Monotremes and Marsupials
|Order Monotremata -|| |
echidnas and platypus restricted to Australia, Tasmania, New Guinea
|Montremes||from the Greek monos(single) + trema(hole)- referring to the cloaca . these egg laying mammals are usually put in a single order- Monotremata. . though a recent classification proposes to divide them into the orders Patypoda (platypus along with its fossil relatives and Tachyglossa (echidnas, or spiny anteaters)|
|Primitive Characters Monotremes|| • Primitive characters|
- "therapsid" shoulder
girdle - sprawled posture
- cervical ribs
- epipubic bones (project
forward from pelvis)
- no corpus collosum - no auditory bulla and uncoiled cochlea (only mammals to have this)
|Derived characters Monotremes|| - electroreception|
- highly modified limbs - edentate (no teeth) as adults (platypus young have 3 teeth in
each quadrant) - spurs
|Monotreme Ovaries and Egg||• ovaries larger (relative to body size) than other mammals|
• oviducts open into common . young have "egg tooth" like birds to help break out of egg
• milk secreted by glands in
skin, licked from tufts of fur at concentrations of glands . Platypus are fertilized in the fallopian tubes then they go to the uterus for a while
. Egg is more leathery shell, not calcified
|Monotreme Testes and Sperm|| • testes abdominal, penis in sac in floor of cloaca (not used for urine)|
• sperm are filiforn (thread-like) and reptilian in structure. . male testes are abdominal, they don't drop due to body temp, they don't have to worry about protecting the sperm.
|Monotreme Egg Production #|| • platypus: 1-2 eggs|
• echidna: 1 egg
|Typical Platypus reproduction|
Egg is fertilized in fallopian tubes before entry to uterus . Uterine wall secretes nutritious secretions which are absorbed by fertilized egg,
Egg grows in size (about 3x) .
Egg at fertilization = 4 mm, when laid = 12 mm .
Egg retained in uterus about 28
days while development
proceeds. THEN leathery shell
added, egg laid, 10 more days
of external incubation. (Eggs
sticky, female cradles between
stomach and tail.)
Lactation about 3-4 months.
|Echidna Reproduction|| |
Only 1 egg, incubates in a pouch where hatching occurs.
Young suckle in pouch for about 55 days, when they start to get too
Lactation for about 4 months more.
|Monotremes eAR|| - inner ear bones are fully incorporated into the skull,|
rather than lying in the jaw as in cynodonts and other premammalian
synapsids. The external opening of the ear still lies at the base of the jaw.
|Monotreme Shoulder||- monotremes have extra bones in the shoulder girdle, including an interclavicle and coracoid, which are not found in other mammals.|
monotremes retain a reptile-like gait, with legs that are on the sides of rather than underneath the body. - monotreme hind leg bears a spur in the ankle region;
the spur is non-functional in echidnas, but contains a
powerful venom in the male platypus . All four feet are web, hind leg is more useful for orientation
|Platypus||Order: Monotremata Family: Ornithorhyncidae .|
|Platypus tail||-the platypus is an excellent swimmer and spends much of its time in the water foraging for food . the tail is used for energy (storage of fat reserves) . - uniquely among mammals it propels itself when swimming by an alternate rowing motion of the front two|
feet; although all four feet of the Platypus are webbed
- the hind feet (which are held
against the body) don't assist in
propulsion, but are used for steering
in combination with the tail.
|Platypus eating||-the platypus is a carnivore feeding on annelid worms, insect larvae, freshwater shrimps, and crayfish that . it digs out of the riverbed with its snout or catches while|
- it utilizes cheek-pouches to
carry prey to the surface,
where they are eaten.
- it needs to eat about 20% of its own weight each day and they spend an average of 12 hours each day looking for food. . Keratinized teeth for grounding
|Electrorecption|| • monotremes are only mammals|
known to have a sense of
• platypus locate prey by detecting
electric fields generated by muscular
• closes its eyes, ears and nose each
time it dives and digs in the bottom
of streams with its bill.
|Echidna||Order: Monotremata Family: Tachyglossidae|
|Echidna Living Arrangement|| Echidnas live alone and, apart|
from the burrow created for
rearing young they have no
fixed shelter or nest site. They
do not have a home territory,
but range over a wide area.
|Echidna daily activity||Echidnas are typically active in the daytime; however, they can't deal with heat - they have no sweat glands and do not pant. Therefore, in warm weather they change their pattern|
of activity, becoming nocturnal. They can tolerate cold
temperatures, and hibernate during the winter in very cold
|Echidna Snout|| |
They have snouts which have the functions of both mouth and nose. Their snouts are elongated and slender.
