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A new archaeocete and other marine mammals (Cetacea and Sirenia) from lower middle Eocene phosphate deposits of Togo

Published online by Cambridge University Press:  14 July 2015

Philip D. Gingerich
Affiliation:
Department of Earth and Environmental Sciences, Museum of Paleontology, University of Michigan, Ann Arbor, Michigan, 48109-1079, USA,
Henri Cappetta
Affiliation:
Equipe Paléontologie, UMR 5554 Institut des Sciences de l'Evolution, Université de Montpellier II – Sciences et Techniques du Languedoc, Place Eugène Bataillon, 34095 Montpellier Cedex 5, France,

Abstract

Lutetian lower middle Eocene phosphate deposits of Kpogamé-Hahotoé in Togo yield new information about whales and sea cows in West Africa. Most specimens are individual teeth and bones, collected as isolated elements, but some appear to have been associated. Most are conservatively interpreted to represent a new 300–400 kg protocetid archaeocete, Togocetus traversei. This genus and species is distinctly primitive for a protocetid in retaining a relatively small mandibular canal in the dentary and retaining a salient metaconid on the lower first molar (M1), but it is derived relative to earlier archaeocetes in having large, dense, osteosclerotic tympanic bullae. Mandibular canal size and large dense bullae are not as tightly linked in terms of function in hearing as previously thought. Postcranially Togocetus traversei had many characteristics found in other semiaquatic protocetids: a relatively long neck, mobile shoulder, digitigrade manus, large pelvis, well-developed hind limbs, and feet specialized for swimming. Loss of a fovea on the head of the femur indicates loss of the teres ligament stabilizing the hip, which is a derived specialization consistent with life in water. Protocetid specimens distinctly smaller and larger than those of Togocetus traversei indicate the presence of at least three protocetids at Kpogamé. Sirenian vertebral and rib pieces indicate the presence of a protosirenid and a dugongid. Finally, a vertebral centrum and piece of humerus appear to represent a large land mammal. A diverse fauna of archaic whales and early sirenians inhabited the western margin of Africa and the eastern Atlantic Ocean as early as 46–44 million years before present, showing that both cetaceans and sirenians were widely distributed geographically by this time.

