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Whales originated from aquatic artiodactyls in the Eocene epoch of India

Nature volume 450, pages 1190–1194 (2007)Cite this article

Abstract

Although the first ten million years of whale evolution are documented by a remarkable series of fossil skeletons, the link to the ancestor of cetaceans has been missing. It was known that whales are related to even-toed ungulates (artiodactyls), but until now no artiodactyls were morphologically close to early whales. Here we show that the Eocene south Asian raoellid artiodactyls are the sister group to whales. The raoellid Indohyus is similar to whales, and unlike other artiodactyls, in the structure of its ears and premolars, in the density of its limb bones and in the stable-oxygen-isotope composition of its teeth. We also show that a major dietary change occurred during the transition from artiodactyls to whales and that raoellids were aquatic waders. This indicates that aquatic life in this lineage occurred before the origin of the order Cetacea.

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Figure 1: Osteology of Indohyus and cross-sections of long bones of Eocene cetartiodactyls.
Figure 2: Phylogeny of artiodactyls, cetaceans and archaic ungulates.
Figure 3: Plot of the ratio of the thickness of the medial tympanic wall to that of the lateral tympanic wall against the natural logarithm of the width across occipital condyles, showing that the ratio in Indohyus is similar to that in cetaceans.
Figure 4: Bivariate plot of δ 18 O and δ 13 C values for enamel samples of early and middle Eocene mammals from India and Pakistan.
Figure 5: Skeletal reconstruction of Indohyus.

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References

  1. Milinkovitch, M. C., Bérubé, M. & Palsbøl, P. J. in The Emergence of Whales: Evolutionary Patterns in the Origin of Cetacea (ed. Thewissen, J. G. M.) 113–131 (Plenum, New York, 1998)

    Book  Google Scholar 

  2. Nikaido, M., Rooney, A. P. & Okada, N. Phylogenetic relationships among cetartiodactyls based on insertions of short and long interspersed elements: Hippopotamuses are the closest extant relatives of whales. Proc. Natl Acad. Sci. USA 96, 10261–10266 (1999)

    Article  ADS  CAS  Google Scholar 

  3. Gatesy, J. & O’Leary, M. A. Deciphering whale origins with molecules and fossils. Trends Ecol. Evol. 16, 562–570 (2001)

    Article  Google Scholar 

  4. Boisserie, J.-R., Lihoreau, F. & Brunet, M. Origins of Hippopotamidae (Mammalia, Cetartiodactyla): towards resolution. Zool. Scr. 34, 119–143 (2005)

    Article  Google Scholar 

  5. Thewissen, J. G. M., Williams, E. M., Roe, L. J. & Hussain, S. T. Skeletons of terrestrial cetaceans and the relationships of whales to artiodactyls. Nature 413, 277–281 (2001)

    Article  ADS  CAS  Google Scholar 

  6. Theodor, J. M. & Foss, S. E. Deciduous dentitions of Eocene cebochoerid artiodactyls and cetartiodactyl relationships. J. Mammal. Evol. 12, 161–181 (2005)

    Article  Google Scholar 

  7. O’Leary, M. A. in The Emergence of Whales: Evolutionary Patterns in the Origin of Cetacea (ed. Thewissen, J. G. M.) 133–161 (Plenum, New York, 1998)

    Book  Google Scholar 

  8. Boisserie, J.-R., Lihoreau, F. & Brunet, M. The position of Hippopotamidae within Cetartiodactyla. Proc. Natl Acad. Sci. USA 102, 1537–1541 (2005)

    Article  ADS  CAS  Google Scholar 

  9. Geisler, J. H. & Uhen, M. D. Morphological support for a close relationship between hippos and whales. J. Vertebr. Paleontol. 23, 991–996 (2003)

    Article  Google Scholar 

  10. Geisler, J. H. & Uhen, M. D. Phylogenetic relationships of extinct Cetartiodactyls: results of simultaneous analyses of molecular, morphological, and stratigraphic data. J. Mammal. Evol. 12, 145–160 (2005)

    Article  Google Scholar 

  11. Ranga Rao, A. New mammals from Murree (Kalakot zone) of the foot-hills near Kalakot, J & K State. J. Geol. Soc. India 12, 125–134 (1971)

    Google Scholar 

  12. Ranga Rao, A. & Misra, V. N. On the new Eocene mammal localities in the Himalayan foot-hills. Himalayan Geol. 11, 422–428 (1981)

    Google Scholar 

  13. Kumar, K. & Sahni, A. Eocene mammals from the Upper Subathu Group, Kashmir Himalaya, India. J. Vertebr. Paleontol. 5, 153–168 (1985)

    Article  Google Scholar 

  14. Thewissen, J. G. M., Williams, E. M. & Hussain, S. T. Eocene mammal faunas from northern Indo-Pakistan. J. Vertebr. Paleontol. 21, 347–366 (2001)

    Article  Google Scholar 

  15. Luo, Z. in The Emergence of Whales: Evolutionary Patterns in the Origin of Cetacea (ed. Thewissen, J. G. M.) 269–301 (Plenum, New York, 1998)

