Mammals are classified into 5420 species within 152 families and 29 orders. The two subclasses are Prototheria and Theria. Prototheria contains monotremes like platypuses and echidnas that lay eggs. Theria contains marsupials in the infraclass Metatheria that give birth to immature young developing further in pouches, and placentals in Eutheria that give live birth to mature young. Marsupials include opossums and kangaroos, while placentals make up the majority of mammal species and include humans, whales, bats and more. Classification systems continue to evolve as new genetic and fossil evidence is discovered.

1. CLASSIFICATION OF
MAMMALS
Speaker:
Dr. Showkat Ahmad
MBBS,PGDMCH
DEPTT OF ANATOMY
GOVT MEDICAL COLLEGE
SRINAGAR

2.  “And surely we have honoured the children of
Adam, and carried them on the land and at
the sea, and provided them with good things,
and we have made them to excel by an
appropriate excellence over many of those we
created.” (17:70)
 “And they ask you about the spirit. Say: The
spirit is from the command of my Lord, and
you are not given ought of knowledge but a
little.” (17:85)

3.  Mammalia is a class of animals within the Phylum Chordata
 Mammals are defined as vertebrates that give birth to live
young ones (viviparity) ,possess hairs which insulate their
bodies and mammary glands for feeding young ones with
milk and share a unique jaw articulation.
 They also possess a four-chambered heart, a large
cerebral cortex, three distinctive bones: [incus, malleus and
stapes] in the middle ear, a diaphragm for breathing,
heterodont and thecodont dentition, limbs attached under
the body, dicondylic skull and acoelous vertebrae.
 Mammals also include humans who are the most highly
advanced organisms on Earth. ‘Mammal’ possess
complex range of form and function in them; and also the
large extent of individual flexibility which they demonstrate
through their behavior.

4.  Many earlier ideas have been completely abandoned by
Linnaeus and modern taxonomists, among these are the
idea that bats are related to birds or that humans
represent a group outside of other living things.
 Mammalian classification has been through several
iterations since Carl Linnaeus initially defined the class.
 Most significantly in recent years, cladistic thinking has
led to an effort to ensure that all taxonomic designations
represent monophyletic groups. The field has also seen a
recent surge in interest and modification due to the
results of molecular phylogenetics.

5.  Mammals are actually a class organized into 5420
species; which are further sub-classified into 135
families, 1,000 genera, 29 orders, and 2 subclasses.
 While studying these subclasses, we come to know
several mammals that were parted some 200-million
years ago. These primitive mammals include egg-laying
Prototheria (platypus and echidnas being the only
survivors) along with live-bearing theria.
 George Gaylord Simpson's[1945] "Principles of
Classification’’ laid out a systematics of mammalian
origins and relationships that was universally taught
until the end of the 20th century.

6.  Though field work gradually made Simpson's
classification outdated, it remained the closest
thing to an official classification of mammals.
Various trials have been made to classify
mammals
 Molecular classification
 Standardized classification
 McKenna/Bell classification
 Luo, Kielan-Jaworowska, and Cifelli
classification
 Simplified classification
 No classification system is universally accepted;
McKenna & Bell (1997) and Wilson & Reader

7.  Based on
 Relatedness
 Overall similarity
 Use morphology (and genetics)
 Shared traits are evidence
 of shared ancestry
shared traits:
• Internal fertilization;
most bear live young ones
• Mammary glands
• Fur/hair
• 1 jaw bone
• 3 bones in ear
• Endothermy(warmblooded)
Non-mammals don’t have these traits• Why?
 Branched off before these traits evolved
 Help distinguish mammals & non-mammals

8. Afrotheria
Xenarthra
Boreoeutheria
Euarchontoglires
Laurasiatheria
Molecular results are still
controversial mainly
because they are not
reflected by
morphological data and
thus are not accepted by
many systematists.
Fossil taxa in most
cases are not included.

9.  Subclasses
1. Protheria
2.Theria
2.1Metatheria[marsupial]
2.2Eutheria [placental]
 This approach
emphasizes an initial
split between egg-laying
prototherians and live-
bearing therians.
 No attempt is made in
this classification to
further distinguish among
the orders within these
subclasses and infra
classes.
 This system also makes
no note of the position of
entirely fossil groups.

