Re: ... vs energy deficient gigantothermy (boo hiss)

["Tim Williams" <twilliams_alpha@hotmail.com>]

> - I've forgotten whether *Steropodon* or *Kollikodon* is estimated at 1 m
> (the respective other was more normal platypus size, AFAIK), but have any
> others turned up from Cretaceous Australia?
> - Has the 1-m-estimate turned out to be wrong anyway?


I think 1m long is excessive for _Steropodon_ - unless it had a very long 
tail.   I've seen an estimated head-to-tail length of 35cm quoted for this 
animal, which puts it close to the modern platypus.  This appears to be at 
the lower end of estimated body lengths.

It is extremely difficult to confidently estimate size (whether it be weight 
or length) based on isolated jaws.  The jaws and teeth described for 
_Steropodon_ (and _Kollikodon_) are certainly larger than the majority of 
other Mesozoic mammals similarly described from jaws and teeth.

_Steropodon_ and _Kollikodon_ may not be the only Cretaceous monotremes 
named from Australia.  Originally thought to be a pantothere, _Teinolophos_ 
may be a third genus of monotreme from EK southern Australia.  
_Teinolophos_'s jaws and teeth are much *smaller* than those of the other 
two.

_Ausktribosphenos_ (which is known from at least seven jawbones, last count) 
is probably a eutherian - perhaps an early erinaceimorph ("proto-hedgehog").


Tim


------------------------------------------------------------

Timothy J. Williams

USDA/ARS Researcher
Agronomy Hall
Iowa State University
Ames IA 50014

Phone: 515 294 9233
Fax:   515 294 3163

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