Re: The absurdity, the absurdity (was: Cooperating theropods?)

["Larry Dunn" <larrydunn@hotmail.com>]

Sankarah wrote:

>The Tugrugeen fossil shows a Velociraptor who seriously miscalculated. 
>There's no way that could be the norm, because that fella was doomed
>from the get-go.

We have a preserved dromaeosaur in the midst of a prey event which 
neatly explains the use of the sickle claw.  

On the other hand, we have a hypothesis of hunting based on no solid 
evidence other than the size of the claw (a claw apparently demonstrated 
in use per above), and which requires a great deal of optimism and 
speculation. 

Why do you prefer the second hypothesis?

>  That claw would be overkill on just about anything
>under a quarter ton; you can *bite* anything smaller to death with no
>problem, as shown by the innumerable other small therapods running
>around. 

You're presumably not proposing that the velociraptor could kill that 
protoceratops with it's jaws.  If dromaeosaurs hunted animals roughly 
their size or smaller (clearly the most reasonable hypothesis), why 
wouldn't they use their hind claw to cut carotid arteries?  Why not 
quickly slit the belly of a lizard or mammal before popping it in your 
mouth?  

Sure, small dinosaurs and other smaller life forms got their share, but 
that doesn't exclude dromaeosaurs in any way from a share (just as a 
variety of animals feed on mice today).

>As I've said, killing a Tenontosaurus wouldn't require much in the way
>of cooperation.  I jump, you jump.  I jump, you jump.  I jump, you
>jump.  Not very complex.  

You've left out many steps here.  

We have to get them all together without mutual antagonism (which, the 
evidence suggests, their brains seems to have been incapable of), and 
hungry at the same time.

We have to get them to select the same animal, particulalry difficult in 
the case of herd prey.

(You may reply that one just randomly picks an animal, and then others 
pile on, but that itself suggests that the first animal knows that 
others will assist it AND that the other animals know to assist the 
first animal).

We have to get them to attack the same animal in the shift pattern that 
you describe without interfering with each other (and, for that matter, 
without attacking each other).  This requires that they each patiently 
wait out their particular role in the attack (attacking when the 
tenontosaur is lurching toward the deinonychus that just hopped off), 
watching what the others are doing.

All of this requires even a bit more cooperation than most mammalian 
pack hunters display, rather than less.

>But that aside, I seem to recall hearing that they might not have been
>as dumb as previously assumed.  Studies in birds today show that 

(snip of bird study)

Even  assuming that's true, the smartest theropods weren't much smarter 
than the dumbest birds.  And even the smartest birds do not generally 
show much cooperation in feeding.

>> Yes, and that's because their forelimbs are suited for it.  Unlike 
those
>> of Deinonychus.
>
>I'm still not convinced.  See GSP's rendition in D:tE.

>Look at the picture and get back to me on this. 

Because an illustrator draws something does not make it so.  Greg Paul 
has also gone back and made the sauropods in his  illustrations  spiny 
because there's some purported evidence that *one* sauropod may have had 
spines.  

See the archives of this list.  Look for posts on the configuration of 
dromaeosaur forelimbs, particularly the limited range of their movement 
and their limited ability to grasp.

>Buffalo, bison, moose, elk, caribou, the occasional (brave) wildebeest. 
>Elephants.  All but one big guys with horns.  The last has tusks
>instead.  What do hadrosaurs have?  Zip.  They're just big, and not 
very
>threatening.

then, later,

>  T. had nothing whatsoever.  No bite to
>speak of, no weaponry, not even any hooves.  Not even mass.  That 
sucker
>*was* meat on the table.  

Until they crush your hindlimb or break some of your ribs or break your 
jaw or one of your forelimbs.  The lioness dying of a broken jaw knows 
that the un-horned, "helpless" zebras are not "meat on the table" (and 
let's not mention speed as a defense here because sufficient speed would 
have *prevented* the injury).
 
>>A lion whose jaw has been broken by a zebra was essentially killed 
>>by the zebra.
>
> You're missing the point here; it's a
>given that injuries will take the animal out of commission, but what 
I'm
>saying is that it's not that easy to injure one in the first place. 

