_Saurexallopus_

["Jerry D. Harris" <102354.2222@compuserve.com>]

Message text written by INTERNET:smithjb@sas.upenn.edu

>>_Saurexallopus_ is a Maastrichtian-aged ichnogenus originally 
described in ?1995 by Jerry Harris and some of his/my crazy friends.  
I am not sure about the spelling, but it is close. <<

        'Twas '96, and you spelled it correctly!  Lest list members forget,
ichnotaxa are quite distinct from body fossil taxa, so there is no animal
called _Saurexallopus_...just funky, 4-toed theropod footprints!  People
are bound to want ther refs, so here they are:

Harris, J.D., Johnson, K.R., Hicks, J., and Tauxe, L.  1996.  Four-toed
theropod footprints and a paleomagnetic age from the Whetstone Falls Member
of the Harebell Formation (Upper Cretaceous:  Maastrichtian), northwestern
Wyoming.  _Cretaceous Research_ 17:  381-401.

and

Harris, J.D.  1997.  Four-toed theropod footprints and a paleomagnetic age
from the Whetstone Falls Member of the Harebell Formation (Upper
Cretaceous:  Maastrichtian), northwestern Wyoming:  a correction. 
_Cretaceous Research_ 18:  139.

The latter is just a name correction -- I'd originally called the prints
_Exallopus_, but that turned out to have been used for a worm.  (Who'd've
thought a worm would have a name meaning "different foot?!?")

>>I recently was part of a
team (1996) that described essentially the same morphotype from the 
Maastrichtian-aged Lance Formation (the formation where the first _T.rex_
was
found) of eastern Wyoming.  We are currently writing it up, but it is one
bizzar track.  I am talking only about the Lance examples here, but it
looks 
kind of like a "theropod" track, except that the toes are very long and 
narrow.  The digital pads are not sub-circular or such as
they often are in "Theropod" ichnites, but are elongated more along the
axes
of the toes.<<

        In my original description, the prints I had to work with weren't
nicely enough preserved to show the digital pads (properly, digital nodes),
so this is news to me!  Makes sense, though!

>>There is a very odd hallux that is also very long and 
thin.  It is essentially a quadrupedal ichnite, rather than a tridactyl 
track with a small hallux impression.<<

        Before anyone else jumps in confused, methinks Josh typoed here --
that should be "tetradactyl," not "quadrupedal."  The tracks, AFAICT, are
from a complete biped.

>>Very very strange critter.  We 
have nothing in the Lance record that I know of that could be the 
trackmaker for this little guy.<<

        Or anywhere else, for that matter!  There isn't even a good
dinosaur clade for which good foot material is preserved which could have
made the tracks...

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                     Jerry D. Harris
                 Fossil Preparation Lab
          New Mexico Museum of Natural History
                   1801 Mountain Rd NW
               Albuquerque  NM  87104-1375
                 Phone:  (505) 899-2809
                  Fax:  (505) 841-2866
               102354.2222@compuserve.com