10. McKenna inherited the project from Simpson and,
with Bell, constructed a completely updated
hierarchical system, covering living and extinct taxa ,
that reflects the historical genealogy of Mammalia.
and introduced some fine distinctions such as
legions and sublegions (ranks which fall between
classes and orders).
 Subclass Prototheria
 Subclass Theriiformes
 Several important fossil mammal
discoveries have been made that have
led researchers to question many of the
relationships proposed by McKenna and
Bell (1997).

11. Luo et al. (2002) summarized existing ideas and
proposed new ideas of relationships among
mammals at the most basal level.
They argued that the term mammal should be
defined based on characters (especially the
dentary-squamosal jaw articulation) instead of a
crown-based definition (the group that contains
most recent common ancestor of monotremes and
therians and all of its descendants).
They also define their taxonomic levels as clades
and do not apply Linnean hierarchies.

12.  Unnamed clade 1 - a clade
that contains all other
mammals. These are
characterized
by determinant growth and
occlusal features of the
cheek teeth.
 Unnamed clade 2 - a clade
containing all living
mammals and some fossil
relatives. It is characterized
by the loss of a
postdentary trough and a
widened braincase.
Crown-group Mammalia - the
group that contains most recent
common ancestor
of monotremes and therians and all
of its descendants. This group is
defined by additional characters
relating the occlusion of molars and
the presence of a well-
developed masseteric fossa
Trechnotheria -
Therians, spalacotheriids and their
relatives. They are characterized by
features of the scapula, tibia,
and humerus.
Cladotheria
Zatheria
Boreosphenida
†Eutriconodonta

13. WILSON AND REEDER recognised about 5420 species
of living mammals which are further sub-classified into
152 families, 1229 genera, 29 orders, and 2 subclasses.
MOST SPECIES OF EXTANT MAMMALS have already
been placed in the classification but approximately 10-
12new species continue to be named each year.
Still ,the numbers of genera and species are
insignificant in comparison with those for
invertebrates. The mammalian classsification
presented here is largely that of various authors in
WILSON AND READER [2005] and is based on
phylogenetic relationships as currently understood.

14. classification class mammalia
5420 species/152
families/29
orders/
SUBCLASS
Protheria
no infra class
monotremata
(platypus and
echidna)
Family
Ornithorhynchidae,
duck-billed platypus
(Ornithorhynchus
anatinus)
Family
Tachyglossidae,
[spiny anteaters]
SUBCLASS
theria
INFRA CLASS
METATHERIA
[marsupials]
7 orders
15
families
334
species
INFRA CLASS
EUTHERIA
[placentals]
132
Families
21 orders
5081
species

16.  Mammals that lay eggs with leathery shells and
nourish the young ones with milk from
primitive(open) mammary glands.
 They possess a cloaca like reptiles, have no urinary
bladder but possess hairs, No teeth, but single jaw
bone
 5 species in 2 families in Order Monotremata
Earliest monotreme: 125 mya
Teinolophos

17. Family Ornithorhynchidae: platypuses
Family Tachyglossidae: Echidnas (spiny anteaters)
platypuses spiny anteaters

18. Echidnas are insectivores.
•They use their long, sticky tongue to catch
ants, termites, other insects, and earthworms
When attacked, the echidna will quickly
burrow into the ground or curl up into a ball

19. 4470 species in 25 orders
• Give birth to live young ones
• Specialized dentition based on diet
• All continents

20.  Body covered with fur; female
with marsupium;give birth to
extremely immature
infants,complete their
development in
marsupium;poorly developed
or absent corpus callosum
diaphragm and seven
cervical vertebrae are present
and the marsupial bone
(epipubis) present).
 334 species in 7 orders
 Earliest marsupial: 125 mya
Sinodelphys

21. Order Didelphimorphia[89/1]
Common opossums
Virginia opossum

22. Order Didelphimorphia[89/1]
Order Paucituberculata[6/1] shrew opossums
long-nosed shrew
opossum

23.  Order Didelphimorphia
 Order Paucituberculata
 Order Microbiotheria[1/1]
monito del montes
South American
monito del montes

24.  Order Didelphimorphia
 Order Paucituberculata
 Order Microbiotheria
 Order Dasyuromorphia[71/3]
most carnivorous
marsupials
Tasmanian devilTasmanian tiger

