Geoscience Reference
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chemicalconditions,mineralizationalsocouldhaveacceleratedoncethefeceswere
buried, as more anaerobic bacteria would have joined the mineralization party.
However, a dinosaur coprolite turned to stone is not necessarily the end of its
journey, in which it waits patiently for a well-trained paleontologist to recognize it
for its true fecal nature. Coprolites are among the few dinosaur trace fossils—such
as toothmarks in bones, and gastroliths—that could have been transported before
andafterburial,orreburied.Beforeburial,adinosaurturdcouldhavefallendowna
hillslope,hadpartofitrolledbyadungbeetle,orcarriedsomedistancebyflowing
water. After burial, it could have been exhumed by wind, streams, tides, or waves,
and moved to a new place before getting buried again, or not—in which case it
mighthaveweathered,eroded,andvanishedfromthefossilrecordmillionsofyears
before human consciousness. This also means a dinosaur coprolite, like dinosaur
bones,feasiblycouldbereburiedingeologicallyyoungersediments.Inshort,where
you find a dinosaur coprolite in the field should never be assumed as representing
the same place or time where that dinosaur took a dump.
Given all of these special conditions for preserving dinosaur coprolites, they
understandablyareamongthemostpreciousofdinosaurtracefossils.Theyarealso
amongthemostdifficult toattribute toaspecific dinosaur.Onceacoprolite isiden-
tified,paleontologistsoftenlimitthemselvestosayingitbelongstoacarnivorousor
herbivorous dinosaur based on its contents (bone or plant fragments, respectively).
This is where bigger is better, in that large coprolites are easier to connect to dino-
saurs big enough to have made them, whereas smaller ones could have been made
by a wide range of small dinosaurs. Dinosaur body and trace fossils also help, in
which paleontologists can play the much-cherished game of “match the defecator.”
Of dinosaur coprolites identified thus far, the best understood ones are attrib-
uted to the Late Cretaceous hadrosaur
Maiasaura
of Montana. Some of these cop-
rolites are quite large; although most are broken into smaller pieces, some suggest
original volumes of about 7 liters (1.8 gallons). (For perspective, a regulation U.S.
basketball is about 8.5 liters.) Other large coprolites are credited to Late Cretaceous