Echidnas have a tiny mouth and a toothless jaw. They using their long, sticky tongue, which protrudes from
their snout, to collect their prey . Texture of Platypus snout is rubbery
|How do Echidnas locate food?|| Echidnas locate food by smell,|
using sensors in the tip of their
snout. They are powerful diggers,
using their clawed front paws to
dig out prey and create burrows
for shelter. . They may rapidly dig
themselves into the ground if they
cannot find cover when in danger.
|Common places to find Echidnas|| They are common in forested areas where there are abundant termite-filled fallen logs . In agricultural areas,|
they are most likely to be found in uncleared scrub; they may be found in grassland, arid areas, and in the outer suburbs of the capital cities.
|Marsupial North America|| Order Didelphimorphia - opossums |
Order Paucituberculata - rat, oppossums
Order Microbiotheria - Monito del Monte
|Marsupials Australia|| Order Dasyuromorphia - numbat, Tasmanian devil, marsupial mice |
Order Peramelemorphia - bandicoots, bilbies
Order Notoryctemorphia - marsupial "mole"
Order Diprotodontia - koala, wombat, kangaroos,possums
|Marsupial Females are Charaterized by?|| Marsupials are often characterized by the female's abdominal pouch, or marsupium. . . This is a poor diagnostic feature as not all marsupials have one and the|
echidna (a monotreme) has a pouch. Only about 50% of species have a permanent pouch.
|Best way to characterize marsupials||They are best categorized by their reproductive mode, specifically the small amount of energy invested before birth. Marsupial litters weigh less than 1% of maternal mass at birth compared to up to 50% in some rodents. (about 5mg)|
|Baby Investment for Marsupials|| Marsupials invest more during lactation and so in the end they are somewhat comparable in total|
investment. . They have exchanged the umbilical cord for the nipple.
|Marsupial Reproduction||• eggs slightly larger than in|
placentals (0.12-0.28 mm
vs 0.07-0.15 mm)
• no invasive placenta
• many have pouch, some
only have folds of skin, and
• uteri separate, but females also have paired vaginae; new, median canal forms at parturition
• young never larger than
about 1 g, no matter size of
a few don't have anything
• in males, penis is bifid (forked) like female vaginae
• scrotum lies in front of
• gestation always short as
or shorter than length of
estrus cycle penis, opposite pattern in most placentals .....capabilities of having multiple pregnancies
|Metabolic Rate Marsupial|| Marsupials have lower metabolic rates than their placental|
counterparts - 70% less.
|Marsupial brain size||They have smaller brains with no corpus collosum.|
|Marsupial Post Natal||They have slower post-natal growth (except for bandicoots).|
|Dentition in Marsupial||Polyprotodont Diporotodont|
longer mandible with small unspecialized lower incisors
a shortened mandible with
the first pair of lower incisors enlarged to meet upper
incisors - usually only one pair
|Hind Foot Digits||Didactylous, Syndactylous|
2nd and 3rd toes fused and in a common skin sheath.
|Didactylous Digit Polyprotodont|| Order Didelphimorphia - New World opossums|
Order Microbiotheria - Monito del Monte
Order Dasyuromorphia - numbat, Tasmanian devil, marsupial mice
|Didactylous Digit Diprotodont||Order Paucituberculata - rat oppossums|
|Syndactylous Digit Polyprotodont|| Order Peramelemorphia - bandicoots, bilbies|
Order Notoryctemorphia - marsupial "mole"
|Syndactylous Digit Diprotodont||Order Diprotodontia - koala, wombat, kangaroos, possums, etc|
|American Opossum|| |
Order: Didelphimorphia Family: Didelphidae
|Didelphimorph size|| Didelphimorphs are small to medium-sized, with the largest about the size of a large house cat, and the smallest the size of a mouse. Only 1 species is north of Mexico|
The marsupium ranges from absent to well developed.
