We are very grateful to the Permian Research Institute, Boise State University, for its support in completing this project. We are thankful to C. Spinosa for improving the English of the text. This project was partially funded by NSF grants (grant # EAR 0106796, EAR- 0106796, EAR-ITR 0218799, and EAR 0312392) and the Russian Foundation of the Fundamental Investigations (RFFI No. 03-05-64303). All of these sources of funds are gratefully acknowledged. We greatly appreciate the suggestions of E. Kulagina from the Geological Institute of the RAS, Ufa, Bashkortostan and J. Groves from the University of Northern Iowa on the foraminiferal taxonomy. We also thank the two anonymous reviewers for their incisive and insightful critiques that significantly improved this paper.