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The postcranial skeleton of early Eocene pakicetid cetaceans

Published online by Cambridge University Press:  14 July 2015

S. I. Madar
S. I. Madar*
Affiliation:
Department of Biology, Hiram College, Hiram, Ohio 44234
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Abstract

A comparative analysis of the postcranial skeletal morphology of three species of pakicetid cetaceans provides new insights into their locomotor behavior. in gross morphology, they are similar to their smaller early artiodactyl relatives, lacking obvious signs of their transition to an aquatic niche. Features linking them are related to a cursorial adaptation centered in the reduction of joint mobility to the parasagittal plane, evident in both the elbow and the ankle. in addition to cursorial features of the limbs, the earliest whales and early artiodactyls both possess a long, stable lumbus and robust tails. the three pakicetid genera can be distinguished by size, proportion, and details of articular morphology. However, all pakicetid postcrania bear microstructural specializations commensurate with aquatic locomotion, and incompatible with cursoriality. the most striking modification is the presence of systemic increased bone density, likely used as skeletal ballast. When both postcranial morphology and microstructure are considered, it can be concluded that pakicetid cetaceans were highly adapted for an aquatic niche. As in several extant semiaquatic taxa, the pakicetid tail undoubtedly contributed to its locomotor repertoire, whether in propulsion or stabilization.

Type
Research Article
Information
Journal of Paleontology , Volume 81 , Issue 1 , January 2007 , pp. 176 - 200
Copyright
Copyright © The Paleontological Society 

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References

Aslan, A., and Thewissen, J. G. M. 1996. Preliminary evaluation of paleosols and implications for interpreting vertebrate fossil assemblages, Kuldana Formation, Northern Pakistan. Paleovertebrata, 25:261–277.Google Scholar
Barnes, L. G. 1990. The fossil record and evolutionary relationships of the genus Tursiops , p. 3–26. In Leatherwood, S. and Reeves, R. R. (eds.), The Bottlenosed Dolphin. Academic Press, New York.Google Scholar
Brunnich, M. 1771. Zoologiae fundamenta praelectoribus academicus accomodata. Hafniae (= Kobenhaven) et Lipsiae (Leipzig), Apud Frider. Christ. Pelt: 1–253.Google Scholar
Buffrénil, V. de, de Ricqlès, A., Ray, C. E., and Domning, D. P. 1990. Bone histology of the ribs of the archaeocetes (Mammalia, Cetacea). Journal of Vertebrate Paleontology, 10:455–466.CrossRefGoogle Scholar
Cope, E. D. 1868. An addition to the vertebrate fauna of the Miocene period, with a synopsis of the extinct Cetacea of the United States. Proceedings of the Academy of Natural Sciences of Philadelphia, 19:138–156.Google Scholar
Dehm, R., and zu Oettingen-Spielberg, T. 1958. Paläontologische und geologische Untersuchungen im tertiär von Pakistan. 2. Die mitteleocänen Saügetierre von Ganda Kas bei Basal in Nordwest Pakistan. Abhandlungen der Bayerische Akademie der Wissenschaften, Mathematisch-Naturwissenschaftliche Klasse, München, Neue Folge, 91:1–54.Google Scholar
Domning, D. P., and de Buffrénil, V. 1991. Hydrostasis in the Sirenia: Quantitative data and functional interpretations. Marine Mammal Science, 7:331–368.Google Scholar
Erfurt, J., and Haubold, H. 1989. Artiodactyla aus den eozänen Braunkholen des Geiseltales bei Halle (DDR). Paleovertebrata, 19:131–160.Google Scholar
Fish, F. E. 2001. A mechanism for evolutionary transition in swimming mode by mammals, p. 261–287. In Mazin, J.-M. and de Buffrénil, V. (eds.), Secondary Adaptations of Tetrapods to Life in Water. Verlag Dr. Friedrich Pfeil, München.Google Scholar
Fish, F. E., and Stein, B. R. 1991. Functional correlates of differences in bone density among terrestrial and aquatic genera in the family Mustelidae (Mammalia). Zoomorphology, 110:339–345.Google Scholar
