[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Re: a little background



Dear Dinosaurs,

> Dinosaurian ecologies already look like they have a suspiciously high
> proportion of large herbivores; they also look like getting to adult
> size as a large herbivore was really bad odds.  Since we don't know when
> in the life cycle the primary mortality occurred, there's a lot we can't
> infer about predation, but the indication seems to be that smaller
> herbivores -- and that includes things about to about 500 kg!! -- were
> in marginal, speciality niches, despite being at lower risk of
> predation, anywhere except really low-energy (arid or arctic/antarctic)
> environments.

Situation where relatively big and slow "megaherbivores" dominate the
ecosystem is probably normal. Only during the last 40.000 years it
changed, because of megafauna extinction and hunting and poaching of few
remaining species. Even national parks are not much different, because
large herbivores are generally culled when they start damage to
vegetation.

But you touched the interesting ecological feature. If large dinosaurs had
indeed large brood size and frequent broods, then their young, produced
from food resources unavialable to small animals could well outcompete the
small species. This would establish even bigger domination of largest
dinosaurs.

Interesting would be the ecology of such species, if young herbivores were
not fed by adults. Growing to adult size, the dinosaur would pass several
different ecological niches. Strange world.

J.