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Re: Dino reputation 'is exaggerated'




On Oct 13, 2005, at 5:47 AM, Jorge Dichenberg wrote:

--- don ohmes <d_ohmes@yahoo.com> wrote:

Seriously, sauropods were slow, weren't they? And if
Velociraptors could climb trees, why couldn't they
climb a startled sauropod?

Imagine a cat trying to climb a cow and kill it. Improbable, isn't it?


If that kitty cat had claws the size of a Velociraptor, I wouldn't want it stalking me. Ever get a Maine Coon Cat mad at you? Bad Plan! (If you are not aware of Maine Coon Cats, do a google search and be surprised). Attitude accounts for a lot more than physical ability sometimes.

Wyoming has it's own perspective
Here in mountain lion country, I constantsly am aware of the possibility of one jumping me when I have my head in a fossil hole (and my back to the world) while working on a microsite. Anyone collecting alone up here runs that small but definite risk. Mountain Lions do take the occasional cow but usually do not survive the rancher. ( The big cat weighs 200 + pounds and the cow weighs 1200.) Bobcats locally take small sheep and lambs which are not too much smaller than they are. More to the point, a small pack of 20 pound coyotes will definitely take calves right out from under the (relatively huge) protective angus mothers nose. (the calf is bigger than the individual coyote and the mother is usually fairly worked up and pissy about the predation). I would not underestimate the ability of a smaller theropod(s) to take a larger sauropod (calf) using group warfare. Speed, persistance and endurance would be useful in overcoming any size difference. There is no question that the anatomy of most Dromaeosaurids is not ideally suited for such activities but if you look at the coyote example, you will notice some similarities in anatomical deficiencies for such combat. Coyotes are not built ideally for taking animals larger than themselves but they do it anyway. Apparently, no one has told them they can't.


I think trying to bracket and limit activities of Mesozoic meat eaters is an interesting exercise but it is wrought with problems. You can speculate based on anatomy and be mostly correct but having said that..... Opportunity exists and in the autistic world of a mesozoic theropod, what you are built for and what presents itself were two different things. I am not sure that a lot of thought went into deciding what to eat and what not to eat. IMHO, physical intimidation and armor were probably deciding factors of what not to eat more than a slow huge sized fellow would typically transmit to the little predators. Remember that there were no fast food restaurants about and the only fast food was really fast. I think all of the theropods were opportunistic scavengers and most of them hunted as well but the emphasis was always on the easy meal when it was about. Tell me a hungry fellow who was a full time hunter will ignore an easy (smelly, pre-tenderized) snack laying about. Hunger is a motivating force for all animals. More hungry means taking more of a chance to get a meal. It is always a trade off for survival.

Frank (Rooster) Bliss
MS, Biostratigraphy
Weston Wyoming
visit www.cattleranch.org for lots of Hell Creek fossil photos

I was simulated and looked at skeleton of Velociraptor. There exists a living mammal matching amlmost all adaptations of it. It has big eyes, long skull, small sharp teeth, carries it's head forward, has big claws (although on foreleges, not hindlegs), long body, shortened legs and long tail which can be pointed vertically. It is predator, very active, lives in groups in sandy semi-deserts.

This description fits, surprisingly, a meerkat. Small
predator adapted to running in dense vegetation,
digging and climbing. Claws are used for digging and
climbing. Even combination of shortish legs and tail
which can be pointed upwards fits - it is used by
meerkats to keep visual contact in thick vegetation.

Pack of meerkats can be fierce. But they typically
hunt animals much smaller than their size.

In contrast, Velociraptor has adaptations
contradictory to modern big predatory mammals (ones
that hunt animals bigger than themselves). Big claw is
not supported by thick leg bones needed to withstand
forces when fighting prey. Modern big cats and polar
bears have much thicker legs and jaws. Velociraptor
has thin bones and elongated skull - not suitable for
wrestling. Head facing forward makes no sense in
animal confronting prey much higher than itself. Legs
are shortened which is not a good adaptation for fast
running or jumping. Extremely long tail would be very
vulnerable to breaking or indeed, biting by prey.

In short, it was a small predator, not a big one. For
Velociraptor, peaceful Dinotopia is better than
violent Jurassic Park. ;)

J.



        
                
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