[Taxacom] "Masteria mystery" solved?

[Kenneth Kinman]

Hi Michael,             
        I think I've solved a lot of the mystery surrounding the
Masteria disjunction.  And thankfully, I didn't need either
panbiogeography or terranes floating long distances east and west across
the Pacific.   

       I looked beyond subfamily Masteriinae to other subfamilies of
Dipluridae, and the distribution of Ischnothele jumped out at me
(neotropics plus one species in India).  Euagrus is somewhat similar,
but involved South Africa instead of India.   

       This pretty clearly points to vicariance (during the Mesozoic)
centered far to the south (in the area of Antarctica), and of course any
intermediate species still in the southern polar region would have
eventually gone extinct (from the cold in particular).  

      So subsequent dispersal of Masteria (by rafting, ballooning, or
whatever) would have been over shorter distances, perhaps the longest
being east to Fiji.  This genus is clearly a fairly good island-hopper
(in both the Pacific and Caribbean).  On the other hand, genus
Ischnothele didn't need to island-hop, but simply rode on India as it
travelled north to Asia.  

     Therefore, I predict that Masteria will be found on other islands
in the Pacific, perhaps even Borneo.  However, diplurid spiders seem to
have had little luck invading very much of Eurasia beyond the area
around India, so competitive exclusion by other mygalomorphs could be a
factor (perhaps even in Borneo). 
            --------Ken Kinman