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Re: Mesozoic forests (was predator relationships)



Gigi Babcock or Ralph Miller III wrote:
> 
>  Chris Campbell wrote:
>  > <snip>
>  >  Some of your old growth forest is quite clear of underbrush
>  > and low limbs, so a _T._rex_ might have done fine there.
> 
>  Dann Pigdon <dannj@alphalink.com.au> wrote:
> > This would have been especially true in the Mesozoic, with all of
> > those large herbivores around. I always thought that the trees
> > featured in many dino reconstructions were giant tree ferns,
> > until I happened to notice the growth pattern at the top of
> > a live araucarian and it suddenly hit me: those pictures were
> > probably of araucarians that had been "pruned" by sauropods. I
> > suspect that if tyrannosaurs followed large herds of herbivores
> > around, that the prey themselves may have cleared the forest
> > areas of low lying branches.
> 
> Actually, if we're on the same page (so to speak), you may rather be seeing
> tree ferns in those illustrations.

        Nope they're definitely trees. I'm refering to Brian Franczak's
tarbosaurs and maleevosaur. There is also Greg Pauls
much revised brachiosaur illustration. Could the trunk of a tree
fern support a plant apparently taller than a brachiosaur?
 
> 
> Within the extant Araucariaceae we now have four species:  _Araucaria
> heterophylla_, the Norfolk Island Pine; _Araucaria araucana_, the Monkey
> Puzzle tree from Chile; _Araucaria bidwilli_, the Bunya Bunya Pine of
> Australia; and the recently discovered _Wollemi nobilis_, the Wollemi Pine
> of Australia. 

        Yes, and most of them in my own back yard (continent-wise
that is).

> The "araucarians" you refer to are perhaps the monkey
> puzzles which may form a "lollipop-shaped" array of branches at the top (in
> mature specimens).

        Actually, the trees I noticed had branches all of the way down
the trunk. It was the growth pattern at the top of the tree that
lead me to imagine it without the lower branches, and the image fitted
the trees I'd seen illustrated in several places. I'd imagine
they were one of the Australian species (Norfolks perhaps).

> The leaf types and toxins associated with living gymnosperms (whose
> ancestors made up the dominant terrestrial flora before the advent of
> angiosperms in the mid-Cretaceous) presents a puzzle in itself.  The
> foliage of ferns and of the dawn redwood would seem to be the easiest to
> consume.  That the Mesozoic was populated by an array of vegetarian
> behemoths is testimony to the ability of the dinosaurs to adapt to their
> environment.  What species of megafauna today could subsist on pine
> needles?  And yet, there they are, inside the belly of the _Edmontosaurus_
> mummy.  Amazing!

        I suppose it depends on how common or wide spread the other
species of plants were. Perhaps pines were more common, therefore
show up in coprolites more often.
-- 
____________________________________________________
        Dann Pigdon
        Melbourne, Australia
        http://www.geocities.com/capecanaveral/4459/
        http://www.alphalink.com.au/~dannj
____________________________________________________