Fossil Evidence for the Origin of Aquatic Locomotion in Archaeocete Whales

  title={Fossil Evidence for the Origin of Aquatic Locomotion in Archaeocete Whales},
  author={J. G. M. Thewissen and S. Taseer Hussain and Muhammad Arif},
  pages={210 - 212}
Recent members of the order Cetacea (whales, dolphins, and porpoises) move in the water by vertical tail beats and cannot locomote on land. Their hindlimbs are not visible externally and the bones are reduced to one or a few splints that commonly lack joints. However, cetaceans originated from four-legged land mammals that used their limbs for locomotion and were probably apt runners. Because there are no relatively complete limbs for archaic archaeocete cetaceans, it is not known how the… 

New whale from the Eocene of Pakistan and the origin of cetacean swimming

This is the oldest fossil whale described from deep-neritic shelf deposits, and it shows that tail swimming evolved early in the history of cetaceans.

Transition of Eocene Whales from Land to Sea: Evidence from Bone Microstructure

This study highlights the strong need for homologous sections in comparative microanatomical studies, and the importance of combining information from several bones of the same taxon for improved functional interpretation.

The earliest known fully quadrupedal sirenian

Eocene fossils from Jamaica are described that represent nearly the entire skeleton of a new genus and species of sirenian—the most primitive for which extensive postcranial remains are known and one of the most marked examples of morphological evolution in the vertebrate fossil record.

Functional Morphology of the Vertebral Column in Remingtonocetus (Mammalia, Cetacea) and the Evolution of Aquatic Locomotion in Early Archaeocetes.

It is suggested that the evolution of tail-powered swimming in early cetaceans was preceded by an increase in lumbar mobility, and the vertebral morphology of an early archaeocete (Remingtonocetus domandaensis) is documents and quantitative methods for assessing vertebral function in fossil forms are developed.

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Land-to-sea transition in early whales: evolution of Eocene Archaeoceti (Cetacea) in relation to skeletal proportions and locomotion of living semiaquatic mammals

It appears that the land-to-sea transition in whale evolution involved at least two distinct phases of locomotor specialization: hindlimb domination for drag-based pelvic paddling in protocetids (Rodhocetus), with tail elongation for stability, followed by lumbus domination for lift-based caudal undulation and oscillation in basilosaurids (Dorudon).

General aspects of the evolutionary history of whales and dolphins

Recently discovered archaeocetes with large, mesonychid-like heads and dentitions and functional hind limbs reconfirm earlier ideas about the mesonychids origin of cetaceans and the amphibious nature of the earliest transitional forms.

Carpal Morphology and Function in the Earliest Cetaceans

ABSTRACT During the land-to-water transition in the Eocene epoch, the cetacean skeleton underwent modifications to accommodate life in the seas. These changes are well-documented in the fossil

Biomechanical Perspective on the Origin of Cetacean Flukes

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  • Biology, Environmental Science
  • 2006
A biomechanical analysis of extant species is required to evaluate mechanisms by which the flukes of cetaceans would have evolved and permits a functional interpretation of the limited fossil remains of primitive cetACEans.


  • S. Madar
  • Geography
    Journal of Paleontology
  • 2007
When both postcranial morphology and microstructure are considered, it can be concluded that pakicetid cetaceans were highly adapted for an aquatic niche.



Comparison of Swimming Kinematics between Terrestrial and Semiaquatic Opossums

Transition to exclusive hind limb paddling in semiaquatic mammals appears to be associated with development of non-wettable fur for increased buoyancy and with increased swimming effectiveness resulting from lack of interference between forelimbs and hind limbs during the stroke cycle.

Origin of underwater hearing in whales

The incus and mandible of Pakicetus indicate that the path of soundwaves to its ear resembled that of land mammals, and corroborate the hypothesis that artiodactyls are the closest extant relatives of cetaceans.

Origin of Whales in Epicontinental Remnant Seas: New Evidence from the Early Eocene of Pakistan

Discovery of Pakicetus strengthens earlier inferences that whales originated from terrestrial carnivorous mammals and suggests that whales made a gradual transition from land to sea in the early Eocene, spending progressively more time feeding on planktivorous fishes in shallow seas and embayments associated with tectonic closure of eastern Tethys.


The abundance and diversity of cetaceans and tethytheres at Ganda Kas suggests marked affinities of South Asian faunas with the other major Tethyan Eocene assemblage at Fayum, Egypt.


  • Zool. Soc. London
  • 1919

Clues to the origin of whales

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    • Natl. Geogr. Res. ExpL
    • 1993

    Wyss, and the Geological Survey of Pakistan. Field work was supported by the National Geographic Society

      Basilosaurus has 21 (16), ziphiids have 19, and physeterids have 24

      • Pachyaena has 15 caudal vertebrae (22)