Interesting Facts


       The Maiacetus inuus skeletons were discovered quite recently from 2000-2004. For only recovering three skeletons we have learned a lot about how they roamed the earth 47 million years ago (Gingerich et al. 2009). To learn more about how Maiacetus inuus roamed the earth visit           


     The female skeleton, with the near term fetus, was discovered first. After examining the skeleton researchers knew it belonged to the Family Protocetidae, but could not link it to any of the other organisms in the family. This new organism needed a genus and species. The animal was named both for its sex and being the first type of its organism to be discovered (Gingerich et al. 2009). The genus name came from Maia meaning mother, and Ketos meaning whale in Greek. Inuus is Latin for god of fecundity. The species name acknowledges how the discovery of the near term fetus impacted the cetacean fossil record (Gingerich et al. 2009). The disclosure of these skeletons was an important life history discovery in mammal evolution from land to sea.

        The discovery of this ancient mammal makes it challenging to learn about their years on earth. Studying behavior and interactions can be very difficult for scientists.  Evidence suggests that sexual dimorphism played a large role in mating for Maiacetus inuus (Gingerich et al. 2009). Some examples of sexual dimorphic traits would include male body size and protocones on the upper molars of males. It is believed that sexual dimorphism was practiced early in the evolution of Cetaceans (Gingerich et al. 2009).              

       Lastly an important piece of evidence that supports whale evolution from terrestrial mammals is tail movement. Members of the order Cetacea, such as whales and dolphins, move their fluked tails vertically. When you compare organisms in the order Cetacea to other aquatic organisms, like fish, they move their tailfins horizontally (Berkley 2014).  Land mammals have backbones that inhibit a natural side-to-side movement. This lack of motion caused early cetaceans, like the Maiacetus inuus, to depend on a vertical movement of their tail to help propel them through water.

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