1. Arambourg, C. (1959). Vertébrés continentaux du Miocène supérieur de l’Afrique du Nord. Paléontologie Mémoires, 4, 1–161.
2. Boaz, N. T., Howell, F. C., & McCrossin, M. L. (1982). Faunal age of the Usno, Shungura B and Hadar Formations, Ethiopia. Nature, 300, 633–635.
3. Bobe, R., Behrensmeyer, A. K., & Chapman, R. E. (2002). Faunal change, environmental variability and late Pliocene hominin evolution. Journal of Human Evolution, 42, 475–497.
4. Cerling, T. E. (1992). Development of grasslands and savannas in East Africa during the Neogene. Palaeogeography, Palaeoclimatology, Palaeoecology, 97, 241–247.
5. Churcher, C. S. (1978). Giraffidae. In V. J. Maglio & H. B. S. Cooke (Eds.), Evolution of African Mammals (pp. 509–535). Princeton: Princeton University Press.