Geoscience Reference
In-Depth Information
Dens are used by alligators for a variety of reasons, such as keeping their skin
from drying out from sun and heat, maintaining more reliable “indoor” temperat-
uresduringcoldwintersorhotsummers,orprovidingsafetyfromdroughtsorfires.
Most important, though, these burrows serve as a refuge for young, newly hatched
alligators, which are watched closely for more than a year by the ultimate of over-
protective mothers. In my studies on the Georgia barrier islands, I had already ex-
perienced a few tooclose-for-comfort encounters with alligator mothers and babies
near their dens and learned to proceed with extreme caution near them, treating all
such large burrows as if they were loaded guns.
In their evolutionary history, Chinese and American alligators shared a com-
monancestor nottoofarbackinthegeologic past,buttheyalsoconnect toall other
crocodilians, a lineage that extends well into the Jurassic Period. However, despite
thisancientheritage,nocrocodilianburrowshadbeeninterpretedfromthefossilre-
cord. This made the structure in Dave's photo potentially exciting, but not knowing
the age of the rocks in the photo, or even their location, I could not allow myself to
get too enthused about it. Still, I knew that Dave often prospected Cretaceous-age
rocks in Montana and other parts of the western U.S., so I held some hope that he
hadfoundaCretaceousexampleofacrocodilianburrow,andonewithacrocodilian
at the end of it. Such a discovery would have been very pleasing to me, because it
would have linked directly with my Georgia-coast interests in alligator dens, while
also documenting a much deeper history of burrowing behaviors in crocodilians.
MymildcuriosityconcerningwhetherIwasrightornotaboutmycrocodilian-
in-a-bank-burrow hypothesis was addressed later the same day, but in a completely
unexpectedway.ItturnedoutthatIwasbothrightandwrong.Dave'snextmessage
had an intriguing title: “hoping you say 'yes'.” Here are the first three sentences of
text from his note:
