crocs and hadrosaurs (was science proect)

["Cunningham, Betty" <Cunningham@sega.com>]

Steve Throop wrote:

>Suppose a giant croc was in ambush at the water's edge when he heard a
>three-ton duckbill running toward him.  Wouldn't discretion be the
>better part of valor?  After all, a croc killed by accident would still
>be dead.

If I was the croc, I'd be much more worried about what was chasing the   
duckbill.  It's just as big and has more teeth besides.  And would   
probably just as happy eating croc (tastes like chicken) as dinosaur.   
 Actually crocs near the shore would more likely be spotted by the taller   
T rex as they lose their camoflage abilities when viewed from above (like   
in croc pits at zoos), so the crocs would probably be leary of coming   
within reach of a taller advisary.  This would seem to also work against   
the crocs and for duckbills-except with the newer quadrepedal posture of   
duckbills (and not the old bipedal one) their heads would be much closer   
to the ground, especially while feeding, than T rex's and so the crocs   
could still depend on camouflage for stealth.

>In movies, crocs swim long distances toward human swimmers.  Is that
>accurate?  GS Paul said, "Reptiles cannot aerobically sustain speeds
>over 1-2 km/h no matter how toasty warm they may be."  If they're that
>slow on land, it sounds as if a croc in the water would be pretty slow
>once its anaerobic energy ran out.

crocs and alligators and caimans (did I leave any out?) are all very   
efficient in the water.  They are all built to swim with minimum energy   
out-put; the tail does most of the work while the body remains fairly   
stable and the legs hardly move at all.   Most of the modern crocs'   
hunting technic is merely hanging out unmoving in the water till it can   
sneak up on somebody else and grab it, pull it under and hold it under   
long enough to drown it. I don't have statistics on any croc metabolism,   
but I'm willing to vernture that there is less energy spent cutting   
through water while bouyant, than in getting out of the water to sun.

>At least some duckbill genera inhabited conspicuous nesting grounds as
>their young grew.  These were apparently not in swamps, but doesn't this
>imply that they had methods of standing their ground against predators?

Maiasaurs nested on lakeshores-not strictly a swamp, but pretty similar   
conditions. Sort of like how modern flamingoes and storks nest in the   
mudflats of the African savannahs after the rains.  Both of these can fly   
to protect the adults, but they rely on the water to isolate and protect   
the young.

>Don't crows drive hawks and owls from an area by harassment?  Couldn't
>duckbills  also have used commotion and tooting to encourage big crocs
>to relocate?

probably not crocs- modern types hunt by camouflaging themselves and   
waiting for prey to come by.  In all likely hood, it's only the first   
duckbill which would be taken unawares, and the rest of the herd would be   
alerted by the struggle.  Since the croc kills by strangulation and   
drowning, the duckbill may not be able to honk at all-no matter how big   
it's crest is. (or conversly-maybe that's what the dang things are   
for-doesn't seem likely since there would be no muscle forcing the air   
out)

>Have horses and goats been known to kill snakes on sight?  Humans, dogs,
>and cats seem to have that impulse.

having been exposed to all of the above, I'd say cats and dogs mess with   
snakes because they have a hunting instinct to kill little   
things-salamanders or lizards would get exactly the same treatment.   
 Horses don't like things they can't see which make unusual noise (like   
rattling rattlesnakes) but will ignore gartersnakes in their stalls   
simply because they don't see them.  Goats just get bored unless the   
snake does something to interest them.  People are just plain ol' dumb to   
kill a snake-means they were raised wrong

>If duckbills instinctively stamped on small crocs, that would eventually   
>reduce the chances of meeting a big, hungry one.

or any more duckbills-whose babies LOOK an AWFUL lot like BABY CROCS.

on another note-would sea-going crocodiles hunt similarily to modern   
crocs by using stealth?  What did the sea-going crocs eat?
I haven't got any info at all on their feeding habits or probable niche.

 -Betty