25.  Order Didelphimorphia
 Order Paucituberculata
 Order Microbiotheria
 Order Dasyuromorphia
 Order Peramelemorphia[22/3]
eastern barred
bandicoot
bandicoots

26.  Order Didelphimorphia[89/1]
 Order Microbiotheria[6 sp/1]
 Order Paucituberculata[1/1]
 Order Dasyuromorphia[71/3]
 Order Peramelemorphia[22/3]
 Order Notoryctemorphia[2/1]
marsupial moles
southern marsupial mole

27.  Order Didelphimorphia[89]
 Order Microbiotheria[6 sp/1]
 Order Paucituberculata[1/1]
 Order Dasyuromorphia[71/3]
 Order Peramelemorphia[22/3]
 Order Notoryctemorphia[2/1]
 Order Diprotodontia[144/11]
[Kangaroos, wallabies, koalas] Kangaroos

28. Order Diprotodontia[11 families]
( Kangaroos, wallabies, koalas
Possums ,vombats)
• Family Macropodidae
• Family Phascolarctidae
• Family Vombatidae
• Family Borramyidae
• Family Phalangeridae
• Family Pseudocheridae
• Family Petauridae
• Family Tarsipedidae
• Family Acrobatidae
• Family Hypsipyrmnitidae
• Family Potoroidae

29. True mammals which are completely
viviparous, with chorio-allantoic
placenta and in which complete
development takes place in uterus,so
mature infants are born,well
developed corpus
callosum,marsupium absent
• 4136 species in 21 orders
• Longer internal gestation
• Placenta nourishes embryo
• Single uterus & vagina
• More developed infants
• All continents
Earliest Eutherian: Eomaia
Eomaia

30. • Order Cetacea[11/84]
beached humpback whale (Big Sur)
killer whale
[whales, dolphins,porpoises]
California grey whale

31. Order Cetacea[11/84]
Order Sirenia[5/2]
West African manatee
West Indian manatee
(dugongs, sea cows,manatees)
dugong

32. • Order Cetacea [11/84]
• Order Sirenia [5/2]
• Order Tubulidentata [1/1]
aardvarks

33. • Order Cetacea
• Order Sirenia
• Order Tubulidentata
• Order Pholidota[8/1]
ground pangolin
pangolins
Indian pangolin

34. • Order Cetacea[84/11]
• Order Sirenia[5/2]
• Order Tubulidentata[1/1]
• Order Pholidota[8/1]
• Order Hyracoidea[4/1]
western tree hyrax
[hyrax]
rock hyrax

35.  • Order Cetacea[84/11]
 • Order Sirenia[5/2]
 • Order Tubulidentata[1/1]
 • Order Pholidota[8/1]
 • Order Hyracoidea[4/1]
 • Order Proboscidea[3/1]
[Elephants]
Asian elephant
African elephant

36.  • Order Cetacea[84/11]
 • Order Sirenia[5/2]
 • Order Tubulidentata[1/1]
 • Order Pholidota[8/1]
 • Order Hyracoidea[4/1]
 • Order Proboscidea[3/1]
 • Order Pilosa[10/4]
[anteaters & tree sloths]
Giant anteater,long tubular
snout,bushy tail( C. & S. America)

37.  • Order Cetacea[84/11]
 • Order Sirenia[5/2]
 • Order Tubulidentata[1/1]
 • Order Pholidota[8/1]
 • Order Hyracoidea[4/1]
 • Order Proboscidea[3/1]
 • Order Pilosa[10/4]
 • Order Afrosoricida[51/2]
[Tenercs ]
 • Order Soricomorpha[428/4]
[shrews and moles]
southern short-tailed shrew
European mole

38.  • Order Cetacea[84/11]
 • Order Sirenia[5/2]
 • Order Tubulidentata[1/1]
 • Order Pholidota[8/1]
 • Order Hyracoidea[4/1]
 • Order Proboscidea[3/1]
 • Order Pilosa[10/4]
 • Order Afrosoricida[51/2]
 • Order Soricomorpha[428/4]
 • Order Artiodactyle[240/10]
(even-toed ungulates)
[Examples;Pigs,hippos,
Giraffee,sheep,goats]
(Nile Hippopotamus)
(Central & eastern Africa)
giraffe

