Geoscience Reference
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• Did it come from rocks formed in a continental environment, such as a
former soil, river, or lake?
• Were other dinosaur body and trace fossils in the same rocks?
• Does it fall in the right size range for known dinosaur coprolites?
• Does it contain any body fossils of what might have been digested, such as
plant or bone fragments?
Only when you have answered this checklist with “yes” for every item should
you take your rock to a professional scientist. Otherwise, she will tell you wearily
that wrongly identified “coprolites” are the bane of her existence, rivaled only
by wrongly identified “meteorites” and “gold.” In this respect, the most basic
questions—dealing with age, environment, co-occurrence with other dinosaur
fossils—areveryimportant.Forinstance,ifyoufoundthisrockinCincinnati,Ohio,
Iwouldinstantlytellyouitisnotadinosaurcoprolite.Cincinnati'sagreatcitywith
a lot going for it, but it has the wrong age rocks (Ordovician Period, 450 milli-
on years old) and wrong rocks (shallow marine limestones and shales), and hence
no dinosaur fossils. As a result, its civic boosters should never add “dinosaur cop-
rolites” to its list of local natural wonders, which would remain true even if you
crossed the Ohio River and went into Kentucky.
Of these criteria, by far the most important one is that it contains body fossils
of whatever the dinosaur ate. A suspected coprolite may look like fossil crap, feel
like fossil crap, and taste like fossil crap, but does not qualify as fossil crap unless
it holds fossil food. There had better be plant tissues, spores, seeds or pollen, bits of
bone, insect or crustacean parts, or other bodily remains for a lumpy chunk of rock
to qualify as a genuine, bona-fide coprolite.
The least important criterion applied to coprolites is size, and that is because
of its variability. Dinosaur dung may have been as big as footballs (American or
Australian rules), or it could have been as small as chocolate-covered raisins. Co-
prolite size would have depended on: the age and size of the defecating dinosaur;
its health; time of the year; or what happened to the dung after it emerged. Even the
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