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Friday, July 16, 2010

Manatees and Hippos

While at the zoo on Tuesday, I recorded this movie of a hippo swimming on my Droid*.


As I watched the big, grey beast go swimming by, I was struck by how much its appearance and manners resembled a manatee. I looked them up on the Interweb Tubes only to discover they aren't very closely related at all. It has to do with skeletal structure, something obscured by all that flesh on both of them.

Hippos (order Artiodactyla)
Despite their physical resemblance to pigs and other terrestrial even-toed ungulates, their closest living relatives are cetaceans (whales, porpoises, etc.) from which they diverged about 55 million years ago.
Manatees (order Sirenia)
Manatees comprise three of the four living species in the order Sirenia. The 4th is the Eastern Hemisphere's dugong. The Sirenia are thought to have evolved from four-legged land mammals over 60 million years ago, with the closest living relatives being the Proboscidea (elephants) and Hyracoidea (hyraxes).
The taxonomical proximity (say that three times fast) seems backwards from appearances. Hippos are most closely related to whales while manatees are most closely related to elephants. Wild.

* - To be clear, I recorded the movie on my Droid, the hippo was not swimming on my Droid. While my Droid is incredibly capable, I don't think it can be used as a flotation device for hippos. Of course, experimentation may prove otherwise, but I remain skeptical.

5 comments:

  1. Oh boy. I get to type something that I never get to type. But finally I have found the context. I can hardly contain my excitement. Stop trembling, fingers, and prepare yourselves. My favorite mammal of all time:

    STELLAR SEA COW

    Woot! Whooh Hooh! Yes!

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  2. No one has found the common ancestor of hippos and whales. Personally I think that the morphology of hippos and manatees demonstrates a common ancestor....which may or may not be shared with whales because no one knows for certain. When dealing with the possibility of diverging evolution 55 mya the bottom line is NO ONE REALLY KNOWS.....and science is in the dark on much of the speculation regarding evolutionary trees. So until a genetic study is done comparing hippos and manatees showing hippos are more closely related to whales.....I'm sticking with the hypothesis that they're closely related 😉😉

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  3. Anonymous7:14 PM

    Hippos are land-whales, deal with it. This was settled by the odds of natural selection before you or I were ever born.

    https://www.rom.on.ca/en/blog/hippos-and-whales-unlikely-cousins

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