Paper No. 235-2
Presentation Time: 1:15 PM
THE VERTEBRATE BROMALITE RECORD IN THE WESTERN UNITED STATES
The vertebrate fossil bromalite record in the western United States is the most extensive record known and mainly comprises coprolites. The oldest possible coprolites are from the Middle Cambrian of UT. Devonian coprolites are reported but not described. Mississippian coprolites, including Ostracobromus snowyensis, occur in the Bear Gulch Lagerstätte of MT and also in the Fayetteville Shale of OK. Pennsylvanian bromalites are more widespread and abundant in various localities, including the Weber Formation, CO, the Tinajas (e.g., Crassocoprus mcallesteri, Crustacoprus tinajaensis) and Kinney (e. g., Conchobromus kinneyensis) Lagerstätten and Beeman Formation (e.g., Kalocoprus oteroensis, Bibliocoprus beemanensis), NM. Other Pennsylvanian coprolites are in KS (e.g., Hamilton Quarry) and TX (Finis Shale). Early Permian coprolites are locally abundant in redbeds of NM, OK and TX and include diverse ichnotaxa (e.g., Heteropolacopros texaniensis, Hyronocopros amphipola, “Megaheteropolacopros sidmcadamsi,” Dakyronocopros arroyoensis, Alococopros triassicus). Coprolites occur in the Middle Triassic Moenkopi Group in AZ-NM. The Upper Triassic Chinle Group yields abundant coprolites in WY, UT, AZ, NM, CO and TX from Otischalkian, Adamanian, Revueltian and Apachean strata. Ichnotaxa include Dicynodontocopros maximus, Heteropolacopros texaniensis, Alococopros triassicus and Eucoprus cylindratus. Bromalites associated with skeletons of Coelpohysis bauri indicate cannibalism. The Jurassic bromalite record is only a handful of well documented localities: (1) coprolites from the nonmarine Early Jurassic Glen Canyon Group; (2) consumulites and evisceralites from the Middle Jurassic Todilto and Sundance formations; and (3) consumulites, putative coprolites and pseudobromalites from the Upper Jurassic Morrison Formation. Upper Cretaceous and early Tertiary coprolites occur in many bone-bearing formations but have been under-reported in the literature except in the San Juan Basin of NM. The White River Group (Eocene-Oligocene) has the best-studied and most abundant samples of vertebrate coprolites in the Cenozoic. Pleistocene coprolites are significant in southwestern caves, notably in northern AZ, but also UT and NM. Human coprolites are locally common in caves and open air sites.