Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Oligocene mammals from Ethiopia and faunal exchange between Afro-Arabia and Eurasia


Afro-Arabian mammalian communities underwent a marked transition near the Oligocene/Miocene boundary at approximately 24 million years (Myr) ago. Although it is well documented that the endemic paenungulate taxa were replaced by migrants from the Northern Hemisphere, the timing and evolutionary dynamics of this transition have long been a mystery because faunas from about 32 to 24 Myr ago are largely unknown1. Here we report a late Oligocene fossil assemblage from Ethiopia, which constrains the migration to postdate 27 Myr ago, and yields new insight into the indigenous faunal dynamics that preceded this event. The fauna is composed of large paenungulate herbivores and reveals not only which earlier taxa persisted into the late Oligocene epoch but also demonstrates that one group, the Proboscidea, underwent a marked diversification. When Eurasian immigrants entered Afro-Arabia, a pattern of winners and losers among the endemics emerged: less diverse taxa such as arsinoitheres became extinct, moderately species-rich groups such as hyracoids continued into the Miocene with reduced diversity, whereas the proboscideans successfully carried their adaptive radiation out of Afro-Arabia and across the world.

This is a preview of subscription content, access via your institution

Relevant articles

Open Access articles citing this article.

Access options

Rent or buy this article

Prices vary by article type



Prices may be subject to local taxes which are calculated during checkout

Figure 1: Map of Chilga and surrounding area containing the fossil localities.
Figure 2: The Chilga section preserves volcanics and fluvial sediments.
Figure 3: Fossils representing paenungulate taxa from Chilga.


  1. Maglio, V. J. in Evolution of African Mammals (eds Maglio, V. J. & Cooke, H. B. S.) 603–619 (Harvard Univ. Press, Cambridge, MA, 1978)

    Book  Google Scholar 

  2. Murdock, T. G. The Chilga Lignite Deposits. US Technical Project in Ethiopia (Mineral Investigation Memorandum no. 19, Ministry of Mines, Addis Ababa, 1944)

    Google Scholar 

  3. Yemane, K., Bonnefille, R. & Faure, H. Palaeoclimatic and tectonic implications of Neogene microflora from the Northwestern Ethiopian highlands. Nature 318, 653–656 (1985)

    Article  ADS  Google Scholar 

  4. Yemane, K., Robert, C. & Bonnefille, R. Pollen and clay mineral assemblages of a late Miocene lacustrine sequence from the northwestern Ethiopian highlands. Palaeogeogr. Palaeoclimatol. Palaeoecol. 60, 123–141 (1987)

    Article  Google Scholar 

  5. Yemane, K., Taieb, M. & Faure, H. Limnogeologic studies on an intertrappean continental deposit from the northern Ethiopian Plateau (37°03′ E, 12°25′ N). J. Afr. Earth Sci. 6, 91–101 (1987)

    ADS  Google Scholar 

  6. Spell, T. L., McDougall, I. & Doulgeris, A. P. Cerro Toledo rhyolite, Jemez volcanic field, New Mexico: 40Ar/39Ar geochronology of eruptions between two caldera-forming events. Geol. Soc. Am. Bull. 108, 1549–1566 (1996)

    Article  ADS  Google Scholar 

  7. Feseha, M. Sequence Stratigraphy, Petrography, and Geochronology of the Chilga Rift Basin Sediments, Northwest Ethiopia Thesis, Univ. Texas (2001)

    Google Scholar 

  8. Cande, S. C. & Kent, D. V. Revised calibration of the geomagnetic polarity timescale for the Late Cretaceous and Cenozoic. J. Geophys. Res. 100, 6093–6095 (1995)

    Article  ADS  Google Scholar 

  9. Hofmann, C. et al. Timing of the Ethiopian flood basalt event and implications for plume birth and global change. Nature 389, 838–841 (1997)

    Article  ADS  CAS  Google Scholar 

  10. Rochette, P. et al. Magnetostratigraphy and timing of the Oligocene Ethiopian traps. Earth Planet. Sci. Lett. 164, 497–510 (1998)

    Article  ADS  CAS  Google Scholar 

  11. Ukstins, I. A. et al. Matching conjugate volcanic rifted margins: 40Ar/39Ar chronostratigraphy of pre- and syn-rift bimodal flood volcanism in Ethiopia and Yemen. Earth Planet. Sci. Lett. 198, 289–306 (2002)

    Article  ADS  CAS  Google Scholar 

  12. Baker, J., Snee, L. & Menzies, M. A brief Oligocene period of flood volcanism in Yemen: implications for the duration and rate of continental flood volcanism at the AfroArabian triple junction. Earth Planet. Sci. Lett. 138, 39–55 (1996)

    Article  ADS  CAS  Google Scholar 

  13. Andrews, C. W. A Descriptive Catalogue of the Tertiary Vertebrata of the Fayum, Egypt 1–324 (British Museum of Natural History, London, 1906)

