The Laborcita Formation of the Sacramento Mountains, N. Mex., overlies the Holder Formation (Upper Pennsylvanian) and underlies the Abo Formation (Lower Permian); it is believed to represent continuous deposition from the top of the Holder to the base of the Abo. Megafaunal evidence is inconclusive regarding the age of the unit; preliminary study of fusulinid zones suggests a Pennsylvanian-Permian boundary 90 feet above the base of the formation (Otte, 1959). Restudy of the fusulinid fauna permits identification of these principal species: Dunbarinella americana, Schwagerina campensis, S. emaciata, Triticites creekensis, T. ventricosus. Consideration of published ranges of these species in conjunction with less populous elements of the fauna demonstrates that the Laborcita is wholly Wolfcampian (Bursum) in age.

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