Title: Modern Mammals
1Modern 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
2Lactation
- 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.
3Lactation
- 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.
4Hair
- 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.
5Snow leopard http//metastwnsh.files.wordpress.com
/2008/11/calculation-snow-leopard1.jpg
6Hair
- 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.
7Hair
- 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.
8Hair
- 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.
9Molting mountain goat http//ecolibrary.cs.brandei
s.edu/images/ thumb50/thumb50_Mountain_goat_moltin
g_DP4102.jpg
10Hair
- 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.
11Vibrissae
- 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.
12Cats vibrissae http//upload.wikimedia.org/wikipe
dia/commons/3/39/Cats_whiskers.jpg
13Claws, 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
14http//osnhc.com/images/BASICHOOFANATOMY.jpg
15Horns
- 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.
16White Rhinoceros http//www.mth.msu.edu/peller/Af
rica_large/rhinoceros.jpg
17Skeletal 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.
18Skeletal 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.
19Skeletal 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.
20Skeletal 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.
21Skeletal 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.
22Evolution of dentary-squamosal joint http//beta.r
evealedsingularity.net/content/articles/mammal_ear
/images/jaw_artic.png
23Skeletal 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.
24Endothermy
- 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.
25Endothermy
- 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.
26Brown 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.
27Cardiovascular 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.
28Muscular 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.
29Sensory 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.
30Vision
- 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.
31Vision
- 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.
32Vision
- 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.
33Modern 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.
3420.2
35Diversification 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.
36Diversification 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.
37Continental 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.
38Continental 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.
39Continental 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.
40Biogeography 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.
41Biogeography 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).
42Cladistic 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
43Afrotheria
- Members are
- Tubulidentata aardvark
- Afrosoricida otter shrews, tenrecs, golden moles
- Macroscelidea elephant shrews
- Hyracoidea hyraxes
- Proboscidea elephants
- Sirenia dugongs and manatees
44Eulipotyphyles
Chiroptera
Laurasiatheria
Perissodacytla
Carnivora
Pholidota
Tylopoda
Suina
Cetartiodactyla
Ruminantia
Hippopotamidae
Cetacea
45Laurasiatheria
- 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
46Biogeography 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.
47Biogeography 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.
48Borhyaena http//scienceblogs.com/tetrapodzoology
/Borhyaena20from20Argot202003.jpg
49Rock Hyrax http//www.marietta.edu/biol/biomes/im
ages/desert/rock_hyrax_7042.jpg
50Classification 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
5120.2
52Classification 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
53Cladistic 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
54Monotremes
- 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.
55Monotremes
- 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.
56Platypus
- 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.
57Platypus http//www.itsnature.org/wp-content/galle
ry/platypus-and-echidna/platypus.jpeg
58Echidnas
- 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.
59Echidna
60Marsupials
- 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.
6120.18
62Marsupials
- 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.
63Ameridelphids
- 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
64Yapok http//www.bbc.co.uk/nature/wildfacts/factfi
les/picpops/images/yapok02.jpg
65Rat opossum http//www.mammalogy.org/mil_images/im
ages/mid/625.jpg
66Australidelphia
- 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.
67Monito-del-monte http//www.smh.com.au/ffximage/20
08/03/27/470_marsupial,0.jpg
68Australidelphia
- 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.
69Australidelphia
- 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.
70Dasyuromorphia
- 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
71Marsupial 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
72Thylacine
- The Tasmanian wolf (thylacine) is extinct. It
was a large wolf-like marsupial with a
distinctive striped back and a spectacularly wide
gape.
73Thylacine http//www.thedudeclub.com/wp-content/up
loads/2008/05/thylacine.jpg
http//www.oddee.com/_media/imgs/articles/a98_Thyl
acine.jpg
74Notoryctemorphia
- 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.
75Marsupial 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
76Peramelina
- 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.
77Bandicoot http//www.chocolateginger.com/bandicoot
.jpg
78Diprotodontia
- 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.
79Diprotodontia
- 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.
80http//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
81Brush-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
82Koalas http//www.southernmamas.com/wp-content/up
loads/2008/01/koala_baby.jpg
83Southern 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
84Rock Wallaby
85Eutherian 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.
86Cladistic 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
87Eulipotyphyles
Chiroptera
Laurasiatheria
Perissodacytla
Carnivora
Pholidota
Tylopoda
Suina
Cetartiodactyla
Ruminantia
Hippopotamidae
Cetacea
88Xenarthra
- 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)
89Pink 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
90Afrotheria
- 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
91Tubulidentata
- 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.
92Aardvark http//animals.nationalgeographic.com/st
aticfiles/NGS/ Shared/StaticFiles/animals/images/p
rimary/aardvark.jpg
93Afrosoricida
- 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.
94Afrosoricida
- 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.
95Giant Otter shrew http//cas.bellarmine.edu/tietje
n/RootWeb/Insectivora.jpg
96Streaked 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
97Cape Golden mole http//www.biodiversityexplorer.o
rg/mammals/afrosoricida/images/eos03241_663x498.jp
g
98Macroscelidea
- 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.
99Black and rufous Elephant shrews http//www.peabo
dy.yale.edu/exhibits/treeoflife/images /black_and_
rufous_elephant_shrews.jpg
100Hyracoidea
- 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).
101Rock Hyrax http//www.ucmp.berkeley.edu/mammal/me
saxonia/hyrax.jpg
102Proboscidea
- 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.
103Proboscidea
- 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.
104African 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
105Sirenia
- 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.
106Sirenia
- 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.
107Dugong http//www.unep.org/dewa/images/ dugong-cov
erpic-for-web.jpg
Manatee http//www.goddardscuba.com/ Schedule/2008
/manatee.jpg
108Dermoptera
- 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
109Scandentia
- 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.
110Tree shrew http//www.ryanphotographic.com/images
/JPEGS/Tree20shrew.jpg
111Primates
- 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.
112Lorisiformes
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)
113Lorisiformes
- 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.
114Lorisiformes
- 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.
115Slow 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
116Lemuriformes
- 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.
117Mouse 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
118Lemuriformes 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.
119Aye-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
120Lemuriformes
- 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.
121Tarsiiformes
- 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
122Platyrrhini
- 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.
123Platyrrhini
- 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
124Platyrrhini
- 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
125Cercopithecoidea
- 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.
126Black 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
127Hylobatoidae
- 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
128The 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.
129Pongidae
- 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.
130Orang Utan http//naturescrusaders.files.wordpress
.com/2009/04/orangutan-male.jpg
131Gorillinae
- 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.
132Panini
- 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.
133http//phineasgage.files.wordpress. com/2007/06/07
0617chimp.jpg
http//www.awf.org/files/3972_image2_western_goril
la_MWatson.jpg
134Homini
- Humans largely hairless great ape.
- Posesses advanced reasoning and communication
capabilities and a high degree of technological
sophistication. - Highly social. Widespread.
135Glires 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).
136Pika http//media-2.web.britannica.com/eb-media/16
/3516-004-67E3395A.jpg
137Glires 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.
138Rodents
- 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.
139Beaver 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
140Rodents
- 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.
141Cladistic 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
142Eulipotyphyles
Chiroptera
Laurasiatheria
Perissodacytla
Carnivora
Pholidota
Tylopoda
Suina
Cetartiodactyla
Ruminantia
Hippopotamidae
Cetacea
143Eulipotyphyles (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.
14420.28
145Chiroptera
- 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.
146http//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
147Perissodactyla
- 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.
14820.32
149Carnivora
- 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.
150http//www.cartage.org.lb/en/themes/sciences/zoolo
gy/ Animalclassification/OrderPrimates/carnassials
.jpg
151Pholidota
- 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
152Cetartiodactyla
- 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.
153Traditional 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.
154Eulipotyphyles
Chiroptera
Laurasiatheria
Perissodacytla
Carnivora
Pholidota
Tylopoda
Suina
Cetartiodactyla
Ruminantia
Hippopotamidae
Cetacea
15520.32
156Cetacea
- 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.
157Cetacea
- 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.
158Humpback whale