Flower, W. H. 1869. On the osteology of the cachalot or sperm-whale (Physeter macrocephalus). Transactions of the Zoological Society of London, 6:309–372.Google Scholar
Flower, W. H. 1885. An Introduction to the Osteology of the Mammalia. Macmillan, London, 382 p.Google Scholar
Gatesy, J. 1998. Molecular evidence for the phylogenetic affinities of Cetacea, p. 63–112. In Thewissen, J. G. M. (ed.), The Emergence of Whales: Early Patterns in the Origin of Cetacea. Plenum Press, New York.Google Scholar
Geisler, J. H. 2001. New morphological evidence for the phylogeny of Artiodactyla, Cetacea, and Mesonychidae. American Museum Novitates, 3344:1–53.Google Scholar
Geisler, J. H., and Luo, Z. 1998. Relationships of Cetacea to terrestrial ungulates and the evolution of cranial vasculature in Cete, p. 163–212. In Thewissen, J. G. M. (ed.), The Emergence of Whales. Plenum Press, New York.Google Scholar
Geisler, J. H., and Sanders, A. E. 2003. Morphological evidence for the phylogeny of Cetacea. Journal of Mammalian Evolution, 10:23–130.Google Scholar
Geisler, J. H., and Uhen, M. D. 2003. Morphological support for a close relationship between hippos and whales. Journal of Vertebrate Paleontology, 23:991–996.Google Scholar
Gentry, A. W., and Hooker, J. J. 1988. The phylogeny of the Artiodactyla, p. 235–272. In Benton, M. J. (ed.), The Phylogeny and Classification of Tetrapods. Oxford University Press, London.Google Scholar
Gibbes, R. W. 1845. Description of the teeth of a new fossil animal found in the Green Sand of South Carolina. Proceedings of the Academy of Natural Sciences, Philadelphia, 1:2–15.Google Scholar
Gingerich, P. D. 1990. Prediction of body mass in mammalian species from long bone lengths and diameters. Contributions from the Museum of Paleontology, University of Michigan, 28:79–92.Google Scholar
Gingerich, P. D., Arif, M., and Clyde, W. C. 1995. New archaeocetes (Mammalia, Cetacea) from the middle Eocene Domanda Formation of the Sulaiman Range; Punjab (Pakistan). Contributions from the Museum of Paleontology, University of Michigan, 29:291–230.Google Scholar
Gingerich, P. D., Smith, B. H., and Simons, A. L. 1990. Hind limbs of Eocene Basilosaurus: Evidence of feet in whales. Science, 249:154–157.Google Scholar
Gingerich, P. D., ul Haq, M., Zalmout, I. S., Kahn, I. H., and Sadiq Malkani, M. 2001. Origin of whales from early artiodactyls: Hands and feet of Eocene Protocetidae from Pakistan. Science, 293:2239–2242.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, 220:403–406.CrossRefGoogle ScholarPubMed
Gray, J. E. 1868. Synopsis of the species of whales and dolphins in the collection of the British Museum. Bernard Quaritch, London.Google Scholar
Guthrie, D. A. 1968. The tarsus of early Eocene artiodactyls. Journal of Mammalogy, 49:297–302.CrossRefGoogle ScholarPubMed
Harlan, R. 1834. Notice of fossil bones found in the Tertiary formation of the state of Louisiana. Transactions of the American Philosophical Society, Philadelphia, 4:397–403.Google Scholar
Heyning, J. E. 1989. Comparative facial anatomy of beaked whales (Ziphiidae) and a systematic revision among the families of extant Odontoceti. Natural History Museum of Los Angeles County Contributions to Science, 405:1–64.Google Scholar
Hussain, S. T., Sondaar, P. Y., Ibrahim Shah, S. M., Thewissen, J. G. M., Cousin, E. F. H. M., and Spoor, C. F. 1983. Fossil mammal bones of Pakistan—A field atlas, Pt. I, The artiodactyl astragalus. Memoirs of the Geological Survey of Pakistan, 14:1–16.Google Scholar
Janis, C. M., and Scott, K. M. 1987. The phylogeny of the Ruminantia (Artiodactyla, Mammalia), p. 273–282. In Benton, M. J. (ed.), The Phylogeny and Classification of Tetrapods. Oxford University Press, London.Google Scholar
Linnaeus, Carolus. 1758. Systema Naturae. Holmiae, 1758, 8vo., Ed. 10, I, p. 1–824.Google Scholar
Luckett, W. P., and Hong, N. 1998. Phylogenetic relationships between the orders Artiodactyla and Cetacea: A combined assessment of morphological and molecular evidence. Journal of Mammalian Evolution, 5:127–182.CrossRefGoogle Scholar
