Re: Biggest predator? (Fringe topical at best)

["Larry Dunn" <larrydunn@hotmail.com>]

>From: Chris Campbell <sankarah@ou.edu>

>I dunno, that's kinda like wondering what the biggest land predator
>was.  _T-rex_?  _Gigantosaurus_?  Something else?  Who knows?  Maybe 
you
>count _Shonisaurus_, the 50' Icthyosaur, and then there's the 40'+ 
shark
>_Carcharadon megalodon_, then _Kronosaurus_, _Liopleurodon_, perhaps
>_Mososaurus maximus_, and so on.  All of these were truly immense in
>size, but all cap out at somewhere around 40-50' (although _M. maximus_
>probably wouldn't be a true competitor; I believe it's max length was
>something like 35 feet or so).  Yes, _P. catodon_ can reach 20 meters,
>but those individuals are quite rare and we can be sure that our
>specimens of the above mentioned reptiles and fish aren't the largest
>individuals of their respective species.
>
>In answer to your question, _P. catodon_ is definitely among the 
biggest
>predators of all time, but to call it the biggest is like calling _T.
>rex_ the biggest therapod of all time; you can do it, but you may well
>be proven wrong somewhere down the line.

All that aside, successful, practicing vertebrate paleontologists mix 
apples and oranges in this way all the time -- comparing the dimensions 
of animals known only through fossil remains with dimensions of extant 
species.  You could also add that P. catodon may get bigger than 20m 
because we haven't measured every one that's ever lived.  Needless to 
say, we know the giant sperm whale far better than any pliosaur, but 
that doesn't mean we know them well.  We don't.  

We have certain dimensions for extant animals; from a much smaller 
sample, we have certain dimensions for extinct animals.  Comparisons 
*will* be made and admittedly unscientific, "Guinness-like" positions 
*will* be assigned.  It's something we have a strong interest in (why 
else would we do it all the time?), so start getting used to it as you 
will eventually venture forth into your career as a young scientist; 
terribly imprecise and unprofessional though these annoying, 
layman-oriented questions may be, they will be asked.

Thanks to others who offered up possible candidates without pointing to 
the all-too-obvious-anyway man behind the curtain, and especially to 
Dann Pidgon for his helpful reminder of that "new" pliosaur -- it was in 
the back of my head that a possible giant surpassing Kronosaurus had 
been discovered.  This is the only rival to P. catodon that seems at all 
viable (sorry Caitlin -- go to Kansas and find a really big Tylosaur!).

Larry

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