    Book  Google Scholar 

  16. Luo, Z. & Gingerich, P. D. Terrestrial Mesonychia to aquatic Cetacea: transformation of the basicranium and evolution of hearing in whales. Univ. Mich. Pap. Paleontol. 31, 1–98 (1999)

    Google Scholar 

  17. Thewissen, J. G. M & Williams, E. M. The early radiations of Cetacea (Mammalia): evolutionary pattern and developmental correlations. Annu. Rev. Ecol. Syst. 33, 73–90 (2002)

    Article  Google Scholar 

  18. O’Leary, M. A. & Uhen, M. D. The time of origin of whales and the role of behavioral changes in the terrestrial–aquatic transition. Paleobiology 25, 534–556 (1999)

    Article  Google Scholar 

  19. Nummela, S., Hussain, S. T. & Thewissen, J. G. M. Cranial anatomy of Pakicetidae (Cetacea, Mammalia). J. Vertebr. Paleontol. 26, 746–759 (2006)

    Article  Google Scholar 

  20. Gray, N. M., Kainec, K., Madar, S., Tomko, L. & Wolfe, S. Sink or swim? Bone density as a mechanism for buoyancy control in early cetaceans. Anat. Rec.: Adv. Int. Anat. Evol. Biol. 290, 638–653 (2007)

    Article  Google Scholar 

  21. Madar, S. I. The postcranial skeleton of early Eocene pakicetid cetaceans. J. Paleontol. 81, 176–200 (2007)

    Article  Google Scholar 

  22. Roe, L. J. et al. in The Emergence of Whales: Evolutionary Patterns in the Origin of Cetacea (ed. Thewissen, J. G. M.) 399–422 (Plenum, New York, 1998)

    Book  Google Scholar 

  23. Clementz, M. T., Goswami, A., Gingerich, P. D. & Koch, P. L. Isotopic records from early whales and sea cows: contrasting patterns of ecological transition. J. Vertebr. Paleontol. 26, 355–370 (2006)

    Article  Google Scholar 

  24. Francillon-Vieillot, H. et al. in Skeletal Biomineralization Patterns, Processes, and Evolutionary Trends (ed. Carter, J. G.) 471–530 (Van Nostrand Reinhold, New York, 1990)

    Google Scholar 

  25. de Buffrénil, V., Ricqlès, A., Ray, C. E. & Domning, D. P. Bone histology of the ribs of the archaeocetes (Mammalia: Cetacea). J. Vertebr. Paleontol. 10, 455–466 (1990)

    Article  Google Scholar 

  26. Kaiser, H. E. Untersuchungen zur vergleichenden Osteologie der Fossilen und rezenten Pachyostosen. Palaeontographica A 114, 113–196 (1960)

    Google Scholar 

  27. Domning, D. P. & de Buffrénil, V. Hydrostasis in the Sirenia: quantitative data and functional interpretations. Mar. Mamm. Sci. 7, 331–368 (1991)

    Article  Google Scholar 

  28. Fish, F. E. & Stein, B. R. Functional correlates of differences in bone density among terrestrial and aquatic genera in the family Mustelidae (Mammalia). Zoomorphology 110, 339–345 (1991)

    Article  Google Scholar 

  29. Wall, W. P. The correlation between high limb-bone density and aquatic habitats in recent mammals. J. Paleontol. 57, 197–207 (1983)

    Google Scholar 

  30. Taylor, M. A. Functional significance of bone ballast in the evolution of buoyancy control strategies by aquatic tetrapods. Histor. Biol 14, 15–31 (2000)

    Article  Google Scholar 

  31. Koch, P. L., Tuross, N. & Fogel, M. L. The effects of sample treatment and diagenesis on the isotopic integrity of carbonate in biogenic hydroxyapatite. J. Archaeol. Sci. 24, 417–429 (1997)

    Article  Google Scholar 

  32. Kohn, M. J. Predicting animal δ18O: accounting for diet and physiological adaptation. Geochim. Cosmochim. Acta 60, 4811–4829 (1996)

    Article  ADS  CAS  Google Scholar 

  33. Clementz, M. T. & Koch, P. L. Differentiating aquatic mammal habitat and foraging ecology with stable isotopes in tooth enamel. Oecologia 129, 461–472 (2001)

    Article  ADS  Google Scholar 

  34. Bocherens, H., Koch, P. L., Mariotti, A., Geraads, D. & Jaeger, J.-J. Isotopic biogeochemistry (13C, 18O) of mammalian enamel from African Pleistocene hominid sites. Palaios 11, 306–318 (1996)

    Article  ADS  Google Scholar 

  35. Bryant, J. D. & Froelich, P. N. A model of oxygen isotope fractionation in body water of large mammals. Geochim. Cosmochim. Acta 59, 4523–4537 (1995)

    Article  ADS  CAS  Google Scholar 

  36. Jim, S., Ambrose, S. H. & Evershed, R. P. Stable carbon isotopic evidence for differences in the dietary origin of bone cholesterol, collagen and apatite: Implications for their use in palaeodietary reconstruction. Geochim. Cosmochim. Acta 68, 61–72 (2004)

