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Re: A good day for tyrannosaurs



--- On Tue, 10/6/09, Dann Pigdon <dannj@alphalink.com.au> wrote:

> From: Dann Pigdon <dannj@alphalink.com.au>
> Subject: Re: A good day for tyrannosaurs
> To: dinosaur@usc.edu
> Date: Tuesday, October 6, 2009, 3:58 PM
> On Wed, Oct 7th, 2009 at 9:33 AM,
> Augusto Haro <augustoharo@gmail.com>
> wrote:
> 
> > 2009/10/6 Dann Pigdon <dannj@alphalink.com.au>:
> > >
> > > It makes you wonder, though, how the
> smaller-bodied tyrannosaur species managed to 
> compete
> > > against the juveniles of the larger forms (where
> they were contemporaneous).
> > 
> > I suppose the chicks of larger taxa would have it
> worst in such a
> > competition, unless they were helped by their parents
> and then
> > consumed what the parents hunted, and not the
> tyrannosaurids of their
> > same size.
> 
> Growth rates seem to indicate that a 15-year-old
> Tyrannosaurus would have been about the same 
> size as an adult Alioramus. Of course the two lived at
> different times and in different places, but if 
> Alioramus had roughly the same size and build as
> Nanotyrannus (assuming Nano to be a distinct 
> species), then adult Nanos would have had to deal with
> equivalent sized sub-adult Tyrannosaurus 
> with *fifteen years* of hunting experience.
> 

And how many years hunting experience would an adult Alioramus have?
An Alioramus like tyrannosaur could probably get along with less food, as that 
juvenile T rex will need to eat a lot to be able to grow as quickly as they did 
into an adult.
Or is it possible there is some sort of Bi-stability in T-rex development, if 
they don't get enough food as a juvenile, their growth is stunted, and they end 
up looking like "Nano Tyrannus" as an adult?
Could Nano-tyrannus be a neotenic offshoot of T rex?


Someone else here thought it would be harder on the juvenile T rex rather than 
the small adult Tyrannosaurs (unless the juveniles were accompanied by large T 
rexs in family groups), as the small adults could begin reproducing much 
sooner, and had lower food requirements.
This could be offset in the T rex juvy, by concentrating on getting bigger 
while the small adults concentrated on procreating.
The juvy T rex would spend only a year or two at a size comparable to an 
Alioramus, and after that could probably bully other dinosaurs away from kills, 
and hunt larger prey, and I'd guess once a T rex reached adult hood, it would 
live a relatively long time, at the very least it would have no predators to 
worry about.
Delay reproduction, but ultimately have a longer reproductive period?