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Title: Modern Mammals


1
Modern Mammals
  • Characteristics of the mammals
  • Lactation Feed young on milk
  • Hair
  • Skeletal features
  • Heterodont dentition
  • Single jaw bone (dentary).
  • Two occipital condyles
  • Middle ear with three bones incus, malleus,
    stapes
  • Endothermy
  • Muscular diaphragm

2
Lactation
  • Lactation females of all mammals feed their
    young on milk produced by mammary glands.
  • Mammary glands are completely absent from male
    marsupials, but are present in male therians
    (monotremes and placental mammals) and
    potentially functional.
  • There are cases of human males producing milk and
    there is a species of fruit bat in which males
    produce milk.

3
Lactation
  • Although all mammals produce milk only marsupials
    and placentals have nipples.
  • In monotremes the milk seeps from pores in the
    skin and the young suck the milk from the
    mothers fur.

4
Hair
  • Hair has a variety of functions.
  • Obviously, insulation is its primary purpose.
    Fur is made up of closely placed hairs and the
    insulating value of the fur is a function of its
    length.
  • Longer hair allows more air to be trapped and
    this reduces heat loss.

5
Snow leopard http//metastwnsh.files.wordpress.com
/2008/11/calculation-snow-leopard1.jpg
6
Hair
  • Hairs can be erected by erector pili muscles that
    attach halfway along the hair shaft.
  • This raising of the fur increases the amount of
    air trapped and thus the insulation level. Hair
    may also be raised as a threat or defensive
    display.
  • Although humans lack fur we retain the erector
    pili muscles as vestigial structure and these
    produce goosebumps.

7
Hair
  • Hair is composed of keratin, a fibrous protein,
    and keratin is also used to make nails, hooves
    and claws.
  • Hair coloration is determined by melanocytes in
    the hair follicle that add different types and
    amounts of pigment to the hair as it develops.

8
Hair
  • Exposed hair is non-living and bleaches with age.
  • The replacement of the fur occurs in the process
    of molting in which old hairs are lost and
    replaced by new ones. Most mammals molt their
    hair seasonally once or twice.

9
Molting mountain goat http//ecolibrary.cs.brandei
s.edu/images/ thumb50/thumb50_Mountain_goat_moltin
g_DP4102.jpg
10
Hair
  • In addition to acting as insulation hair also
    plays an important role in camouflage.
  • The color pattern is the result of the mixing of
    a variety of different colored hairs.
  • Hair is also used for communication and threat
    displays often include puffing up the fur.

11
Vibrissae
  • Vibrissae (e.g. a cats or a seals whiskers) are
    special hairs that have a sensory function.
  • Vibrissae occur on the muzzle and around the eyes
    and they are connected to touch receptors in the
    skin.

12
Cats vibrissae http//upload.wikimedia.org/wikipe
dia/commons/3/39/Cats_whiskers.jpg
13
Claws, nails, horns and hooves
  • Keratin is used to make not only hair but nails,
    claws, hooves and horns.
  • Claws, nails and hooves are all the result of an
    initial accumulation of keratin to protect the
    bones making up the toe (phalanges) that was
    later modified in ungulates into hooves, which
    entirely cover the entire 3rd phalanx (the
    terminal bone of the toe) and into retractable
    claws in cats

14
http//osnhc.com/images/BASICHOOFANATOMY.jpg
15
Horns
  • Horns are also formed at least partially from
    keratin. Rhinoceros horns are made entirely of
    layers of keratin fibers.
  • In contrast, the horns of cows and antelopes are
    made up of a keratin sheath over a bony core.

16
White Rhinoceros http//www.mth.msu.edu/peller/Af
rica_large/rhinoceros.jpg
17
Skeletal features heterodont dentition
  • Heterodont dentition Mammals possess
    differentiated teeth (teeth that have different
    forms), which carry out different tasks
    incisors, canines premolars and molars.
  • Most mammals possess two sets of teeth.
  • The first set (milk teeth) has incisors, canines
    and premolars only.

18
Skeletal features heterodont dentition
  • The adult dentition consists of the second set of
    the original teeth plus a set of molars.
  • Mammals are the only animals that chew their food
    and the teeth are essential to this process,
    which initiates the digestive process beginning
    the mechanical breakdown of the food and
    introducing the first digestive enzymes into the
    food bolus.

19
Skeletal features single jaw bone
  • In the original synapsid condition the jaw was
    made up of an anterior tooth-bearing dentary with
    a series of bones (the post-dentary bones)
    forming the posterior half.
  • In this condition the articular bone of the lower
    jaw articulated with the quadrate bone of the
    skull.

20
Skeletal features single jaw bone
  • In later synapsids the cynodonts a process of the
    dentary grew back and eventually made contact
    with the squamosal bone of the skull. earliest
    mammals.
  • This contact eventually formed a new jaw joint
    the dentary-squamosal joint.

21
Skeletal features single jaw bone
  • In the earliest mammals there were two jaw
    joints, but the original joint was eventually
    lost, and the jaw came to consist of a single
    bone the dentary and the post-dentary bones came
    to form part of the middle ear.

22
Evolution of dentary-squamosal joint http//beta.r
evealedsingularity.net/content/articles/mammal_ear
/images/jaw_artic.png
23
Skeletal features three ear bones
  • In modern mammals there are three ear bones the
    incus, malleus and stapes that transmit
    vibrations from the tympanum to the oval window
    of the cochlea.
  • These are derived from the post-dentary bones of
    the synapsid jaw. The use of these bones in
    hearing is not as strange as it seems at first
    because Allin (1975) suggested that these three
    bones always performed this function in synapsids.

24
Endothermy
  • Along with the birds mammals are the only groups
    of endothermic animals.
  • Endothermy allows mammals to occupy some very
    harsh environments, high mountains, the arctic,
    oceans that other amniotes vertebrates do not,
    but it requires the animals to expend a lot of
    energy to maintain an elevated body temperature.

25
Endothermy
  • Fur plays a major role in insulation (and birds
    are similarly insulated with feathers), but it
    water it is a less effective insulator and there
    mammals have turned to blubber as an alternative.

26
Brown fat
  • Mammals also possess a specialized type of
    adipose tissue brown fat that is specially
    adapted to generate heat.
  • Brown fat breaks down lipids and glucose to
    produce heat and can generate as much as 10X as
    much heat as an equivalent mass of muscle.
  • Brown fat is most abundant in newborn mammals
    (that lack fur) and in hibernating mammals that
    use it to rewarm the body quickly at the end of
    hibernation.

27
Cardiovascular system
  • Because of their high metabolic rates, mammals
    must be able to deliver oxygen to the tissues as
    efficiently as possible.
  • As in birds, a four chambered heart has evolved.
    This ensures that the oxygenated and deoxygenated
    blood are kept completely separate and maximizes
    oxygen delivery to the tissues.
  • Again as in birds, the pulmonary and systemic
    circuits are two separate loops.

28
Muscular diaphragm
  • Mammals have large, lobed lungs and these have a
    sponge-like appearance because of the branching
    bronchioles, which end in in blind-chambers
    called alveoli.
  • Mammalian lungs are tidal (unlike bird lungs) and
    so less efficient, but are more efficient than
    reptilian lungs because they possess a diaphragm.
  • The expansion of the rib cage which is sealed at
    the bottom by the diaphragm creates a partial
    vacuum that draws air into the lungs.

29
Sensory systems
  • Mammals have exceptionally large brains and, as a
    group, most depend more heavily on olfaction and
    hearing rather than vision.
  • The dependence on olfaction and hearing is a
    consequence of the fact that for much of their
    evolutionary history mammals were largely
    nocturnal and many species remain so today.
  • A notable exception to this pattern is the
    primates with their diurnal habits. They
    primarily depend on vision.

30
Vision
  • For nocturnal animals visual sensitivity (being
    able to form images in low light) is more
    important than visual acuity (being able to form
    detailed images).
  • Most mammals have retinas filled mainly with rod
    cells, which are very sensitive to light, but
    relatively poor at acute vision.

31
Vision
  • A high quality image can be formed only in the
    all-cone fovea, and these cells also allow color
    vision.
  • Most mammals have either monochromatic or
    dichromatic vision (they possess only one or two
    types of cones respectively).
  • The mammals ancestors had trichromatic vision
    (fish and reptiles have trichromatic vision
    turtles have tetrachromatic) but it it was lost
    in the ancestor of modern placental mammals
    presumably because of their nocturnal habits.
    Marsupials appear to have trichromatic vision.

32
Vision
  • Among placentals some primates have trichromatic
    color vision. However, it was evolved from
    dichromatic ancestors and it apparently happened
    twice independently in the primates in both the
    New World monkeys and the Old World monkeys and
    apes.
  • Trichromatic vision must provide a big advantage
    for these animals, most likely it enables them to
    spot ripe fruit and identify the newest and most
    tender leaves.

33
Modern mammals
  • The modern mammals are derived from the synapsid
    lineage and three lineages diverged in the
    Mesozoic.
  • The three groups can be separated on the basis of
    differences in reproduction
  • These are the
  • Monotremes egg laying platypus, echidna.
  • Marsupials young poorly developed at birth,
    reared in a pouch, kangaroo, possum, wombat,
    koala.
  • Placental young well developed at birth. During
    development sustained by a placenta horse,
    whale, mouse, bat, mole.

34
20.2
35
Diversification of modern mammals
  • After the Cretaceous extinction 65 mya wiped out
    the dinosaurs, mammals radiated to occupy niches
    previously occupied by the dinosaurs.
  • The succeeding era the Cenozoic (65 mya to today)
    is also known as the Age of Mammals.

36
Diversification of modern mammals
  • When the Cenozoic began all mammals were small
    and relatively unspecialized.
  • The marsupials of the time apparently were
    omnivorous and arboreal (like modern opossums),
    whereas the placentals were mostly shrew-like
    terrestrial insectivores.

37
Continental positions
  • In the early Cenozoic the continents were in
    different positions than they are today and
    several were more isolated from each other than
    they are today.
  • Africa separated from South America, Antarctica
    and Australia in the Cretaceous, but South
    America, Antarctica and Australia were still
    connected to each other in the early Cenozoic.
  • Asia and North America were connected and eastern
    North America and Europe also were often
    connected in the early Cenozoic.

38
Continental Positions
  • Obviously since the early Cenozoic continental
    position have changed.
  • India collided with Asia, Africa with southern
    Europe and South America and North America have
    been linked by the Isthmus of Panama. In each
    case, the joining of land masses allowed faunas
    that had evolved in isolation to mingle.
  • Mammalian diversity was thus shaped by a
    combination of diversification in isolation
    followed by later merging of faunas.

39
Continental Positions
  • Major diversification of the mammals occurred at
    the beginning of the Cenozoic.
  • Because early bursts of diversification that gave
    rise to multiple modern groups occurred on
    different isolated continental land masses the
    higher level classification of modern mammals
    reflects the influence of the early Cenozoic
    distribution of land masses.

40
Biogeography of marsupials
  • Marsupials evolved when South America, Australia
    and Antarctica were still connected.
  • When these continents separated, those on
    Antarctica were wiped out eventually by the cold
    climate as the continent drifted south. However,
    the marsupials on Australia and South America
    diversified.
  • Australia remained isolated and marsupials
    diversified there in the absence of placental
    mammals. South America eventually joined to
    North America and placental and marsupial mammals
    came into contact there.

41
Biogeography of placental mammals
  • Two major lineages of placental mammals the
    Afrotheria and Laurasiatheria originated on
    separate land masses in the early Cenozoic.
  • The Afrotheria originated in Africa the
    Laurasiatheria in Laurasia (North America, Asia,
    Europe).

42
Cladistic Classification of the Mammalia after
Lecointre and Le Guyader (2006)
Monotremata
Marsupialia
Mammalia
Xenarthra
Theria
Tubulidentata
Afrosoricida
Macroscelidea
Afrotheria
Hyracoidea
Eutheria
Proboscidea
Sirenia
Dermoptera
Scandentia
Primates
Lagomorpha
Glires
Rodentia
Laurasiatheria
43
Afrotheria
  • Members are
  • Tubulidentata aardvark
  • Afrosoricida otter shrews, tenrecs, golden moles
  • Macroscelidea elephant shrews
  • Hyracoidea hyraxes
  • Proboscidea elephants
  • Sirenia dugongs and manatees

44
Eulipotyphyles
Chiroptera
Laurasiatheria
Perissodacytla
Carnivora
Pholidota
Tylopoda
Suina
Cetartiodactyla
Ruminantia
Hippopotamidae
Cetacea
45
Laurasiatheria
  • Members are
  • Eulipotyphles shrews, moles, hedgehogs
  • Chiroptera bats
  • Perissodactyla Rhinos, horses, tapirs
  • Carnivora cats, dogs, seals, bears, weasels
  • Cetartiodactyla camels, pigs, deer, antelope,
    hippos, whales

46
Biogeography of placental mammals
  • Obviously many members of both the Afrotheria and
    Lausasiatheria have dispersed widely across the
    globe since their origin.
  • For example, elephants and mammoths spread
    throughout Europe, Asia and North America after
    Africa joined Europe.

47
Biogeography of placental mammals
  • In other cases, groups that had diversified on
    their continent of origin were outcompeted when
    other groups arrived.
  • For example hyraxes, which today exist only as
    fairly small rodent-like animals occupied
    ecological roles similar to those of pigs and
    antelopes before Africa joined Eurasia.
  • Similarly, before South America joined North
    America the large carnivores were the now extinct
    borhyaenoid marsupials. Both groups were
    outcompeted by competitors from the north.

48
Borhyaena http//scienceblogs.com/tetrapodzoology
/Borhyaena20from20Argot202003.jpg
49
Rock Hyrax http//www.marietta.edu/biol/biomes/im
ages/desert/rock_hyrax_7042.jpg
50
Classification of Modern mammals
  • There are only about 4800 living species of
    mammals so the group is not very species diverse,
    but it does include the largest living
    terrestrial (elephants) and aquatic animals
    (whales) and there is a great deal of
    morphological diversity.
  • The mammals can be divided into three major
    lineages on the basis of differences in
    reproduction
  • Monotremes
  • Marsupials
  • Placental mammals

51
20.2
52
Classification of modern mammals
  • The marsupial and placental mammals are united
    into a group the Theria because they share a
    multiple traits that monotremes lack.
  • Give birth to live young
  • Nipples
  • Cochlea with at least 2.5 turns
  • External ear
  • Lack of an interclavicle bone

53
Cladistic Classification of the Mammalia after
Lecointre and Le Guyader (2006)
Monotremata
Marsupialia
Mammalia
Xenarthra
Theria
Tubulidentata
Afrosoricida
Macroscelidea
Afrotheria
Hyracoidea
Eutheria
Proboscidea
Sirenia
Dermoptera
Scandentia
Primates
Lagomorpha
Glires
Rodentia
Laurasiatheria
54
Monotremes
  • The monotremes are a small order of four species
    the duck-billed platypus and three species of
    spiny anteater or echidna found in Australia and
    New Guinea. They diverged from the lineage
    leading to the other mammals in the Jurassic
    period about 180 mya.
  • Monotremes have several reptilian traits
  • Monotreme means single hole in Greek and refers
    to the fact that the anus, urinary tract and
    reproductive tract all empty into a single
    opening the cloaca, as is the case in lizards and
    birds.

55
Monotremes
  • In addition, the monotremes lay eggs with a tough
    leathery shell and possess an interclavicle bone,
    one found in reptiles, but not in other mammals.
  • However, they clearly are mammals possessing a
    single dentary, three ear bones, hair, and milk
    although they lack nipples and the milk seeps
    from pores over a relatively wide area.

56
Platypus
  • When specimens of the platypus first arrived in
    Europe they were thought to be a hoax with their
    strange combination of fur and a duck-like bill.
  • The platypus bill is a highly sensitive organ
    that detects faint electrical fields.
  • When hunting underwater the platypus sweeps the
    bill from side to side and the input is processed
    in the brain, a very large proportion of which is
    devoted to analyzing information from the bill.
    The electrical input enables the platypus to zero
    in on buried prey in the sediment.

57
Platypus http//www.itsnature.org/wp-content/galle
ry/platypus-and-echidna/platypus.jpeg
58
Echidnas
  • Echidnas are terrestrial, covered in spines and
    eat ants and termites. They have a tubular bill.
  • A fossil platypus, Obduradon, is known that is
    older than the most recent common ancestor of
    echidnas and platypuses, which means echidnas
    evolved from a platypus ancestor.

59
Echidna
60
Marsupials
  • There are seven orders of marsupials with about
    275 species that include such animals as possums,
    kangaroos, wombats, koalas and Tasmanian devils.
  • All marsupials have an abdominal pouch in which
    the young are raised having been born very
    underdeveloped, moving to the pouch and latching
    onto a nipple.

61
20.18
62
Marsupials
  • The greatest diversity of marsupials occurs in
    Australia where the largest grazers and
    carnivores occur, but a wide variety of opossums
    occur in Central and South America.
  • The living marsupials are split into two groups
    the Ameridelphia of the New World and the
    Australidephia of (mainly) Australia.

63
Ameridelphids
  • There are two orders of Ameridelphids.
  • Didelphimorphia About 77 species including the
    North American Opossum. The South American
    opossums are small to medium sized, omnivorous
    and mainly arboreal. Includes the otter-like
    Yapok, which catches fish.
  • Paucituberculata Five species of rat opossums.
    This was a much more diverse group in the past
    and included the carnivorous, doglike Borhyaenoids

64
Yapok http//www.bbc.co.uk/nature/wildfacts/factfi
les/picpops/images/yapok02.jpg
65
Rat opossum http//www.mammalogy.org/mil_images/im
ages/mid/625.jpg
66
Australidelphia
  • These all occur in Australia with the exception
    of one species that occurs in South America, the
    mouselike monito-del-monte.
  • The monito-del-monte is the sole living member of
    the Microbiotheriidae, a family that was believed
    to have been extinct for more than 20 million
    years. It occurs in montane forests in Chile and
    Argentina.

67
Monito-del-monte http//www.smh.com.au/ffximage/20
08/03/27/470_marsupial,0.jpg
68
Australidelphia
  • The monito-del-monte is considered to be a relict
    member of the ancestral stock of marsupials that
    migrated to Australia in the early Cenozoic.

69
Australidelphia
  • The other orders of the Australidelphia are the
  • Dasyuromorphia Tasmanian devil, numbat,
    marsupial mice. Three families, 60 species.
  • Notoryctemorphia marsupial mole. 1 species.
  • Peramelina bandicoots and bilbies. Two families,
    21 species.
  • Diprotodontia possums, flying phalangers,
    koalas, wombat, kangaroos, wallabies, honey
    possum. Nine families, 110 species.

70
Dasyuromorphia
  • The dasyurids are carnivorous. The marsupial
    mice (more shrew-like than mouse-like) are
    insectivorous.
  • The Tasmanian devil is larger (8-12kg), doglike
    and mainly a scavenger. It is found only on
    Tasmania having become extinct on mainland
    Australia after the introduction of dingoes.
    They have powerful jaws and teeth and consume all
    parts of the carcass, bones and hide.
  • In recent years numbers have declined as result
    of Devil facial tumor disease. It is a
    transmissable cancer that is spread through bites

71
Marsupial mouse http//narooma.yourguide.com.au/ m
ultimedia/images/full/178450.jpg
Tasmanian devil http//yadogg.com/wp-content/uploa
ds/2007/08/tasmanian-devil.jpg
72
Thylacine
  • The Tasmanian wolf (thylacine) is extinct. It
    was a large wolf-like marsupial with a
    distinctive striped back and a spectacularly wide
    gape.

73
Thylacine http//www.thedudeclub.com/wp-content/up
loads/2008/05/thylacine.jpg
http//www.oddee.com/_media/imgs/articles/a98_Thyl
acine.jpg
74
Notoryctemorphia
  • Includes only one species the marsupial mole.
  • The marsupial mole is very similar in appearance
    to the true moles (Eulipotyphles) and the golden
    moles (Afrosoricida). Marsupial moles have
    spades modified out of two claws and like the
    other moles dig tunnels and feed on worms and
    insects.
  • All three groups are blind, have no visible ears
    and short or absent tails and are a great example
    of convergent evolution.

75
Marsupial mole
http//farm3.static.flickr.com/2315/ 1518610598_3e
fd7ceed8.jpg?v0
http//www.nma.gov.au/shared/libraries/images/ tem
porary_exhibitions/extremes/extremes_large/austral
ia/ marsupial_mole_tanami_desert_australia/files/6
385/ nma.img-___TE02396-000-vi-vs1.jpg
76
Peramelina
  • This group consists of the bandicoots and
    bilbies. Some of them have long ears, which makes
    them look a bit Iike rabbits but they are
    insectivores.
  • Peramelids have the 2nd and 3rd toes of the hind
    foot reduced in size and enclosed in a layer of
    skin to form what looks like a single toe. This
    syndactylous toe is used for grooming. It is
    also found in the diprotodontians.

77
Bandicoot http//www.chocolateginger.com/bandicoot
.jpg
78
Diprotodontia
  • This is the largest group of marsupials. They
    are called diprotodontians because all of them
    possess lower incisors that have been modified
    into forward projecting, somewhat rodent-like
    teeth.

79
Diprotodontia
  • There are three major groupings within the
    diprotodontians
  • Six families of smaller arboreal species
    including possums, cuscuses and several gliding
    phalangers including the sugar glider.
  • Vombatiformes which includes the terrestrial
    wombats and arboreal koalas.
  • Macropodoids which includes the small omnivorous
    rat kangaroos and the bigger, herbivorous true
    kangaroos and wallabies.

80
http//www.convictcreations.com/ animals/images/su
gargliger.jpg
Sugar gliderhttp//www.cartage.org.lb/en/themes/sc
iences/zoology/ClassMammalia/ Mammals/OrderDiproto
dontia/SugarGlider/sugarglider.jpg
81
Brush-tailed phalanger http//www.naturephoto-cz.c
om/photos/ others/brush-tailed-phalanger-62285.jpg
Spotted Cuscus http//members.optusnet.com.au/7Ea
lreadman/cuscus120hjb.jpg
82
Koalas http//www.southernmamas.com/wp-content/up
loads/2008/01/koala_baby.jpg
83
Southern hairy-nose wombat https//secure7.ozhosti
ng.com/cws/ graphics/popups/wildlife_ mammals_Sout
hern_hairy_nose _wombat2.jpg
Wombat http//www.quantum-conservation.org/EEP/WO
MBAT.jpg
84
Rock Wallaby
85
Eutherian mammals
  • The Eutherian or placental mammals support their
    developing young using a chorioallantoic
    placenta which brings the blood supplies of
    mother and offspring into close contact so that
    food and gases can be effectively exchanged.

