SKELETAL VARIATION IN T.REX

["D.W.Naish" <dwn194@soton.ac.uk>]

Just had to say this following Holtz' comments on differentiation amongst     
T. rex and how Bakker thinks there might be two different species (he calls the
other one T. 'x').
We've become 'lumpers', and put fossils that look similar enough in the same
species. Likewise with extant species. Obviously this makes sense when we can't
be sure of how much variation is required between individuals before they are
unable to interbreed, especially amongst extinct species. But dinosaur 
skeletons probably represent more species than we realise because, in life,
species dam near identical in osteology differ genetically, behaviourally and
visually. Enough to be different species. Someone (I think it was Molnar) did
a study of the skeletons of recent lizards and kangaroos and found that, by
their skeletons alone, species we consider distinct when alive would not be
considered so if only their skeletons were looked at. 
This factor is a theoretical 'up' to the numbers of dinosaur species, thus the
number of dinosaur species is even more an under-estimate than thought.

"...the Empire will compensate you fully if he doesn't survive... Put him in!"
 - - Darth Vadar, The Empire Strikes Back

DARREN NAISH