From their descriptions it would seem that theses two
species would be fairly easy
to tell apart. But unless you have the two species side by side,
characteristics such as lingual
protuberance and serration size are too close to really be of much use.
I have found that
the easiest way to tell these two species apart is to look for the
twisted crown for G. contortus,
or lack of it for G. aduncus.
A much rarer third species, Galeocerdo eaglesomi
has been reported from the Eocene of NJ.
Authors note: G. contortus has been moved to
the genus Physogaleus. Since G. contortus is still
commonly referred to as a "tiger" I will continue to use the old name.
Left - Galeocerdo contortus, twisted
crown Right -
Galeocerdo aduncus, straight crown
Left - Galeocerdo contortus Right -
Galeocerdo aduncus
Galeocerdo eaglesomi is
restricted to the Eocene and to my knowledge
only a few specimens have been found in New Jersey.