39. Family Hippopotomidae
(hippopotomuses)
• 2 species
Family Giraffidae (giraffe,
okapi)
• 2 species, both African

40.  1 Order Cetacea[84/11]
 2 Order Sirenia[5/2]
 3 Order Tubulidentata[1/1]
 4 Order Pholidota[8/1]
 5 Order Hyracoidea[4/1]
 6 Order Proboscidea[3/1]
 7 Order Pilosa[10/4]
 8 Order Afrosoricida[51/2]
 9 Order Soricomorpha[428/4]
 10 Order Artiodactyle[240/10]
 11 Order
Perissodactyla[17/3]
[ odd-toed ungulates]
(Horses,Rhinos and Zebras)
Grant’s zebra
Domestic horse
Asian or Indian rhino
(Nepal, N.E. India)

41. • 19 species in 3 families
• Asia, Africa, Americas
Herbivores
Family Equidae
(horses, asses, zebras)
• 10 species
Excellent peripheral vision
Family Tapiridae
(tapirs)
• 4 primitive species
Family Rhinocerotidae
(rhinoceroses)
• Critically endangered

42.  12 Order Scandentia  treeshrews
pen-tailed treeshrew large treeshrew

43. •12 Order Scandentia
•13 Order Dermoptera
Phillipine colugo
colugos
Sunda colugo

44. • Order Scandentia
• Order Dermoptera
• 14 Order Chiroptera
leaf-nosed bat Coromo black flying
bats

45. • Order Scandentia
• Order Soricomorpha
• Order Dermoptera
• Order Chiroptera
• 15 Order Macroscelidea
elephant shrews
black and rufous elephant shrewcheckered elephant
shrew

46.  • Order Scandentia
 • Order Dermoptera
 • Order Chiroptera
 • Order
Macroscelidea
 16• Order Cingulata
(armadillos)
Nine-banded armadillo
( Mexico, C. &S. America,
Caribbean)
Three-banded armadillo
South America

47.  • Order Scandentia
 • Order Dermoptera
 • Order Chiroptera
 • Order Macroscelidea
 • Order Cingulata
 17 Order Lagomropha[92/3]
(rabbits, hare, pikas)
Domestic rabbit

48.  • Order Scandentia
 • Order Dermoptera
 • Order Chiroptera
 • Order Macroscelidea
 • Order Cingulata
 • Order Lagomropha[92/3]
 18 Order Rodentia [2278/34]
Domestic rat (aka Norway rat)
Domestic mouse (aka feeder
mice, fancy mice)
Grey squirrel

49. • 2278 species/34 families;
40% of mammals
• Large, continuously growing incisors
• High reproductive rates
• Many colonially living
• 3 groups based on jaw muscles
• Cavy-like
• Squirrel-like
• Mouse-like

50. 1.Suborder Hystricomorpha (cavy-like)
• Capybara,porcupine, chinchilla,
naked mole rat,guinea pig
(Africa, Asia, Americas)
Capybara Domestic guinea pigChincilla
N.A. porcupine

51. prairie dogs
Grey squirrel
Domestic rat
2• Suborder Sciuromorpha(squirrel-like)
Squirrel, beaver, woodchuck,
chipmunk, prairie dogs, gophers
Global distribution.
3.Suborder Mymorpha (mouse-like)
¼ of all mammal species
Mice, rats, voles, lemmings, hamsters,
gerbils, muskrat.
Woodrat (aka pack rat)

52.  • Order Scandentia
 • Order Dermoptera
 • Order Chiroptera
 • Order Macroscelidea
 • Order Cingulata
 • Order Lagomropha[92/3]
 • Order Rodentia [2278/34]
 19 Order Erinaceomorpha[24/1]
[hedgehogs]
European hedgehog
long-eared hedgehog

53.  • Order Scandentia
 • Order Dermoptera
 • Order Chiroptera
 • Order Macroscelidea
 • Order Cingulata
 • Order Lagomropha[92/3]
 • Order Rodentia [2278/34]
 • Order
Erinaceomorpha[24/1]
 20 Order Carnivora[286/15]
 Most meat-eaters, some
omnivores,
 Binocular vision, good
sense of smell & hearing