Madar, S. I. 1998. Structural adaptations of early archaeocete long bones, p. 353–378. In Thewissen, J. G. M. (ed.), The Emergence of Whales: Early Patterns in the Origin of Cetacea. Plenum Press, New York.Google Scholar
Madar, S. I., and Thewissen, J. G. M. 2003. Locomotor morphology of pakicetid cetaceans: Evidence from gross morphology and skeletal ultrastructure. Journal of Vertebrate Paleontology, 23(suppl. 3):63.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, 22:405–422.CrossRefGoogle Scholar
Martinez, J-N., and Sudre, J. 1995. The astragalus of Paleogene artiodactyls: Comparative morphology, variability and prediction of body mass. Lethaia, 28:197–209.Google Scholar
McLeod, N., and Rose, K. D. 1993. Inferring locomotor behavior in Lower Tertiary mammals based on modern analogues via eigenshape analysis. American Journal of Science, 293-A:300–355.CrossRefGoogle Scholar
Messenger, S. L., and McGuire, J. A. 1998. Morphology, molecules, and the phylogenetics of cetaceans. Systematic Biology, 47:90–124.Google Scholar
Miller, G. S. Jr. 1923. The telescoping of the cetacean skull. Smithsonian Miscellaneous Collections, 75:1–55.Google Scholar
Muizon, C. de. 1987. The affinities of Notocetus vanbenedeni, an early Miocene platanistoid (Cetacea, Mammalia) from Patagonia, Southern Argentina. American Museum Novitates, 2904:1–27.Google Scholar
Muizon, C. de. 1988. Les relations des Delphinida (Cetacea, Mammalia). Annales de Paléontologie, 74:159–227.Google Scholar
Muizon, C. de. 1994. Are squalodonts related to the platanistoids?, p. 35–93. In Berta, A. and Deméré, T. A. (eds.), Contributions in Marine Mammal Paleontology Honoring Frank C. Whitmore, Jr. Proceedings of the San Diego Society of Natural History, 29.Google Scholar
Naylor, G. J. P., and Adams, D. C. 2001. Are the fossil data really at odds with the molecular data? Morphological evidence for Cetartiodactyla phylogeny re-examined. Systematic Biology, 50:444–453.Google Scholar
Nikaido, M., Rooney, A. P., and Okada, N. 1999. Phylogenetic relationships among cetartiodactyls based on insertions of short and long interspersed elements: Hippopotamuses are the closest extant relatives of whales. Proceedings of the National Academy of Science, USA, 96:10261–10266.CrossRefGoogle Scholar
O'Leary, M. A. 1999. Parsimony analysis of total evidence from extinct and extant taxa and the cetacean-artiodactyl question (Mammalia, Ungulata). Cladistics, 15:315–330.Google Scholar
O'Leary, M. A. 2001. The phylogenetic position of cetaceans: Further combined data analyses, comparisons with the stratigraphic record and a discussion of character optimization. American Zoologist, 41:487–506.Google Scholar
O'Leary, M. A., and Geisler, J. H. 1999. The position of Cetacea within Mammalia: Phylogenetic analysis of morphological data from extinct and extant taxa. Systematic Biology, 48:455–490.Google Scholar
O'Leary, M. A., and Rose, K. D. 1995. Postcranial skeleton of the early Eocene mesonychid Pachyaena (Mammalia: Mesonychia). Journal of Vertebrate Paleontology, 15:401–430.CrossRefGoogle Scholar
Roe, L. J., Thewissen, J. G. M., Quade, J., O'Neil, J. R., Bajpai, S., Sahni, A., and Hussain, S. T. 1998. Isotopic approaches to understanding the terrestrial-to-marine transition of the earliest cetaceans, p. 399–422. In Thewissen, J. G. M. (ed.), The Emergence of Whales: Early Patterns in the Origin of Cetacea. Plenum Press, New York.Google Scholar
Rose, K. D. 1982. The skeleton of Diacodexis, oldest known artiodactyl. Science, 216:621–623.Google Scholar
Rose, K. D. 1985. Comparative osteology of North American dichobunid artiodactyls. Journal of Paleontology, 59:1203–1226.Google Scholar
Sanders, A. E., and Barnes, L. G. 2002a. Paleontology of the Late Oligocene Ashley and Chandler Bridge formations of South Carolina. 2: Micromysticetus rothauseni, a primitive cetotheriid mysticete (Mammalia, Cetacea), p. 271–293. In Emry, R. J. (ed.), Cenozoic Mammals of Land and Sea: Tributes to the Career of Clayton E. Ray. Smithsonian Contributions to Paleobiology, 93:1–372.Google Scholar
