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

Re: Size of *Neoceratodus africanus* and/or *N. tuberculatus*

I might suggest that the young did indeed focus on fish for their main diet but 
the largest adults turned into greater opportunists over time. If great 
predators such as this were seasonal hunters and knew when certain lakes dried 
up where and when then suddenly great size is a huge advantage. The giant can 
stay and eat the easy to catch fish leaving the smaller Spinosaurs hungry. 
Sometimes if a lake isn't completely dry but merely shallow or if there is a 
bottle neck in a river then the largest Spinosaurs, still holding sway the way 
the biggest meanest bears take the best fishing spots, then their giant well 
formed fishing jaws would still come in handy for opportunistic fishing. 

During extreme food shortages only the very biggest live. 

Drew Simpson

--- On Sun, 3/29/09, Raptorial Talon <raptorialtalon@gmail.com> wrote:

> From: Raptorial Talon <raptorialtalon@gmail.com>
> Subject: Re: Size of *Neoceratodus africanus* and/or *N. tuberculatus*
> To: tijawi@yahoo.com
> Cc: dinosaur@usc.edu
> Date: Sunday, March 29, 2009, 4:33 PM
> "I'm only arguing against the hypothesis that
> spinosaurids were
> specialized piscivores, or even that fish (including giant
> lungfish)
> were even a major part of their diet."
> I suppose the bottom line is, why were animals as large as
> spinosaurs
> possessed of such an unusual head/neck morphology? Pretty
> much every
> other group of large theropods has robust skulls adapted to
> either
> hacking/slashing or gouging/crushing - features suitable
> for big
> predators taking big prey. Yet spinosaurs are virtually
> antithetical
> to this arrangement, being large to very large predators
> that are very
> ill-suited to taking large prey.
> I'm not yet convinced that a generic diet of smaller
> animals
> (dinosaurs, crocs, lizards, whatever) is sufficient to
> explain the
> extreme development of the snout/neck traits seen in
> spinosaurs.
> Plenty of other medium-smallish to medium-largish theropods
> must have
> had broadly similar diets, yet never specialized in that
> way. And of
> course they don't seem to have reached such stupendous
> proportions on
> those diets, either. I would strongly suspect that, at the
> very least,
> the taking of aquatic prey was an important driver in
> spinosaur
> evolution, even if other prey types continued to be
> imporant food
> sources.