Type
Research Article
Copyright
Copyright © The Paleontological Society 

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References

Abel, O. 1907. The genealogical history of the marine mammals. Annual Report of the Smithsonian Institution, 1907:473496.Google Scholar
Adam, P. J. 2009. Hind limb anatomy, p. 562565. In Perrin, W. F., Würsig, B., and Thewissen, J. G. M. (eds.), Encyclopedia of Marine Mammals, Second Edition. Academic-Elsevier Press, San Diego.Google Scholar
Adnet, S., Cappetta, H., and Tabuce, R. 2010. A middle-late Eocene vertebrate fauna (marine fish and mammals) from southwestern Morocco; preliminary report: age and palaeobiogeographical implications. Geological Magazine, 147:860870.CrossRefGoogle Scholar
Andrews, C. W. 1920. A description of new species of zeuglodont and of leathery turtle from the Eocene of southern Nigeria. Proceedings of the Zoological Society of London, 1919:309319.Google Scholar
Astibia, H., Bardet, N., Pereda-Suberbiola, X., Payros, A., Buffrénil, V. d., Elorza, J., Tosquella, J., Berreteaga, A., and Badiola, A. 2010. New fossils of Sirenia from the middle Eocene of Navarre (western Pyrenees): the oldest west European sea cow record. Geological Magazine, 147:665673.CrossRefGoogle Scholar
Bajpai, S., Domning, D. P., Das, D. P., and Mishra, V. P. 2009. A new middle Eocene sirenian (Mammalia, Protosirenidae) from India. Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen, 252/3:257267.Google Scholar
Bajpai, S. and Gingerich, P. D. 1998. A new Eocene archaeocete (Mammalia, Cetacea) from India and the time of origin of whales. Proceedings of the National Academy of Sciences U.S.A., 95:1546415468.Google Scholar
Bajpai, S., Thewissen, J. G. M., Kapur, V. V., Tiwari, B. N., and Sahni, A. 2006. Eocene and Oligocene sirenians (Mammalia) from Kachchh, India. Journal of Vertebrate Paleontology, 26:400410.Google Scholar
Berggren, W. A. and Pearson, P. N. 2005. A revised tropical to subtropical Paleogene planktonic foraminiferal zonation. Journal of Foraminiferal Research, 35:279298.CrossRefGoogle Scholar
Bourdon, E. and Cappetta, H. 2012. Pseudo-toothed birds (Aves, Odontopterygiformes) from the Eocene phosphate deposits of Togo, Africa. Journal of Vertebrate Paleontology, 32:965970.Google Scholar
Brisson, M.-J. 1762. Regnum Animale in Classes IX. Distributum, sive Synopsis Methodica. Lugduni Batavorum, Theodorum Haak, Leiden, 296 p.Google Scholar
Cappetta, H. and Traverse, M. 1988. Une riche faune de sélachiens dans le bassin à phosphate de Kpogamé-Hahotoé (Éocène moyen du Togo): note préliminaire et précisions sur la structure et l'âge du gisement. Geobios, Lyon, 21:359365.Google Scholar
Domning, D. P. 2001. The earliest known fully quadrupedal sirenian. Nature, 413:625627.CrossRefGoogle ScholarPubMed
Domning, D. P. and Gingerich, P. D. 1994. Protosiren smithae, new species (Mammalia, Sirenia), from the late middle Eocene of Wadi Hitan, Egypt. Contributions from the Museum of Paleontology, University of Michigan, 29:6987.Google Scholar
Domning, D. P., Morgan, G. S., and Ray, C. E. 1982. North American Eocene sea cows (Mammalia: Sirenia). Smithsonian Contributions to Paleobiology, 52:169.Google Scholar
Elouard, P. 1981. Découverte d'un archéocète dans les environs de Kaolack. Notes Africaines, Dakar, 109:810.Google Scholar
Fraas, E. 1904. Neue Zeuglodonten aus dem unteren Mitteleocän vom Mokattam bei Cairo. Geologische und Paläontologische Abhandlungen, Jena, 6:197220.Google Scholar
Gingerich, P. D. 2010. Cetacea, p. 873899. In Werdelin, L. and Sanders, W. J. (eds.), Cenozoic Mammals of Africa. University of California Press, Berkeley.Google Scholar
Gingerich, P. D., Cappetta, H., and Traverse, M. 1992. Marine mammals (Cetacea and Sirenia) from the middle Eocene of Kpogamé-Hahotoé in Togo (abstract). Journal of Vertebrate Paleontology, 12A:2930.Google Scholar
Gingerich, P. D., Haq, M., Khan, I. H., and Zalmout, I. S. 2001b. Eocene stratigraphy and archaeocete whales (Mammalia, Cetacea) of Drug Lahar in the eastern Sulaiman Range, Balochistan (Pakistan). Contributions from the Museum of Paleontology, University of Michigan, 30:269319.Google Scholar
Gingerich, P. D., Haq, M., v. Koenigswald, W., Sanders, W. J., Smith, B. H., and Zalmout, I. S. 2009. New protocetid whale from the middle Eocene of Pakistan: birth on land, precocial development, and sexual dimorphism. PLoS ONE, 4 (e4366):120.Google Scholar
Gingerich, P. D., Haq, M., Zalmout, I. S., Khan, I. H., and Malkani, M. S. 2001a. Origin of whales from early artiodactyls: hands and feet of Eocene Protocetidae from Pakistan. Science, 293:22392242.Google Scholar
Gingerich, P. D., Raza, S. M., Arif, M., Anwar, M., and Zhou, X. 1994. New whale from the Eocene of Pakistan and the origin of cetacean swimming. Nature, 368:844847.Google Scholar
Gingerich, P. D., Wells, N. A., Russell, D. E., and Shah, S. M. I. 1983. Origin of whales in epicontinental remnant seas: new evidence from the early Eocene of Pakistan. Science, 220:403406.Google Scholar
Gray, J. E. 1821. On the natural arrangement of vertebrose animals. London Medical Repository Monthly Journal and Review, 15:296310.Google Scholar
Halstead, L. B. and Middleton, J. A. 1974. New material of the archaeocete whale, Pappocetus lugardi Andrews, from the middle Eocene of Nigeria. Journal of Mining and Geology, 8:8185.Google Scholar