Predators are so careful to pick out their prey in the first place, and 
their success rates are so low due partly to unfavorable circumstances 
at the time of contact, because they are not made of steel.  I'm sure 
you're not suggesting that predaors are generally reckless.

>> The scenario you describe takes a lot more coordination than most
>> *mammalian* predators employ!  

>Uh, 

An aside here. 

"Uh" is an internet mechanism used to insinuate that you're trying to 
think of some way to tell this poor idiot how wrong he is without 
utterly crushing him.  I've noticed that it's very popular with graduate 
students and other young adults (older folks will smile and remember a 
time when we had a little knowledge and thought we knew everything too!) 
.  I suggest that you don't do it.  Some of your future colleagues are 
reading.

>mammals use lures, stealthy approaches, ambushes, decoys, precision
>wounding, specific patterns of movement, and on again off again shifts
>in their attacks.  Unless you exclude all dogs, social cats, and hyenas
>from "most *mammalian* predators" the scenario I describe doesn't even
>come close to being coordinated.  If you do exclude those animals,
>what's left isn't social enough to count.

Yes, different species of pack-hunting mammals each use *some* of these.  
Lures (one animal drawing the attention of the tenontosaur while another 
hops on from the other side), specific patterns of movement and 
on-again, off-again shifts (attacking on both flanks; in waves) are some 
of these.  Don't minimize the complexity of what you're proposing 
dromaeosaurs did.

>>Even assuming for the moment that the killer raptor rationale for 
>>the dromaeosaur/deinonychus site is correct, it seems that 
>>tenontosaurus was prefectly capable of defending itself.
>
>Says who?  Who says the Deinonychus killed weren't killed due to their
>own ineptitude?  The Tenontosaur doesn't get points if it killed them 
by
>falling on them.

Says most of the killer raptor enthusiasts.  I am new to this hypothesis 
that the tenonotsaur, in its rush to die, fell on the three deinonychus.  
Did it fall on all three at once or did it fall, get up, fall, get up, 
and fall, each time squishing a deinonychus?

>>Were there no lizards to eat?  Smaller dinosaurs?  Mammals?  Seems 
rather fantastic to me.

>Uh,

A two "Uh" message.  I must be *really* dumb.

> they were grabbed by the myriad other small predators running
>around.  Particularly the really fast ones.

They were?  And smaller dinosaurs were likewise grabbed?  Monitor 
lizards?  Wolves regularly take smaller animals as well as large ones, 
and wolves are real pack hunters.  
 
>> Assuming these things, they presumably did what other small,
>> not-very-bright predators did (and do) -- they hunted alone and ate
>> things smaller than they were (large claws notwithstanding).  
>
>Kinda makes the claws pointless, wouldn't you say?  

Not at all.  We have a fossilized feeding event that tells us a lot 
about this (see above).

>What is is that you
>have against a precocial pack predator?  

I have this thing against wild speculation employing a legion of 
mutually dependent, rather forced rationales.    Dinosaurs are 
interesting enough without shoehorning them into the pelts of mammals.

>>Hunting animals larger than you requires both intelligence and 
sophisticated
>>hunting strategies.
>
>Yes, now.  We have no idea whether or not that's a law applicable to 
all
>types of life.  And why dont' pirahnas have any problems, eh?  The 
force
>of numbers strategy does work; we don't see it now because our modern
>predators are stuck on large brains.  Dinos might have made use of it 
to
>good effect.

And so Pirahna joined microbes, sharks, birds and ants in the group of 
animals instructing us about terrestrial pack predation.
 
>> "Other options" should not include basically describing an animal
>> starting with a tabula rosa because it has large claws on its hind 
legs.
>
>It's not.  It also includes analogues to modern predators (other than
>cats and dogs, btw) and fossil finds.

Which modern predators are these?  Which fossil finds? 

>>an animal that sort of cooperates without cooperating, 
>
>Which is done so often in modern animals (most especially non-mammals)
>it's truly staggering.

Example?  Let's stay with terrestrial vertebrates, please.

>>incidentally adopting (systematically!) an incredibly
>>elaborate strategy-that's-not-a-strategy.

>Incredibly elaborate? 
>This is *not*, by any stretch of the imagination, an elaborate 
strategy.

See above for why it is.

Larry

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