    Google Scholar 

  14. Tanner, L. G. in Evolution of African Mammals (eds Maglio, V. J. & Cooke, H. B. S.) 279–283 (Harvard Univ. Press, Cambridge, Massachusetts, 1978)

    Google Scholar 

  15. Wight, A. W. R. in The Geology of Libya Vol. 1 (eds Salem, M. J. & Busrewil, M. T.) 309–325 (Academic, London, 1980)

    Google Scholar 

  16. Pickford, M. Premiere découverte d'une faune mammalienne terrestre paléogene d'Afrique sub-saharienne. Comptes Rendus l'Acad. Sci. Paris Série II 19, 1205–1209 (1986)

    Google Scholar 

  17. Thomas, H. et al. in Fossil Vertebrates of Arabia (eds Whybrow, P. J. & Hill, A.) 430–442 (Yale Univ. Press, New Haven, 1999)

    Google Scholar 

  18. Rasmussen, D. T. & Simons, E. L. New Oligocene hyracoids from Egypt. J. Vert. Paleontol. 8, 67–83 (1988)

    Article  Google Scholar 

  19. Rasmussen, D. T. in The Evolution of Perissodactyls (eds Prothero, D. R. & Schoch, R. M.) 57–78 (Oxford Univ. Press, Oxford, 1989)

    Google Scholar 

  20. Gheerbrant, E., Sudre, J. & Cappetta, H. A Palaeocene proboscidean from Morocco. Nature 383, 68–70 (1996)

    Article  ADS  CAS  Google Scholar 

  21. Gheerbrant, E. et al. A new large mammal from the Ypresian of Morocco: evidence of surprising diversity of early proboscideans. Acta Palaeontol. Pol. 47, 493–506 (2002)

    Google Scholar 

  22. Coppens, Y., Maglio, V. J., Madden, C. T. & Beden, M. in Evolution of African Mammals (eds Maglio, V. J. & Cooke, H. B. S.) 336–367 (Harvard Univ. Press, Cambridge, 1978)

    Google Scholar 

  23. Harris, J. M. in Evolution of African Mammals (eds Maglio, V. J. & Cooke, H. B. S.) 315–332 (Harvard Univ. Press, Cambridge, 1978)

    Google Scholar 

  24. Court, N. A new species of Numidotherium (Mammalia: Proboscidea) from the Eocene of Libya and the early phylogeny of the Proboscidea. J. Vert. Paleontol. 15, 650–671 (1995)

    Article  Google Scholar 

  25. Tassy, P. La Place des Mastodontes Miocènes de l'Ancien Monde dans la Phylogénie des Proboscidea (Mammalia): Hypothèses et Conjectures. PhD thesis, Mèmoires des Sciences de la Terre. Univ. Pierre et Marie Curie, Paris 85-34, 1–862 (1985)

    Google Scholar 

  26. Pickford, M. Cainozoic paleontological sites of Western Kenya. Münchner Geowiss. Abhandlun. 8, 1–151 (1986)

    Google Scholar 

  27. Sanders, W. J. & Miller, E. R. New proboscideans from the early Miocene of Wadi Moghara. Egypt. J. Vert. Paleontol. 22, 388–404 (2002)

    Article  Google Scholar 

  28. Shoshani, J., Walter, R. C., Libsekal, Y., Abraha, M. & Berhe, S. in Sci. Prog. Abstr. 8th Int. Theriological Congr. 128–129 (Johannesburg, 2001)

    Google Scholar 

  29. Boschetto, H. B., Brown, F. H. & McDougall, I. Stratigraphy of the Lothidok Range, northern Kenya, and K/Ar ages of its Miocene primates. J. Hum. Evol. 22, 47–71 (1992)

    Article  Google Scholar 

Download references


We thank the Authority for Research and Conservation of Cultural Heritage, the Ministry of Culture and Sports Affairs, Ethiopia, for permission to conduct our ongoing research in the Blue Nile Basin, the Director and staff of the National Museum, Addis Ababa, for their assistance with collections, and the Gondar ARCCH for logistical support. The project is funded by grants from the National Science Foundation, the National Geographic Society, the L. S. B. Leakey Foundation, and the University Research Institute of UT Austin. W.J.S. was funded in part by a Scott Turner Award from the Department of Geological Sciences of The University of Michigan. A. Asfaw, M. Birara, F. Chanic, A. Kebede and T. Selassie provided field assistance, and M. Crawford and A. Neuenschwander aided with the interpretation of the satellite imagery. B. Miljour drafted Fig. 3. We are grateful to J.-J. Jaeger for comments and insights. We thank the people of the Chilga region for their hospitality and assistance in the fieldwork.

Author information

Authors and Affiliations


Corresponding author

Correspondence to John Kappelman.

Ethics declarations

Competing interests

The authors declare that they have no competing financial interests.

Supplementary information

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Kappelman, J., Tab Rasmussen, D., Sanders, W. et al. Oligocene mammals from Ethiopia and faunal exchange between Afro-Arabia and Eurasia. Nature 426, 549–552 (2003).

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI:

This article is cited by


By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.


Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing