Re: Morrison Sauropods\etc. (long)

[HPB1956@aol.com]

There is quite a diversity of huge (= adult) plant eaters in the Morrisson
Formation with Apatosaurus, Barosaurus, Brachiosaurus, Camarasaurus,
Diplodocus and Haplocanthosaurus compared with todays eco-systems. Every
genus may have filled a different ecological niche to evade direct competiton.

But this is only the tip of the iceberg. There must have been an abundance of
sauropod babies and juveniles. According to Gregory Paul in "Dinosaur Eggs
and Babies" a sauropod could have produced between 500 - 4000 eggs in a
40-year interval.

For us humans to keep population size stable a woman must have about 2.1
children on average. If we take , let's say, an average of about 1000 eggs
per female sauropod for this, this would mean that sauropods needed about 500
times more offspring to keep their numbers stable.

This in turn would mean that there was a huge number of juveniles (with a
very high mortality rate, what a carnage), which contained the real genetic
variety needed for survival of a species. So the total number of adult
animals needed for survival may have been very much lower as in today's
mammals.

But the problem I see is that juveniles of at least six different genera
competed for food and shelter. And that with a basically identically bauplan.
At young age sauropods genera must have been more similarily built than later
as adults. Additionally there were an overlap in size. This means e.g. each
genera reaching at some time of their growth food in a height of two meters.
And this independently of their later adult sizes.

So the real competition was in the kindergarten including theropods bigger
than these youngsters.

Any comments are welcome.

And now cheers from a sunny Germany (time to go swimming)


Heinz Peter Bredow