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PAN PAN PAN, VARANIDS & THEROPODS



Betty, there is no such thing as _Pan pan pan_. _Pan_ is the chimp 
genus: there are two recognised species, _P. troglodytes_ and _P. 
paniscus_. Arguments still rage over whether or not certain chimp 
'subspecies' are worthy of specific status, but that's incidental 
here.

Larry (not a pigeon), forwarded Michael Balsai's comments on 
Cretaceous varanids. Michael wrote..

> Anyway, I believe it is merely a matter of time before _Varanus_ 
> gets broken up into several genera. Many consider the pygmy sized 
> clade from Australia and surrounding islands to be an off shoot 
> evolution from the main branch and I sometimes see them 
> called the "Odatria" group.

Most dino-fans are familiar with the uniformitarianism applied to 
dinosaur taxa by Greg Paul (e.g. sinking multiple tyrannosaurid and 
ornithomimid genera), and an argument he used for his case was the 
morphological disparity seen amongst skulls of extant _Varanus_. 

Members of _Varanus_ do indeed represent highly disparate 
morphotypes, and accordingly a wealth of subgenera have been 
described. However, few of these stand up in cladistic analyses as 
the taxa that group into clades are invariably different from 
traditional subgenera. Two of the Indo-Australian varanid subgenera, 
_Euprepiosaurus_ and _Odatria_ , have recently proved polyphyletic, 
and other subgenera (e.g. _Varanus_) are paraphyletic I think.

If we were to reassign varanids to subgenera (and assuming we wanted 
to keep all our taxa monophyletic), we would end up with a wealth of 
subgenera - I mean 15 or 20 as opposed to 5 or 6. It is therefore 
being advocated at present that division of _Varanus_ into subgenera 
is unwarranted or, at best, unwise.

Unfortunately I do not have the ref for this work with me today: it 
is a 1991 review by Sprackland. As for Cretaceous varanids, I recall 
that one was described in _JVP_ this year/last year: I can't find 
this paper, can anyone give the ref?

"And so, Dr. Beckett finds himself leaping from life to life, putting 
things right which once went wrong, and hoping, each time, that his 
next leap... will be the leap home"

DARREN NAISH
darren.naish@port.ac.uk