Halstead, L. B. and Middleton, J. A. 1976. Fossil vertebrates of Nigeria. Part II, 3.4, Archaeocete whale: Pappocetus lugardi Andrews, 1920. Nigerian Field, 41:131133.Google Scholar
Hautier, L., Sarr, R., Tabuce, R., Lihoreau, F., Adnet, S., Domning, D. P., Samb, M., and Hameh, P. M. 2012. First prorastomid sirenian from Senegal (western Africa) and the Old World origin of sea cows. Journal of Vertebrate Paleontology, 32:12181222.Google Scholar
Illiger, C. 1811. Prodromus systematis mammalium et avium additis terminis zoographicis utriusque classis. C. Salfeld, Berlin, 301 p.Google Scholar
Jenkins, F. A. and Camazine, S. M. 1977. Hip structure and locomotion in ambulatory and cursorial carnivores. Journal of Zoology, London, 181:351370.CrossRefGoogle Scholar
Johnson, A. K., Rat, P., and Lang, J. 2000. Le bassin sédimentaire à phosphates du Togo (Maastrichtien-Eocène): stratigraphie, environnements et évolution. Journal of African Earth Sciences, 30:183200.CrossRefGoogle Scholar
Kilinc, M. and Cotillon, P. 1977. Le gisement d'Hahotoé-Kpogamé (Tertiaire du Sud Togo) exemple de piège sédimentaire à sables phosphatés. Bulletin du Bureau de Recherches Géologiques et Minières, Deuxième Série, 1:4363.Google Scholar
Kumar, K. and Sahni, A. 1986. Remingtonocetus harudiensis, new combination, a middle Eocene archaeocete (Mammalia, Cetacea) from western Kutch, India. Journal of Vertebrate Paleontology, 6:326349.CrossRefGoogle Scholar
Madar, S. I. 2007. The postcranial skeleton of early Eocene pakicetid cetaceans. Journal of Paleontology, 81:176200.Google Scholar
Madar, S. I., Thewissen, J. G. M., and Hussain, S. T. 2002. Additional holotype remains of Ambulocetus natans (Cetacea, Ambulocetidae), and their implications for locomotion in early whales. Journal of Vertebrate Paleontology, 22:405422.CrossRefGoogle Scholar
McLeod, S. A. and Barnes, L. G. 2008. A new genus and species of Eocene protocetid archaeocete whale (Mammalia, Cetacea) from the Atlantic Coastal Plain. Natural History Museum of Los Angeles County Science Series, 41:7398.Google Scholar
Mead, J. G. and Fordyce, R. E. 2009. The therian skull: a lexicon with emphasis on the odontocetes. Smithsonian Contributions to Zoology, 627:1248.Google Scholar
Norris, K. S. 1968. The evolution of acoustic mechanisms in odontocete cetaceans, p. 297324. In Drake, E. T. (ed.), Evolution and Environment. Yale University Press, New Haven.Google Scholar
Nummela, S., Hussain, S. T., and Thewissen, J. G. M. 2006. Cranial anatomy of Pakicetidae (Cetacea, Mammalia). Journal of Vertebrate Paleontology, 26:746759.Google Scholar
Owen, R. 1855. On the fossil skull of a mammal (Prorastomus sirenoides Owen) from the island of Jamaica. Quarterly Journal of the Geological Society of London, 11:541543.Google Scholar
Owen, R. 1875. On fossil evidences of a sirenian mammal (Eotherium aegyptiacum) from the nummulitic Eocene of the Mokattam cliffs, near Cairo. Quarterly Journal of the Geological Society of London, 31:100105.CrossRefGoogle Scholar
Sahni, A. and Mishra, V. P. 1975. Lower Tertiary vertebrates from western India. Palaeontological Society of India, Monographs, 3:148.Google Scholar
Slansky, M. 1962. Contribution a l'étude géologique du bassin sédimentaire côtier du Dahomey et du Togo. Mémoires du Bureau de Recherches Géologiques et Minières, Orléans, 11:1270.Google Scholar
Slansky, M. 1980. Géologie des phosphates sédimentaires. Mémoires du Bureau de Recherches Géologiques et Minières, Orléans, 114:192.Google Scholar
Stromer, E. 1908. Die Archaeoceti des ägyptischen Eozäns. Beiträge zur Paläontologie und Geologie Österreich-Ungarns und des Orients, Vienna, 21:106178.Google Scholar
Stromer, E. 1910. Reptilien- und Fischreste aus dem marinen Alttertiär von Südtogo (Westafrika). Zeitschrift der Deutschen Geologischen Gesellschaft, Monatsberichte, Stuttgart, 62:478507.Google Scholar
Thewissen, J. G. M., Hussain, S. T., and Arif, M. 1994. Fossil evidence for the origin of aquatic locomotion in archaeocete whales. Science, 263:210212.CrossRefGoogle ScholarPubMed
Thewissen, J. G. M., Madar, S. I., and Hussain, S. T. 1996. Ambulocetus natans , an Eocene cetacean (Mammalia) from Pakistan. Courier Forschungsinstitut Senckenberg, Frankfurt am Main, 191:186.Google Scholar
Vandenberge, N., Hilgen, F. J., and Speijer, R. P. 2012. The Paleogene period, p. 855921. In Gradstein, F. M., Ogg, J. G., Schmitz, M. D., and Ogg, G. M. (eds.), The Geological Time Scale 2012. Elsevier, Amsterdam.Google Scholar
Williams, E. M. 1998. Synopsis of the earliest cetaceans: Pakicetidae, Ambulocetidae, Remingtonocetidae, and Protocetidae, p. 128. In Thewissen, J. G. M. (ed.), The Emergence of Whales: Evolutionary Patterns in the Origin of Cetacea. Plenum, New York.Google Scholar
Zalmout, I. S. and Gingerich, P. D. 2012. Late Eocene sea cows (Mammalia, Sirenia) from Wadi Al Hitan in the Western Desert, Fayum, Egypt. University of Michigan Papers on Paleontology, 37:1158.Google Scholar
Zalmout, I. S., Haq, M., and Gingerich, P. D. 2003. New species of Protosiren (Mammalia, Sirenia) from the early middle Eocene of Balochistan (Pakistan). Contributions from the Museum of Paleontology, University of Michigan, 31:7987.Google Scholar