54. Family Procyonidae (raccoons & allies]
Family Felidae [cats, 38 species]
• Obligatory carnivores
e.g Siberian tiger,Sumatran tiger,
African lion,Snow leopard,Fishing cat
Family Viverridae (civets, genets,mongooses)
Family Canidae [wolves ,foxes and jackals]
KinkajouCoati (aka coatimundi)

55.  Family Mephitidae
 Family Nandiniidae
 Family Hyaenida
 Family Phocidae
 Family Eupleridae
 Family Ursidae
 [Largest carnivores,
 Polar bear,Spectacled bear,]
 Family Ailuridae (true seals)
 Family Mustelidae (weasels, badgers,
& allies)
 Family Odobenidae[ walruses ]
 Family Otariidae [Seals, sea lions]
 Family Herpestidae [mongooses]

56.  • Order Scandentia[20/2]
 • Order Dermoptera[2/1]
 • Order Chiroptera [1116/19]
 • Order Macroscelidea [15/1]
 • Order Cingulata [21/1]
 • Order Lagomropha[92/3]
 • Order Rodentia [2278/34]
 • Order Erinaceomorpha[24/1]
 • Order Carnivora[286/15]
 21 Order Primates[376/15]
Primates have
 well developed
hands and feet, with
fingers and toes,
opposable thumb.
 have eyes forwards
in the head giving
them stereoscopic
vision
 Large brains, flatter
faces ,Shorter
snoutBased on fossil evidence, the earliest
known true primates, represented by the
genus Teilhardina, date to 55.8 million
years old

57. Family Hominoidea
• Apes & humans
• Able to swing below branches,No
tail,Larger brain than monkeys, Shorter
snout
Family Hylobatidae [Gibbons]
Family Cheirogaleidae[dwarf Lemurs]
Family Cercopethicidae[Old world
monkeys, Baboons, macaques, guenon]
Family Galagidae[Galagos]
Family Aotidae [Night monkeys]
Family Indriidae[Wooly lemurs]
Family Pethicidae [titis and sakis]
Family Atelidae [Howlers]

58. Primates typically have grasping
hands and feet in addition to
relatively large brains. They have
flatter faces than most other
mammals.
350 species/15 families
Family Lemuroidea (lemurs]
Family Daubentonoidea[aye aye]
Family Lepilemuridae [sportive
lemurs]
Family Tarsiidae [tarsiers]
Family Cebidea[Squirrel monkeys
Black howler monkey, New World monkeys]
Family Hominidea
[ Apes & humans]
( Able to swing below branches,No tail,
Larger brain than monkeys,)
Squirrel monkeys
Black howler monkey
lemurs

59.  Charles Darwin believed we are similar to animals, and merely
incrementally more intelligent as a result of our higher
evolution.
 But according to Marc Hauser, director of the cognitive
evolution lab at Harvard University, in contrast to Darwin's
theory of a continuity of mind between humans and other
species, a profound gap separates our intellect from the animal
kind.
 Hauser and his colleagues have identified four
abilities of the human mind that they believe to be
the essence of our "humaniqueness" mental traits
and abilities that distinguish us from our fellow
Earthlings. They are: generative computation,
promiscuous combination of ideas, the use of mental

60.  1. Generative computation
Humans can generate a practically limitless variety of words
and concepts. We do so through two modes of operation
recursive(allows us to apply a learned rule to create new
expressions) and combinatorial( mix different learned
elements to create a new concept).
 2. Promiscuous combination of ideas
"Promiscuous combination of ideas, "allows the mingling of
different domains of knowledge such as art, sex, space,
causality and friendship thereby generating new laws, social
relationships and technologies.“
 3. Mental symbols
Mental symbols are our way of encoding sensory
experiences. They form the basis of our complex systems of
language and communication. We may choose to keep our
mental symbols to ourselves, or represent them to others
using words or pictures.
 4. Abstract thought
contemplation of things beyond what we can sense.

61.  The Kitti’s hog-nosed bat is the smallest mammal weighing
no more than 1.5 g (0.05 oz), while the largest mammal in
the world is blue whale;
 the wolves are known to travel 1,000 sq. km (400 sq. mi);
the Naked mole rat do not leave one burrow;
 the female Virginia opossums litters up to 27 babies;
orangutan gives birth to one live baby.
 None of the aspects of these diverse lives of mammals is
random. On the other hand, each individual mammal tries
to expand its skill and fitness as compared to their other
counterparts, .