Re: Morgan Tears 3.
chris brochu (gator@mail.utexas.edu)
30 Oct 1995 16:45:26 GMT
In article <1995Oct30.150745.9210@arl.mil> Troy Kelley,
tkelley@hel4.brl.mil writes:
>I thought someone posted that elephants had some kind of aquatic
>ancestor? Didn't you see that Alex? Perhaps some kind of seal and
>elephants share a common ancestor (the elephant seal mabe?).
> I would not be surprised to find that elephants have been aquatic at one
>time.
> There was a pepsi commercial recently that showed an elephant swimming
>buy using his nose as sort of a snorkel. Apparently elephants can swim
>quite well using this technique.
Firstly, elephants and seals have nothing to do with each other.
Pinnipeds - whether monophyletic or not - are carnivorans; elephants are
tethytherian ungulates. Other than being placentals, they share little
in common.
The aquatic ancestry of elephants is questionable. Some early
proboscideans - Moerotherium, for example - show evidence of semiaquatic
ancestry, but others do not. Moerotherium could either represent the
ancestral form or a semiaquatic sidebranch - we cannot tell.
The semiaquatic proboscideans are all known from the Fayum deposits,
which include both fluvial and coastal deposits. Significantly, they are
only known from the fluvial sediments, not the coastal beds, where one
finds whales and sirenians.
Also, keep in mind that the last purported semiaquatic proboscideans were
Oligocene at the latest.
That elephants swim well is in keeping with their amniote identity.
Virtually all land vertebrates have some swimming capacity.
chris
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