86
Cladistic Classification of the Mammalia after
Lecointre and Le Guyader (2006)
Monotremata
Marsupialia
Mammalia
Xenarthra
Theria
Tubulidentata
Afrosoricida
Macroscelidea
Afrotheria
Hyracoidea
Eutheria
Proboscidea
Sirenia
Dermoptera
Scandentia
Primates
Lagomorpha
Glires
Rodentia
Laurasiatheria
87
Eulipotyphyles
Chiroptera
Laurasiatheria
Perissodacytla
Carnivora
Pholidota
Tylopoda
Suina
Cetartiodactyla
Ruminantia
Hippopotamidae
Cetacea
88
Xenarthra
  • Thirty species of armadillos, sloths and
    anteaters. They are widespread in South and
    central America and one species the nine-banded
    armadillo occurs in the southern United States.
  • They are either toothless (anteaters) or have
    simple peg-like teeth. All have strong claws
    that they use for digging, ripping open termite
    mounds or to hang suspended in trees (sloths)

89
Pink fairy armadillo http//gallery.nen.gov.uk/ ga
llery_images/0709/0000/0267/ pink_fairy_armadillo_
mid.jpg
Giant Anteater http//www.junglewalk.com/ animal-p
ictures/622/ Giant-anteater-4059.jpg
90
Afrotheria
  • The group includes a set of species that
    originated in Africa some of which later
    dispersed more widely.
  • Members are
  • Tubulidentata aardvark
  • Afrosoricida otter shrews, tenrecs, golden moles
  • Macroscelidea elephant shrews
  • Hyracoidea hyraxes
  • Proboscidea elephants
  • Sirenia dugongs and manatees

91
Tubulidentata
  • The Tubulidentata has only one species the
    aardvark, which occurs in Africa.
  • It is nocturnal, pig-size, and feeds on termites
    and ants. It rips its way into termite mounds
    using its powerful claws.
  • Its teeth are unusual (hence the name
    Tubulidentata). They lack enamel and instead of
    a single pulp cavity, each tooth has several
    upright parallel tubes of vasodentin (a modified
    dentin) each of which has its own pulp canal.

92
Aardvark http//animals.nationalgeographic.com/st
aticfiles/NGS/ Shared/StaticFiles/animals/images/p
rimary/aardvark.jpg
93
Afrosoricida
  • Historically the members of the Afrosoricida were
    part of a polyphyletic group called the
    Insectivora.
  • This was a hodge-podge of small mammals that ate
    insects and as well as the Afrosoricids included
    among others the elephant shrews, tree shrews,
    and true shrews all of which are now included in
    different groups.

94
Afrosoricida
  • Otter shrews, tenrecs, golden moles.
  • All originated in Africa and all are small
    animals with dense fur, small eyes and short
    powerful legs.
  • Tenrecs occur only on Madagascar and they have
    spines scattered through the fur or just spines.
  • Otter shrews look like small otters with
    elongated bodies. They have a valve of tissue
    that seals off the nostrils when diving.
  • Golden moles resemble marsupial moles and talpid
    moles and the front paws have two strong claws
    used for digging.

95
Giant Otter shrew http//cas.bellarmine.edu/tietje
n/RootWeb/Insectivora.jpg
96
Streaked tenrec http//media-2.web.britannica.com/
eb-media/75/22175-004-92ADC9E4.jpg
Hedgehog tenrec http//animaldiversity.ummz.umich.
edu/ site/resources/mzm2/46.mr2.jpg/medium.jpg
97
Cape Golden mole http//www.biodiversityexplorer.o
rg/mammals/afrosoricida/images/eos03241_663x498.jp
g
98
Macroscelidea
  • Elephant shrews or sengis are found only in
    Africa and there are 16 species. They eat
    invertebrates fruits and seeds.
  • They are small weighing from 2 ounces to a pound.
    They have long legs, which make them swift
    runners and have long, mobile elephant-like
    noses. In their home range they maintain a
    network of paths along which they run quickly to
    escape predators.

99
Black and rufous Elephant shrews http//www.peabo
dy.yale.edu/exhibits/treeoflife/images /black_and_
rufous_elephant_shrews.jpg
100
Hyracoidea
  • Hyraxes are small, tailless and stocky and weigh
    2.5-3.5 kg. They look a bit like groundhogs.
  • Found in Africa and the Middle East, hyraxes are
    surprisingly good climbers and some are arboreal.
    Others are found on rock outcroppings.
  • They have elastic pads on their feet, which they
    moisten with sweat to help them grip when
    climbing.
  • Like rodents, hyraxes have continuously growing
    incisors and lack canines. There is gap between
    incisors and premolars (called a diastema).

101
Rock Hyrax http//www.ucmp.berkeley.edu/mammal/me
saxonia/hyrax.jpg
102
Proboscidea
  • Elephants. The largest terrestrial mammals they
    weigh up to 6 tons.
  • There are two living species the African and
    Asian elephants, although African forest and
    savannah elephants are genetically distinct and
    there are at least 4 subspecies of Asian
    elephant.
  • They lack lower canines and the third upper
    incisors have been modified into tusks and the
    nose and upper lip into the characteristic trunk.

103
Proboscidea
  • Elephants are dominant herbivores and occur in a
    wide variety of habitats from savannah to
    mountain forest (up to 5,000 m).
  • They live in matriarchal family groups and
    maintain close family bonds throughout their
    lives.
  • Elephants range widely in search of food. They
    require 100-200kg of vegetation daily and can be
    very destructive of vegetation and frequently
    come into conflict with humans when they raid
    crops.

104
African Elephant http//myanimalblog.files.wordpre
ss.com/ 2008/02/elephant.jpg
Asian Elephant http//www.naturephoto-cz.com/ph
otos/sevcik/asian-elephant--elephas-maximus-1.jpg
105
Sirenia
  • The sirenians consist of five species of dugongs
    and manatees, which are large aquatic grazing
    mammals that typically occur in large family
    groups.
  • They have no hind limbs and the forelimbs have
    been modified into swimming paddles. They are
    slow-moving and dont dive actively and sink by
    regulating the amount of air in their lungs.