    Article  ADS  CAS  Google Scholar 

  37. Cloern, J. E., Canuel, E. A. & Harris, D. Stable carbon and nitrogen isotope composition of aquatic and terrestrial plants of the San Francisco Bay estuarine system. Limnol. Oceanogr. 47, 713–729 (2002)

    Article  ADS  CAS  Google Scholar 

  38. Osmond, C. B., Valaane, N., Haslam, S. M., Uotila, P. & Roksandic, Z. Comparisons of δ13C values in leaves of aquatic macrophytes from different habitats in Britain and Finland; some implications for photosynthetic processes in aquatic plants. Oecologia 50, 117–124 (1981)

    Article  ADS  CAS  Google Scholar 

  39. O’Leary, M. H. Carbon isotopes and photosynthesis. Bioscience 38, 328–336 (1988)

    Article  Google Scholar 

  40. Dubost, G. Un aperçu sur l’écologie du chevrotain africain Hyemoschus aquaticus Ogilby, artiodactyle tragulide. Mammalia 42, 1–62 (1978)

    Article  Google Scholar 

  41. Ducrocq, S. The late Eocene Anthracotheriidae (Mammalia, Artiodactyla) from Thailand. Palaeontographica A 252, 93–140 (1999)

    Google Scholar 

  42. Ducrocq, S. Unusual dental morphologies in late Eocene anthracotheres (Artiodactyla, Mammalia) from Thailand: dental anomalies and extreme variations. N. Jb. Geol. Paläont. MH 4, 199–212 (1999)

    Google Scholar 

  43. Suteethorn, V., Buffetaut, E., Helmcke-Ingavat, R., Jaeger, J. J. & Jongkanjanasoontorn, Y. Oldest known Tertiary mammals from South East Asia: middle Eocene primate and anthracotheres from Thailand. N. Jb. Geol. Paläont. MH 9, 563–570 (1988)

    Google Scholar 

  44. Colbert, E. H. Fossil mammals from Burma. Am. Mus. Nat. Hist. Bull. 74, 419–424 (1938)

    Google Scholar 

  45. Brunet, M. M. Découverte d’un crâne d’Anthracotheriidae, Microbunodon minimum (Cuvier), á La Milloque (Lot-et-Garonne). C. R. Acad. Sci. Paris 267, 835–838 (1968)

    Google Scholar 

  46. Lihoreau, F., Blondel, C., Barry, J. & Brunet, M. A new species of the genus Microbunodon (Anthracotheriidae, Artiodactyla) from the Miocene of Pakistan: genus revision, phylogenetic relationships and palaeobiogeography. Zool. Scr. 33, 97–115 (2004)

    Article  Google Scholar 

  47. Bajpai, S. et al. Early Eocene land mammals from Vastan Lignite Mine, District Surat, Gujarat, western India. J. Palaeontol. Soc. India 50, 101–113 (2005)

    Google Scholar 

  48. West, R. M. Middle Eocene large mammal assemblage with Tethyan affinities, Ganda Kas region, Pakistan. J. Paleontol. 54, 508–533 (1980)

    Google Scholar 

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Acknowledgements

We thank the late F. Obergfell for presenting us with the sediment blocks containing Indohyus fossils collected by A. Ranga Rao for preparation and study; D. S. N. Raju and N. Raju for facilitating our research; B. Armfield, R. Conley and A. Maas for fossil preparation; J. Dillard for preparing Fig. 5; and J. Geisler and J. Theodor for providing additional information about their cladistic analyses. Laboratory research was funded by the National Science Foundation (NSF) – Earth Sciences (grants to J.G.M.T. and M.T.C.). Collaborative work was funded by the Indian Department of Science and Technology (to S.B.) and the NSF – International Division (to J.G.M.T.) under the Indo-US Scientific Cooperation Program. Laboratory analyses were supported by the Skeletal Biology Research Focus Area of Northeastern Ohio Universities College of Medicine.

Author Contributions J.G.M.T. was responsible for anatomical and systematic study, and scientific synthesis, L.N.C. for systematic and bone density study, M.T.C. for the study of stable isotopes, and S.B. and B.N.T. for geological study and collecting of Indohyus and comparative fossil samples.

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Authors and Affiliations

  1. Department of Anatomy, Northeastern Ohio Universities College of Medicine, Rootstown, Ohio 44272, USA,

    J. G. M. Thewissen & Lisa Noelle Cooper

  2. School of Biomedical Sciences, Kent State University, Kent, Ohio 44242, USA,

    Lisa Noelle Cooper

  3. Department of Geology and Geophysics, University of Wyoming, Laramie, Wyoming 82071, USA,

    Mark T. Clementz

  4. Department of Earth Sciences, Indian Institute of Technology, Roorkee, Uttarakhand 247 667, India,

    Sunil Bajpai

  5. Wadia Institute of Himalayan Geology, Dehra Dun, Uttarakhand 248 001, India,

    B. N. Tiwari

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Correspondence to J. G. M. Thewissen.

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Thewissen, J., Cooper, L., Clementz, M. et al. Whales originated from aquatic artiodactyls in the Eocene epoch of India. Nature 450, 1190–1194 (2007). https://doi.org/10.1038/nature06343

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