Hairy Museum of Natural History

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  Credit: John Klausmeyer,
  University of Michigan
  Museums of Natural History.
  From the U. of Mich. press release.

• New Mammal: Maiacetus inuus
• Name Means: Fecund Mother whale
• Relations: Protocetid whale
• Holotype: GSP-UM 3475a, partial skeleton of an adult female, containing the partially ossified skeleton of a near-term fetus (GSP-UM 3475b)
• Location: Balochistan Province, Pakistan
• Age: Middle Eocene, ~47,500,000 years old
• Length: ~2.5 meters (about 8 feet)
• Info: Artist’s conception of male Maiacetus inuus as it would have appeared in life.
  Credit: John Klausmeyer, University of Michigan Museums of Natural History.
• A team of paleontologists led by Philip Gingerich have described a new species of early whale. Buried along the shrinking shores of the Tethys Sea (and collected well above sea level in present-day Pakistan), the holotype of Maiacetus is the partial skeleton of a pregnant mother, preserved with the remains of its near-term fetus still in its womb. A more complete skeleton found one kilometer away is thought to be male, due to differences in size and pelvic proportion, and shows that this early whale retained the ancestral ability to stroll the shores on four fully-functional limbs (including an artiodactyl-style “double-pulley” ankle). The position of the fetus in the female indicates that Maiacetus gave birth head-first and most certainly on land, unlike modern whales that give birth tail-first into the water, which reduces the risk of drowning and helps orient the newborns parallel to their mothers. There are several excellent articles around the blogosphere for those who want to learn more, and the description is freely accessible through PLoS ONE at the link below.
  Fossils of female Maiacetus inuus with near-term fetus in utero, as found in the field. The female’s skull is shaded white (teeth brown), and other parts of her skeleton are shaded red. The single fetus, in birth position inside the mother whale, is shaded blue (teeth orange). The specimen was collected in three plaster jackets (blue dashed lines), and additional bones were picked up separately. The red dashed line indicates the edge exposed by erosion.
  Copyright: University of Michigan Museum of Paleontology.
• Reference: Gingerich, P. D., Haq, M-u., von 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(2): e4366. doi:10.1371/journal.pone.0004366.
• Further Reading:
  • University of Michigan Press Release
  • Greg Laden’s Blog: Amazing Fossil Finding: Proto Whales Gave Birth on Land, not at sea
  • Laelaps: Maiacetus, the good mother whale
  • The Loom: The Backward Whale
  • Not Exactly Rocket Science: Fossil foetus shows that early whales gave birth on land
  • The Questionable Authority: A Fossil Fetus and what it can tell us about the life history of early whales.

—Matt Celeskey.

File under: Mammals, Paleogene.