lbs. I suspect it went something like the OP believes a confrontation between the dinosaurs in question would go.
The smaller, faster and more aggressive critter did, indeed, manage to take down the much larger (though the ratios aren’t particularly close) and less agile one.
He also broke his hand in the process. Seriously injured predators don’t have a long life expectancy.
Predation’s a lousy job. Nobody goes looking for extra work.
Uh, because we have lots of fossils of hadrosaurs from which we can conclude that it was a successful species from which we can conclude that it had a successful means of evading predation?
I mean, if it was that much of a mismatch in favor of the carnosaur, they would have eaten all the hadrosaurs in a week and we wouldn’t have any hadrosaur fossils. Basic logic.
They could have. And they probably were close. But the hadrosaurs were smaller, so were probably more agile and a bit faster. It’s not a guaranteed defense and would sometimes be caught, but the odds were probably with it.
So we’re looking at a factor of seven in weight, between the Big Brontos and the largest contemporary predators (thanks for the numbers, Evil Captor). Other than humans, are there any predators today which routinely take down prey seven times heavier than themselves? Even pack hunters vs. solo prey, I don’t think that happens.
Speaking of “Big Al”, the BBC did a pretty good CGI show of its life based on the injuries. It features a really good scene depicting a pack of allosaurs attacking a herd of diplodocids, which could be of interest in this discussion.
It is worth noting that in the “Big Al” story noted by Grendel’s Father, the hunting strategy used by the CGI allosaurs was to cause enough chaos to divide the herd, hoping to separate off a young/sick/weak member of the herd. They most emphatically did not start leaping atop healthy adults! Such a strategy is quite plausible (assuming the pack behavior of Allosaurus), and tends to minimize the risk to any individual allosaur (but by no means remove it; I seem to recall that the “job” of at least one of the pack members was to run through the middle of the herd in an effort to panic them - all while trying not to get stepped on in the ensuing confusion).
Then once they had one alone they hung back from it a bit and took turns pestering it untill it was too exhausted to fight before they moved in for the kill. Big animals are rather vulnerable in this way. A rhino can be killed just by chasing it untill it drops dead from shock.
Wolf packs have been known to take adult moose ( usually older diseased, incapacitated, or snowbound animals ), but generally prefer smaller species of deer ( a white-tailed will clock in about twice the size of a wolf ). African Hunting Dogs will take adult wildebeest and zebra ( again usually older, diseased animals ), but generally prefer smaller antelope like Impala ( again about twice the size ). Spotted hyenas regularly take wildebeest and zebra, but they’re twice the size of African Hunting Dogs and the ratio is more like 3-4 times, not seven ( largest adult hyena at about 180-190 lbs, vs. largest adult species of zebra at around 750-770 ). Both lions and spotted hyenas are very cautious about tackling truly massive prey like Cape Buffalo, though it happens.
But I’ve seen lion photos of shattered jaws from zebra kicks that doomed the animal to slow starvation.
Thinking about the analogy between humans, I realize the problem is that humans have the same body plan. I mean, sauropods were basically blobs of fat on stilts with a head and neck slung out fore and aft. The didn’t have arms and legs that could easily and quickly swing out to protect the body.
The points about culling out the sick and the weak are good ones, but I still see the sauropod body plan as so defenseless that even a healthy, mature individual didn’t have much power of self-defense. I still think an allosaur could easily have cruised in, taken a big nasty swipe at a mature apatosaur before it could react or escape, and then wait for it to weaken and die. Going after the sick and the weak would have been pointless when the healthy are so unable to defend themselves.
As for Neurotik’s claim that my saying that many posts assume an even keel between predator and prey indicates that I’ve not been paying attention – does NOT. I was referring to the fact that people seemed to be saying that sauropods were as fast as carnosaurs and could whip out a tail or lash out with a leg fast enough to crush them. I’m not buying that. I visualize it in my head and it just doesn’t make sense – fleshbob whips out treetrunk leg lightning fast? Mmm, nope. I’ve seen how elephants look when they walk. They look slow and careful. I imagine sauropods would have been slower and , um, carefuller.
In any event, I stated in my OP that it’s obvious sauropods were a successful species, so there’s no reason to get all cranked here. I just don’t buy that size and body plan as a successful defense. Maybe they were poisonous or smelled really, really bad or had stinging tentacles. Hey, with their massive stomachs they could probably have produced some killer farts. If they had some kind of organic way of lighting them, we have a natural flamethrower defense. That would have been something.
Thinking about it, maybe the real function of that “second brain” at the base of the spine was to allow the tail to function superfast and (relatively) intelligently.
That “second brain” doesn’t exist. Please read up on what dinosaurs were actually like and then come back and try for an intelligent conversation. People who know more about dinosaurs than you have given you the answers to which you seek, but you just won’t accept them due to these bizarre, inaccurate preconceived notions that you can’t seem to let go of.
Here is something else which I don’t believe has been touched upon yet. In general, animals do not expend excess energy unless absolutely necessary. This is why a Cheetah doesn’t do 70 all the time, only when it’s about to go for the kill. Now, what would take more energy- going after a big hulk like an apatosaur which, as has already been stated, has both a weight/size advantage and most likely a tough skin, or going after a smaller creature that would present far less of a challenge? It would simply not be beneficial for the animal to waste the amount of energy it would take to get one of the big guys if it would take far less to get a couple little guys.
Gee, Neurotik, I didn’t think insulting remarks were appropriate in General Questions. I never set myself up as an expert on dinosaurs, and I’m not, it’s true. But I’m not OBLIGATED to accept explanations from others if they don’t make sense to me. Others are free to think I’m being pig-headed, too, but it’s possible to do so in a civil manner.
In any event, believe me, you need not trouble yourself at all on my behalf. Given the generally sour tenor of your comments, I won’t miss your posts at all.
So, rather than accepting explanations based on what are known to be valid defenses in the animal kingdom, you’d prefer an explanation that resides in the realm of fantasy…?
Let’s recap, shall we? Defenses available to the typical sauropod include:
[ul]
[li] Large size. Yes, like it or not, being big acts as a good deterrent to many predators. It works for moose, elephants, hippos, and even whales. It would have worked just as well for Apatosaurus. If you’ve got a lot of weight to throw around, it’s gonna hurt when it lands.[/li][li] Herding behavior. There’s safety in numbers. Again, lots of herbivores herd for safety. The exact “cause” of the safety may vary from it being less likely to pick any particular individual out of a crowd to active, organized defense by herd members. [/li][li] Tail-whips. Perhaps the most speculative of the lot, since we don’t really know how effective the tails would have been as whips. Even if Apatosaurus didn’t use them to strike predators, the noise alone might have been enough to startle or give any approaching predator pause.[/li][li] Height advantage. Being able to see them before they see you, or at the very least, give you advance warning that hunters are coming is always a good thing.[/li][li] Good senses (sight, hearing or smell). Many sauropods had nares in odd places (near the top of the skull), which may have allowed for a heightened sense of smell.[/li][li] Thick skin. While not as good as boney or keratinous armor, thick skin can certainly help minimize the damage done by a less-than-determined attacker, or by grazing attacks.[/li][/ul]
As Arken has just alluded, these together can make Apatosaurus unappealing enough in many circumstances, especially if there’s easier prey to be had, that an Allosaurus might simply not even bother. At the very least, the above would have served an adult Apatosaurus quite well.
And, lest you think Allosaurus had it easy, here is a list of injuries sustained by the aforementioned “Big Al”. As noted in that link, many allosaur specimens show similar wear-and-tear, indicating that the life of a carnivore is not all fine-dining and relaxation.