Re: dem bones

[NEIL CLARK <NCLARK@museum.gla.ac.uk>]

Blaise wrote:-
> I am not (conscientiously) trying to sound like an idiot, nor fan 
the 
> flames of an anatomical jihad, but with today's advanced forensic 
> techniques, why is it so difficult to determine how the basic skeleton of 
> a dinosaur fit together.  I can see the difficulty with something like 
> stego's plates or tail spikes, but with something as essential as ribs or 
> a leg, I am lost. 

It is not just the dinosaurs that have the problem of being 
reassembled wrongly/correctly, early hominids are a problem too.  If 
you assemble the ribs one way, you get a tear-drop chimp-like chest, 
and if you assemble them another way, you get a barrel-shaped modern 
chest.  This all hinges on the size and shape of the cartilagenous 
sternum that is not preserved.  If, with all the forensic techniques 
availible, we can't reconstruct early hominids with 100 per cent
certainty, dinosaurs will be out of the question.  We can only refine
the best-fit model based on current theories.  The big problem is 
trying to reconstruct using the hypothetical missing pieces of the 
jigsaw.  Some structures' shapes can be inferred from characteristic 
markings on bones, but even the inference may be wrong.

Anyone else with thoughts on this?

Neil

BTW has anyone apart from John Rafferty looked at my sketch of the 
dinosaur? bone that I have?  It is 3.7cm long and may be 
sauropod/theropod/croc/pterosaur.  I would like to know 
of any reference that I can use to distinguish caudal vertebrae.