106
Sirenia
  • Manatees and dugongs differ in the shape of their
    tails (its bifurcated in dugongs).
  • All living species are found in rivers, and
    coastal waters in warm seas and are endangered as
    a result of habitat destruction, pollution and
    conflict with humans. One species, Stellers sea
    cow, was hunted into extinction in 1768, only 27
    years after it was discovered.

107
Dugong http//www.unep.org/dewa/images/ dugong-cov
erpic-for-web.jpg
Manatee http//www.goddardscuba.com/ Schedule/2008
/manatee.jpg
108
Dermoptera
  • There are two species of colugos (or flying
    lemurs) one found in the Philippines and the
    other in Java and Borneo.
  • They have an extensive gliding membrane that
    stretches between the limbs and from the hind
    limbs to the tail.
  • They can glide up to 150m at a time and feed on
    fruits, leaves and flowers.
  • http//www.eurekalert.org/ images/kidsnews/janecka
    3LR.jpg
  • Colugo http//www.americazoo.com/goto/index/mammal
    s/dermoptera.htm

109
Scandentia
  • Tree Shrews (19 species) are small arboreal
    mammals that are quite squirrel like in
    appearance.
  • They are diurnal animals that live in the trees
    and underbrush in forests in southeast Asia.
  • They have primate-like brain and skull anatomy as
    well as almost opposable toes. However, the
    dentition is insectivorous.
  • Various taxonomists have over the years grouped
    the tree shrews with insectivores, rodents,
    lagomorphs, primates and even marsupials. The
    current placement as sister group to the primates
    is based on gene sequence data.

110
Tree shrew http//www.ryanphotographic.com/images
/JPEGS/Tree20shrew.jpg
111
Primates
  • Tarsiers, lorises, bush babies, lemurs, New World
    and Old World monkeys, gibbons, apes, humans.
  • Primates have opposable thumbs and opposable big
    toes, which allows both hands and feet to grip
    branches.
  • Orbits are forward facing for binocular vision.
    The brain is well developed in many groups and
    they are often highly social.

112
Lorisiformes
Strepsirrhini
Lemuriformes
Primates
Tarsiformes
Platyrrhini
Cercopithecoidea
Hylobatoidae
Hominoidea
Pongidae
Hominoidae
Gorillinae
Hominidae
Homini
Homininae
Panini
Classification of the Primates after Lecointre
and Le Goyader (2006)
113
Lorisiformes
  • The lorises and lemurs are members of the
    strepsirrhini and they share a characteristic
    dental comb of four incisors and two
    forward-projecting canines . This is used to
    strip vegetable material (e.g. tree gum) when
    feeding and in grooming.
  • Lorisiformes (10 species of lorises and bush
    babies) are small, large-eyed (200-300 g)
    nocturnal, arboreal primates with round heads.
  • They occur in Africa, India and southeast Asia
    and are omnivorous eating insects, fruits and
    tree gum.

114
Lorisiformes
  • Lorises (including the potto) are chameleon-like
    and slow moving. They cant jump and depend on
    camouflage and immobility for protection.
  • The six species of bush baby (or galago) are much
    more agile and active and run and jump to hunt
    and to escape predators.

115
Slow Loris http//www.sfgate.com/n/pictures/2006/0
6/14/loris.jpg
Potto http//www.dumondconservancy. org/dc2005/ima
ges/web/primate 20pics/Prosimians/Loridae/ Potto
201.jpg
Bush baby http//www.hlasek.com/foto/otolemur_cras
sicaudatus_ db9035.jpg
116
Lemuriformes
  • There are 22 species of lemur and they occur only
    on Madagascar where they evolved in isolation
    from competition with monkeys.
  • They range is size from the mouse-lemurs (5
    inches long excluding the tail and 55 g) to the
    indri (up to 70cm and 10kg). They include the
    familiar ring-tailed lemur and the bizarre
    aye-aye.
  • Lemurs are arboreal, but do not brachiate.
    Instead they jump vertically from branch to
    branch.

117
Mouse lemur http//animals.nationalgeographic.com/
staticfiles/NGS/ Shared/StaticFiles/animals/images
/primary/mouse-lemur.jpg
Indri http//www.bushhouse-madagascar.com/ images
/indri_indri_madagascar01.jpg
Ring-tailed Lemur http//www.erikvp.com/Images09/r
ing-tailed-lemur.jpg
118
Lemuriformes aye-aye
  • The aye-aye is a solitary nocturnal species that
    eats fruit and insect larvae, which it digs out
    of wood using powerful forward projecting
    incisors.
  • It has large ears, which it uses to detect insect
    larvae and a greatly elongated, very thin, third
    finger, which it uses to winkle the larvae out of
    their holes.

119
Aye-aye http//animals.nationalgeographic.com/ st
aticfiles/NGS/Shared/StaticFiles/animals/ images/p
rimary/ayeaye.jpg
Aye-aye hand http//alphabeticaprime.files.wordpre
ss.com/2008/02/aye-aye_hand.jpg
120
Lemuriformes
  • All lemurs are threatened by habitat destruction
    as Madagascars human population has boomed and
    large areas of natural habitat have been
    converted into farmland or cut for lumber.
  • Fourteen species of lemur have become extinct
    since humans arrived on Madagascar about 2000
    years ago including some that were as big as
    orang-utans.

121
Tarsiiformes
  • Three species of tarsier and all are small and
    arboreal with greatly enlarged orbits.
  • They have long hindlimbs and are excellent
    jumpers.
  • They are nocturnal and fed on insects and small
    vertebrates.
  • Found on islands in southeast Asia.

