Small, oblong, limonitized coprolites (<0.5 mm) containing macerated t
errestrial plant debris have been recovered in Westphalian and Stephan
ian (Upper Pennsylvanian) gray to black shales that were deposited in
dysoxic outer-shelf marine environments. The internal structure and ex
ternal surfaces of the coprolites are unlike those of vertebrate copro
lites and unlike ejecta recovered in stratigraphically adjacent anoxic
sediments. Stratigraphically adjacent oxygenated sediments have been
homogenized by numerous kinds of mobile benthic invertebrates, whose a
ctivities have probably destroyed any trace of plant-bearing coprolite
s in the more nearshore environments. Coprolites of terrestrial origin
that contain plant debris are considered to have been generally too l
oosely consolidated to survive long-distance transport from lens to pe
rhaps several hundred kilometers from land. Thus, the coprolites in th
is report appear to represent a feeding pattern, by one or more kinds
of marine macroinvertebrates, on drifted land-plant debris that sank i
nto offshore marine environments. Distribution of such plant destructi
on represents a previously undocumented taphonomic pathway, demonstrat
ing an unsuspected plant-animal interaction for terrestrial macroscopi
c plant debris in Upper Paleozoic marine environments.