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Nocturnal crocs?



As many good people of this list may know, I am investigating the
possibility that relaxation on mammal size constraints toward the very end
of the Cretaceous, brought them over the dinosaur nest/juvenile predation
threshold.  One of the many criticisms leveled at this hypothesis is the
following: if mammals were such a problem for non-concealing dinos, why
didn't they take out non-concealing crocs as well?  A prediction for this
hypothesis is that there should be some critical  difference between these
archosauran clades.  It seems likely that most dinos were diurnal
(see HP Rowe's paper at _Palaeontologia Electronica_ Vol 3, Issue 1).  It
seems likely that most/many mammals were nocturnal.  Small jackals today
cannot approach ostrich nests in the day time but have no trouble at
night.  But what about crocs.  A prediction of this hypothesis would be
that most/all crocs making it through the Cretaceous would be nocturnal
(i.e., they survived because they could defend their nests at
night).  Paul Willis seemed to feel that no Cenozoic crocs possessed
sclerotic rings (a structure linked by Mickey and others to the diurnal
habit).  I searched for
about three days and could find none.  But I did find this from Underwood
writing in _Biology of the Reptilia Vol 2.  "It may be significant that
the only (crocodilians) that survived the Cretaceous were nocturnal."  So,
I just wanted to see if this agreed with what this esteemed body
knows; and, if so, whether it would be considered a nice piece of
supporting evidence.