Schaeffer, B. 1947. Notes on the origin and function of the artiodactyl tarsus. American Museum Novitates, 1356:1–24.Google Scholar
Schaeffer, B. 1948. The origin of a mammalian ordinal character. Evolution, 2:164–175.Google Scholar
Scott, K. M., and Janis, C. M. 1993. Relationships of the Ruminantia (Artiodactyla, Mammalia), and an analysis of the characters used in ruminant taxonomy, p. 282–302. In Szalay, F. S., Novacek, M. J., and McKenna, M. C. (eds.), Mammal Phylogeny. Volume 2. Placentals. Springer Verlag, New York.Google Scholar
Shoshani, J. 1986. Mammalian phylogeny: Comparison of morphological and molecular results. Molecular Biology and Evolution, 3:222–242.Google Scholar
Taylor, M. A. 1994. Stone, bone or blubber? Buoyancy control strategies in aquatic tetrapods, p. 151–161. In Maddock, L., Bone, Q., and Rayner, J. M. V. (eds.), Mechanics and Physiology of Animal Swimming. Cambridge University Press, Cambridge.Google Scholar
Theodor, J. M. 2004. Molecular clock divergence estimates and the fossil record of Cetartiodactyla. Journal of Paleontology, 78:39–44.Google Scholar
Thewissen, J. G. M. 1994. Phylogenetic aspects of cetacean origins: A morphological perspective. Journal of Mammalian Evolution, 2:157–184.Google Scholar
Thewissen, J. G. M., and Domning, D. E. 1992. The role of phenacodontids in the origin of the modern orders of ungulate mammals. Journal of Vertebrate Paleontology, 12:494–504.CrossRefGoogle Scholar
Thewissen, J. G. M., and Fish, F. E. 1997. Locomotor evolution in the earliest cetaceans: Functional model, modern analogues, and paleontological evidence. Paleobiology, 23:482–490.Google Scholar
Thewissen, J. G. M., and Hussain, S. T. 1990. Postcranial osteology of the most primitive artiodactyl Diacodexis pakistanensis (Dichobunidae). Anatomia Histologia Embryologia, 19:37–48.Google Scholar
Thewissen, J. G. M., and Hussain, S. T. 1998. Systematic review of the Pakicetidae, early and middle Eocene Cetacea (Mammalia) from Pakistan and India. Bulletin of the Carnegie Museum of Natural History, 34:220–238.Google Scholar
Thewissen, J. G. M., and Madar, S. I. 1998. Ankle morphology of the earliest cetaceans and its implications for the phylogenetic relations among ungulates. Systematic Biology, 48:21–30.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, 263:210–212.Google Scholar
Thewissen, J. G. M., Madar, S. I., and Hussain, S. T. 1996. Ambulocetus natans, an Eocene cetacean (Mammalia) from Pakistan. Courier Forschungsinstitut Senckenberg, 191:1–86.Google Scholar
Thewissen, J. G. M., Williams, E. M., and Hussain, S. T. 2001a. Eocene mammal faunas from northern Indo-Pakistan. Journal of Vertebrate Paleontology, 21:347–366.CrossRefGoogle Scholar
Thewissen, J. G. M., Williams, E. M., Roe, L. J., and Hussain, S. T. 2001b. Skeletons of terrestrial cetaceans and the relationship of whales to artiodactyls. Nature, 413:277–281.Google Scholar
Uhen, M. D. 2004. Form, Function and Anatomy of Dorudon Atrox (Mammalia, Cetacea): An Archaeocete from the Middle to Late Eocene of Egypt. Contributions from the Museum of Paleontology, University of Michigan, Ann Arbor, 222 p.Google Scholar
Uhen, M. D., and Gingerich, P. D. 2000. New genus of dorudontine archaeocete (Cetacea) from the middle-to-late Eocene of South Carolina. Marine Mammal Science, 17:1–34.CrossRefGoogle Scholar
Vernejoul, M. C. de, and Bénichou, O. 2001. Human osteopetrosis and other sclerosing disorders: Recent genetic developments. Calcified Tissue International, 69:1–6.CrossRefGoogle ScholarPubMed
Webb, S. D., and Taylor, B. E. 1980. The phylogeny of hornless ruminants and a description of the cranium of Archaeomeryx . Bulletin of the American Museum of Natural History, 167:121–157.Google Scholar
West, R. M. 1980. Middle Eocene large mammal assemblage with Tethyan affinities, Ganda Kas region, Pakistan. Journal of Paleontology, 54:508–533.Google Scholar
Yablokov, A. V. 1964. Convergence or parallelism in the evolution of cetaceans. International Geological Review, 7:1461–1468.Google Scholar
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