Afrotheria

For our overview of Eutherian orders, we will use the phylogeny proposed by Murphy et al. (2001). Basal split = Afrotheria and all other orders

Afrotheria is composed of

All these lineages have African origins, but some have expanded their ranges beyond Africa.

  1. Order Afrosoricida

    1. Until very recently, this order was part of the large (>400 species) order called Insectivora. Several recent phylogenies have indicated that the group we knew as Insectivora was polyphyletic and was composed of 2 or 3 phylogenitically distinct lineages.
      1. Most (but not all) eat insects and small invertebrates
      2. Small body size
      3. Most are terrestrial, but some are fossorial, semi-aquatic or arboreal
      4. Pellage consists of only one type of hair + vibrissae
      1. Teeth

        1. Simple teeth
        2. Incisors tend to be enlarged and canines reduced (so that they're pretty close to the same size)

      1. Limbs are unspecialized, feet are plantigrade
    2. Examples:
      1. Tenrec
        1. Native to Madagascar
        2. Mouse- to rabbit-sized
        3. Long snout
        4. Small eyes
        5. Large pinnae
        6. Some have spines, others only have sparse, course guard hairs
        7. Can roll into a ball when threatened
        8. Ecology and behavior

          1) Stridulation
          2) One member of the family (otter shrew; subfamily Potamogalinae; African) is semi-aquatic

      2. Golden mole
        1. Fossorial
        2. Small eyes
        3. No pinnae
        4. Eats invertebrates

  1. Order Macroscelidea

    Common name Elephant shrews
    Families 1 (Macroscelididae)
    # of genera 4
    # of species 15
    Distribution Africa

    1. Characteristics of the order

      1. Resemble insectivores (and previously lumped with them taxonomically)
      2. Important differences between elephant shrews and other species that were lumped in with the insectivores:

        1. Have auditory bullae
        2. Have zygomatic arches
        3. Olfactory lobes are small
        4. Has a cecum

      1. Rat- to mouse-sized
      2. Large eyes, large ears
      3. Long, mobile snout (hence the common name)

    1. Ecology and behavior

      1. Habitat: dry places (plains, savannahs, forests)
      2. Live in open (don't burrow)
      3. Eat invertebrates (see teeth)
      4. Diurnal
      5. Fast movement by saltation, slow movement on all fours

    1. Reproduction

      1. Monogamous
      2. 1-2 precocial young

  1. Order Tubulidentata

    Common name aardvark
    # species 1 ( Orycteropus afer)
    Distribution Africa

    1. General characteristics of the order

      1. Now recognized as being part of the Afrotherian lineages, but in the past they were often lumped into a group called the edentates (contained anteaters, sloths, armadillos, and pangolins) because of shared adaptations for digging and eating ants/termites.
      2. The smallest living order
      3. Aardvark means "earth pig" in Afrikaans (appropriate because they are pig size and shape and are semifossorial)
    1. Morphology

      1. Skull is elongated
      2. Teeth

        1. No incisors or canines
        2. 5 cheek teeth top and bottom
        3. Cheek teeth are oval or figure-8 shaped
        4. Teeth have numerous tubular pulp cavities running vertically through each tooth (gives the order its name)

      3. Pig-like snout
      4. Long tongues
      5. Big ears
      6. Long, gradually-tapering tail with thick base
      7. Thick skin with bristles
      8. Digits have strong, hoof-like claws
      9. Roughened pyloric portion of stomach

    1. Ecology and behavior

      1. Eats termites, ants, other insects


    2. Picture of baby aardvark
    3. One more...

The next three orders are often referred to as Subungulates, because they were thought to be closely related phylogenetically to the orders Artiodactyla and Perissodactyla. According to Murphy et al. (2001) and others, this is probably not correct...

  1. Order Hyracoidea

    Common name hyrax
    # of genera 3
    # of species 4
    Distribution Africa

    1. General characteristics

      1. Rabbit-sized, resemble rodents
      2. Have enlarged, rootless incisors
      3. Incisors separated from cheek teeth by a diastema
      4. Weird feet for an animal in their niche

        1. Shortish toes
        2. Moist, glandular adhesive pads on feet
        3. Flat nails that resemble hooves
        4. Sharp grooming claw on the second digit of their foot

    1. Ecology and behavior

      1. Herbivorous
      2. Live on rocks and in trees
      3. Colonial

  1. Order Proboscidea

    1. General characteristics

      1. Teeth

        1. Top incisors are enlarged into tusks
        2. Tusks are rootless
        3. No canines
        4. Cheek teeth (6) are shed from the front as they are worn and replaced from the back

      1. Limbs (video clip)

        1. Thick and straight
        2. Five digits on each foot
        3. Most digits have a hoof-like nail

      1. Trunk

        1. Fusion and elongation of upper lip and nose
        2. Prehensile
        3. Nostrils are at the end

      1. Skin is thick and covered with bristles

    1. Two living species? Or perhaps three?

    Scientific name Elephas maximus Loxodonta africana Loxodonta cyclotis
    Common name Asian elephant African bush or savannah elephant African forest elephant
    Size up to 5000 kg, 3 m tall up to 7000 kg, 4 m tall up to 6000 kg, 2.5 m tall
    Ears Relatively smaller Really big Smaller and rounder than L. africanus
    Forehead Domed Flat Flat
    Tusks Males only Both sexes, curved Both sexes, straighter than L. africanus
    Back Convex Concave Concave

    1. Ecology and behavior

      1. Grazers
      2. Matrilineal social groups
      3. Asian elephant and to a lesser extent African elephant are used as beasts of burden (but have NOT been domesticated)
      4. Use infrasound for communication

  1. Order Sirenia

    Common names manatee, sea cow, dugong
    # of families 2 (Trichechidae, Dugongidae)
    # of genera 3
    # of species 5
    Distribution tropical or subtropical
    manatees: east coast of N and S America (N Carolina to Brazil), rivers in Florida and Brazil also West coast of Africa and river drainages
    dugong: Red Sea, Indian ocean, S.E. Asia, E coast of Asia, Australia

    1. General characteristics

      1. Fully aquatic
      2. Limbs

        1. lack hind limbs
        2. forelimbs modified as flippers

      1. Tail modified into flipper (extends laterally)
      2. Small eyes
      3. No pinnae
      4. External nares are high on the skull (on the upper surface of the snout), nasal bones are reduced or absent
        photo of nares closed when submerged
      5. Teeth

        1. Canines and sometimes incisors are absent
        2. Cheek teeth are lost from the front and replaced from the rear

      1. Lips are large and mobile
      2. Vibrissae on upper lip and body (otherwise hairless)

    1. Ecology and Behavior

      1. Eat aquatic vegetation