An Unusual Dinosaur Coprolite from the Campanian Aguja Formation, Texas
N. L. Baghai-Riding1 and J. N. Dibenedetto2
1Department of Biological Sciences, Delta State University, Cleveland, MS
2Department of Geology, New Mexico Institute of Mining Technology, Socorro, NM
The Aguja Formation (Campanian) rivals many other Upper Cretaceous localities with regards to the diversity of cranial and postcranial elements of dinosaur remains, early mammals and palynomorphs. Recently a large, globular reptilian multi-tier coprolite (15 cm in length, 9 cm in width and 12 cm in height) of an unknown origin, was collected from the upper shale member of the Aguja Formation in Big Bend National Park, Brewster County, Texas. This rare and unusual find provides for the first evaluation of a large coprolite of this kind from the southwestern United States. The coprolite consists of at least ten individual somewhat cylindrical or tubular, anisopolar units that curve into half-moon shapes. Organic inclusions include inner and outer bark tissue, conifer wood fragments, amber resin and pollen grains from assorted angiosperms. Inorganic inclusions consist of sand grains, manganese oxide, and secondary infillings of pyrite, fibrous-like chalcedony, iron-stained carbonate and white calcite. The size and structure and contents indicate that this coprolite was presumably deposited by an herbivorous dinosaur.
AAPG Search and Discovery Article #90901©2001 GCAGS, Annual Meeting, Shreveport, Louisiana