Tarsier http//blog.makezine.com/_wp- content_upl
oads_2007_08_tarsier.jpg
122
Platyrrhini
  • The Platyrrhini are 51 species of New World
    monkeys and include two main groups the
    callithricids marmosets and tamarins and the
    cebids capuchins, squirrel monkeys and howler
    monkeys.
  • They live in tropical rain forests and other
    forests and possess a prehensile tail which they
    can use to grip branches when climbing.

123
Platyrrhini
  • Marmosets and tamarins are small 150-700 g)
    colorful monkeys that often have mustaches or
    manes of hair. Their nails have been modified
    into claws.
  • They live in monogamous family groups.

Tufted eared marmoset http//cache.virtualtourist.
com/ 3862569-Tufted_ear_marmoset- Estado_da_Bahia.
jpg
124
Platyrrhini
  • The cebids eat fruits, leaves, seeds, insects and
    small vertebrates and social organization ranges
    from monogamous pairs to large polygamous groups.
    One species, the northern night monkey, is
    nocturnal

Red Howler monkey
Spider monkey http//www.aguilaharpia.org/photos3/
Panama-Spider-Monkey-3.jpg
125
Cercopithecoidea
  • The Old World monkeys includes 82 Afro-Asiatic
    species that include two main groups the large
    bodied, mostly terrestrial baboons and macaques
    (cercopithinae) and the smaller, more delicately
    built vervets, colobuses, and langurs
    (colobinae).
  • Most species eat fruit and leaves, but baboons
    frequently hunt hares and young gazelles. All
    Old World monkeys possess a tail, but it is not
    prehensile.

126
Black and white colobus http//www.game-reserve.co
m/images/wildlife /primates_other/guereza_colobus_
monkey_02.jpg
Baboons http//www.animalwebguide.com/Baboon-2.jpg
127
Hylobatoidae
  • These are the nine species of gibbons and
    siamangs, which are slender, tailess apes with
    very long arms and a highly flexible wrist, which
    allows them to brachiate. They move awkwardly on
    the ground.
  • They live in family groups in the tropical
    forests of southeast Asia and feed almost
    entirely on fruit.

Hoolock Gibbon http//www.pittsburghzoo.org/uploa
d/Image/hoolock-gibbon.jpg
128
The Great Apes
  • The five species of great apes are the
    orang-utan, gorilla, chimpanzee, bonobo and
    human.
  • All are large with a highly folded cerebral
    cortex in the brain and all lack tails.

129
Pongidae
  • The orang utan is the sole member of the Pongidae
    and they inhabit the tropical rain forest of
    southeast Asia.
  • Orangs are solitary the only great ape that spend
    almost all of its time in the trees. They are
    excellent brachiators.
  • The diet consists largely of fruit and leaves
    occasionally supplement with insects, eggs and
    small vertebrates.
  • They are greatly threatened by loss of rainforest
    habitat in Borneo and Sumatra.

130
Orang Utan http//naturescrusaders.files.wordpress
.com/2009/04/orangutan-male.jpg
131
Gorillinae
  • Gorillas are the largest living primate and live
    in small family groups led by a single dominant
    male. They are terrestrial during the day but
    sleep in trees at night.
  • They are vegetarians and occur in the lowland
    forests of west Africa and mountain forests in
    Rwanda and eastern Congo.
  • They are threatened by poaching and deforestation.

132
Panini
  • Two species the chimpanzee and bonobo.
  • They live in bands of 10-30 individuals. Most of
    the diet is vegetarian, but chimps will hunt and
    kill baby antelopes, pigs and small monkeys.
  • Occur in central and western Africa.

133
http//phineasgage.files.wordpress. com/2007/06/07
0617chimp.jpg
http//www.awf.org/files/3972_image2_western_goril
la_MWatson.jpg
134
Homini
  • Humans largely hairless great ape.
  • Posesses advanced reasoning and communication
    capabilities and a high degree of technological
    sophistication.
  • Highly social. Widespread.

135
Glires Lagomorpha
  • The lagomorphs consist of about 80 species of
    rabbits, hares and pikas. Strictly vegetarian
    they have a well developed cecum to facilitate
    digestion of vegetation.
  • Rabbits and hares have long legs and are fast
    runners. They also have long ears (especially in
    species from hot regions).
  • Pikas are primarily found in mountainous, alpine
    terrain.
  • They were once grouped with the rodents as they
    also have prominent incisors used for gnawing.
    However, they have two pairs of incisors in the
    front of the mouth (the 2nd pair are vestigial
    and located behind the first).

136
Pika http//media-2.web.britannica.com/eb-media/16
/3516-004-67E3395A.jpg
137
Glires Rodentia
  • Rodentia Rodents. The largest group of mammals
    with more than 2000 distributed worldwide.
  • Includes more than 1,300 species of rats and mice
    as well as squirrels, mole rats, woodchucks,
    beavers, gerbils, lemmings, capybaras, and
    agoutis.

138
Rodents
  • The key to their success is their chisel like
    upper and lower incisors that grow continuously.
  • The front of the tooth has a thick layer of
    enamel but the rear has a layer of dentine that
    is much softer.
  • The movement of the upper and lower incisors
    against each other wears down the dentine and
    leaves a very sharp chiseled edge that enables
    the rodents to open even the hardest seeds. To
    assist in their chewing the rodents also have
    highly enlarged masseter muscles.

139
Beaver teeth http//www.arkive.org/media/ 20/20646
7D2-694F-4269-BFBC- 9925111529EE/Presentation. Lar
ge/photo.jpg
http//www.usefilm.com/images/ 4/8/6/8/4868/124626
9-medium.jpg
140
Rodents
  • Various species of rats and mice have spread
    across the globe as commensals with humans. They
    are enormous pests of stored foods especially
    grains and almost certainly there are more
    rodents on earth than all other mammals combined.
  • They also are major vectors of disease such as
    typhus and bubonic plague. In the past 1,000
    years rodent spread diseases have probably been
    responsible for more humans deaths than all wars
    combined have caused.

