Acarina, pycnogonids, Permian ticks?

[Ken Kinman]

     If Acarina are polyphyletic (i.e., the two lineages are not sister
groups) as Van der Hammen's research indicates, the parasitiform lineage may
be a little younger than the acariform.  However, I would still expect to
see parasitiforms by the Upper Devonian.
      Silurian mites or any Silurian arachnids are something to look forward
to.  Although scorpions are known from the Silurian, they are not arachnids.
  Class Scorpionea (incl. eurypterids) goes back at least to the early
Ordovician, so one can't completely rule out the possibility of Ordovician
arachnids (but I wouldn't hold my breath).
      Then there is Class Pycnogonea (sea spiders), which Bonnie Blain
believes are actually arachnids (supposedly related to mites, but I'm not
sure which groups of mites she relates them to).  Have any of her papers on
the pycnogonid-acarina relationship appeared yet?   Unless her evidence is
particularly strong, I assume such a proposed relationship will be
controversial.
     I wrote to Hans Klompen last week about the "hairy" New Jersey tick
(Carios).  Some of the news reports were misleading, indicating that Klompen
said ticks originated in South America.  Actually he said the genus Carios
probably originated in South America, and that the ticks as a group probably
originated in or near Australia.
     That may be true, but I disagree with Klompen that ticks probably arose
in the mid-Mesozoic (Jurassic?).  I think that they will definitely be found
in the Triassic, probably in the Permian, and an Upper Carboniferous tick
wouldn't shock me (although again, I wouldn't hold my breath on a
pre-Permian origin).
     Therefore I think that there were plenty of ticks in North America
during the Cretaceous, and Klompen's hypothesis that the New Jersey tick
hitched a ride on a seabird from South America is rather far-fetched.  The
genus Carios more likely existed in New Jersey, feasting on New Jersey birds
of some kind.  So I wouldn't be surprised to find more _Carios_ ticks in the
Cretaceous of New Jersey.  In my opinion, we should be on the lookout for
ticks throughout the entire Mesozoic of North America.
                  ---Cheers,  Ken Kinman
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