Marine Notes

  • Trichechidae

    • Related to dugongidae and also aardvarks and elephant shrews

    • One of only mammals that do continuous horizontal tooth replacement

    • Lophodont

    • Their nostrils are on top, and they have no nasal bone, only a nasal vacuity

  • Whales

    • Oil is stored in the melon

      • Lots of oil in sperm whales (Moby Dick)

      • Sound resonates in melon and helps with navigation

      • Melon structure can also be used to sonically stun pray

      • Pygmy sperm whales have the most asymmetrical mammal skull

  • Dolphins

    • Hearing similar to bats

    • Ear structure goes into dentary which receives signal, sends it through oil, and finally the periotic

    • Homodont teeth

    • Plate pressing up against nasal is vomer

    • Orca has transverse processes