141
Cladistic Classification of the Mammalia after
Lecointre and Le Guyader (2006)
Monotremata
Marsupialia
Mammalia
Xenarthra
Theria
Tubulidentata
Afrosoricida
Macroscelidea
Afrotheria
Hyracoidea
Eutheria
Proboscidea
Sirenia
Dermoptera
Scandentia
Primates
Lagomorpha
Glires
Rodentia
Laurasiatheria
142
Eulipotyphyles
Chiroptera
Laurasiatheria
Perissodacytla
Carnivora
Pholidota
Tylopoda
Suina
Cetartiodactyla
Ruminantia
Hippopotamidae
Cetacea
143
Eulipotyphyles (insectivores)
  • This group of almost 300 species includes much of
    what was historically included in the
    insectivores, desmens, shrews, moles,
    hedgehogs, and solenodons.
  • They are small to very small (the pygmy
    white-toothed shrew at 2g is the worlds smallest
    mammal).
  • Highly active with very high energy needs, mostly
    terrestrial insect eaters and occur worldwide.
  • Generally the senses of smell and hearing are
    most important and they tend to be solitary and
    aggressive.
  • Both moles and hedgehogs have ecological
    equivalents in other groups, the result of
    convergent evolution.

144
20.28
145
Chiroptera
  • Bats. Nocturnal flying mammals with forelimbs
    modified into wings. The flight membrane is
    stretched between long fingers (the metacarpals
    are enormously elongated).
  • Many species use echolocation. About 925 species,
    second only in size to Rodentia.
  • There are two major groups the large
    megachiroptera (the fruit bats) which have
    long-muzzled fox-like faces and mainly eat fruit
    and the microchiroptera which have flattened
    faces, small eyes and large ears.

146
http//fireflyforest.net/images/firefly/2007/ Febr
uary/Lesser-Long-nosed-Bat-1.jpg
Epauletted fruit bat http//www.taos-telecommunity
.org/epow/ EPOW-Archive/archive_2008/ EPOW-080317_
files/ P116066320wahlbergs20epauletted20fruit2
0bat_s.jpg
147
Perissodactyla
  • Odd-toed ungulates. Horses, zebras, asses,
    tapirs, rhinoceroses. 18 species. They have a
    long muzzle with strong prehensile lips.
  • The main supporting axis of the hind limbs passes
    through the third toe.
  • Horses donkeys and zebras have a single toe,
    rhinos and tapirs have three toes on the hind
    feet, but tapirs have 4 on the forefeet (but the
    third toe is the strongest)
  • All herbivorous with teeth adapted to chewing
    vegetation. The caecum in the intestines
    (analagous to the rumen in ruminants) is enlarged
    and anaerobic fermentation of cellulose by
    bacteria takes place there.

148
20.32
149
Carnivora
  • Medium to large flesh-eaters. Cats, dogs,
    weasels, badgers, mongooses, racoons, bears,
    seals, sealions. 271 species.
  • Teeth specialized for killing. Canines are long
    and pointed and molars have numerous slicing
    cusps for shearing meat.
  • The last upper premolar and first lower molar are
    modified into carnassial teeth that work like
    scissors to cut meat away from bones.

150
http//www.cartage.org.lb/en/themes/sciences/zoolo
gy/ Animalclassification/OrderPrimates/carnassials
.jpg
151
Pholidota
  • Pangolins. Seven species of scale covered
    anteaters with powerful claws. They lack teeth
    and have a tube-like snout with a very long
    tongue (up to 16 long).
  • They are mainly nocturnal and are found in
    Africa, India and southeast Asia.
  • To escape predators they curl into a ball so
    tightly that a man cannot unroll them.

http//www.vulkaner.no/n/africa/ somalia/pangolin.
jpg
152
Cetartiodactyla
  • Traditionally, the members of this group were
    classified as two groups the Artiodactyla
    even-toed ungulates pigs, deer, cattle,
    antelopes, hippopotamuses and the Cetacea whales
    and dolphins.
  • Recently, it has become clear that the cetaceans
    are embedded within the Artiodactyla and evolved
    from hoofed predators called mesonychids.
  • Cetaceans are more closely related to hippos than
    hippos are to the other members of the
    Artiodactyla. As a result, the Cetartiodactyla
    has been created.

153
Traditional Articdactyls
  • There are four groups in the Cetartiodactyla that
    would have been included within the previous
    Artiodactyla.
  • Tylopoda Camels and vicunas. 6 species.
  • Suina pigs, warthogs, peccaries. 19 species.
  • Ruminantia Deer, bison, cattle, antelope. 191
    species.
  • Hippopotomidae Hippos 2 species.
  • Two or four toes sheathed in hoofs. Most are
    ruminants and possess multi-chambered stomachs.

154
Eulipotyphyles
Chiroptera
Laurasiatheria
Perissodacytla
Carnivora
Pholidota
Tylopoda
Suina
Cetartiodactyla
Ruminantia
Hippopotamidae
Cetacea
155
20.32
156
Cetacea
  • Whales and dolphins. Aquatic diving mammals.
    Anterior limbs modified into flippers, posterior
    limbs absent, possess large rear fluke for
    propulsion, nostrils modified into blowhole on
    top of head. 78 species.

157
Cetacea
  • The two basic divisions of the cetaceans are the
    toothed whales (Odontoceti) and the baleen whales
    (Mysticeti).
  • Toothed whales (e.g. sperm whale, killer whale,
    dolphins) have homodont dentition. The teeth are
    used to capture prey, but not for chewing.
  • Baleen whales (e.g., blue whale, humpback whale,
    sei whale) feed on smaller prey that they filter
    using their baleen, which is made of keratinized
    extensions of the epidermis. Baleen whales take
    in a mouthful of water and press their tongue
    against the baleen to squeeze out the water and
    then swallow the food trapped inside the mouth.

158
Humpback whale
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