Opossums have more teeth (50) than any other land mammal, except the numbat. The incisors are very small,
the canines large, and the molars are tricuspid. . Most members of this taxon have long snouts, a narrow braincase, and a prominent sagittal crest. . sagital crest- crest on top of skull enhacing muscle attachment for jaw closer control
|Didelphimorphs Stance||Didelphimorphs have a plantigrade stance (flat foot) . the hind feet have an opposable digit with no claw. . Opossums have prehensile tails|
|Opossum Stomach||The stomach is simple, with a small cecum.|
|Didelphimorphs Diet|| Didelphimorphs are opportunistic omnivores with a very|
broad diet. . Their diet mainly consists of carrion, but also eat insects, frogs, snakes, small mammals, earthworms, and
birds , Some of their favorite foods are fruits.
|Didelphimorph Habitat|| - they occur in all habitats from deserts to tropical forests and at elevations up to 3,400 m|
- some are terrestrial burrowers, others are semi-arboreal
- generally solitary
|Water Opossum|| |
Chironectes minimus aka Yapok . .
|the only true aquatic marsupia||The Water Opossum aka Yapok|
|Female Pouch of water opossum||Becomes water tight during dives|
|Shrew Opossum or Caenolestid|| |
Order: Paucituberculata (South America) ----order diverged from the ancestral marsupial line very
early. Family: Caenolestidae . 6 species only in the andes mountains
|Shrew Opossum Habitat|| They live in inaccessible forest|
and grassland regions of the
High Andes. Shrew opossums have not competed well with placental insectivores that fill
the same ecological niches.
|Shrew Opossum Size|| Shrew, or rat, opossums are about the size of a small rat,|
with thin limbs, long, pointed snout and a slender, hairy tail.
|Shrew Opossum Diet||They eat insects, earthworms and small vertebrates;|
|Shrew Opossum Senses|| have small eyes and poor sight, and hunt in the early evening and|
at night, using their hearing and long, sensitive whiskers to
|Shrew Opossum Teeth|| |
They have no marsupium.
They are didactylous and the only non-Australian
|Monito del Monte|| |
Order Microbiotheria (South America) Family: Microbiotheriidae . The Monito del Monte (Spanish
for "little mountain monkey"), is a
small marsupial native only to
Chile and Argentina.
|Monito del Monte Activities|| The species|
is nocturnal and arboreal, and lives
in thickets of Chilean bamboo in
the temperate rain forests of the
southern Andes, aided by its well
furred, partially prehensile tail.
|Monito del Monte Diet||It eats primarily insects, small invertebrates, and fruit.|
|What helps the Monito del Monte Climb||They have very large auditory bullae and pads on their feet to help in climbing|
|Monito del Monte Nests||The Monito del Monte constructs|
spherical nests of water resistant
bamboo leaves. These leaves are
then lined with moss or grass, and
placed in well protected areas of
the tree. .The nests are sometimes
covered with grey moss as a form
of camouflage. These nests
provide them with some protection
from the cold, both when it is
active and when it hibernates. . It stores fat in the base of it's tail for
winter hibernation being able to
double their body weight within a
|Monito del Monte is Related to?||More closely related to Australian forms than Ameridelphia.|
Order: Dasyuromorphia (Australia) Family: Myrmecobiidae
|Tasmanian Devil, Marsupial Mice|| |
Order: Dasyuromorphia (Australia) Family: Dasyuridae
|Tasmanian Wolf|| |
Order: Dasyuromorphia Family: Thylacinidae Thylacinus cynocephalus ----- recently extinct
|Family Dayuridae Size|| Range in size from the smallest marsupial (Pilbara ningaui) ( 5g) to the largest marsupial carnivore (the|
Tasmanian devil) (8 kg).
|Family Dayuridae Habitat|| Throughout Australasia|
inhabiting all terrestrial and semiarboreal habitats from
deserts to high-elevation rain forests.
|Family Dayuridae Marsupium|| Marsupium absent or poorly developed. In several|
species the males have a mass die-off after breeding.
|Tasmanian Devil(Sarcophilus harrisii)|
the largest surviving carnivorous
marsupial in Australia (8 kg) .
It has a squat and thick build,
with a large head and a tail
which is about half its body
length . Unusual for a marsupial, its forelegs are slightly longer than its hind
legs . Devils can run up to 8 Tasmanian devil mph for short distances .
The fur is usually black, although irregular white patches on the chest and rump are common.
|Tasmanian Devil Tail|| They store body fat in the tail.|
An ano-genital scent gland at
the base of its tail is used to
mark territory and they
produce an odor that rivals
|Tasmanian Devil Senses|| They have long whiskers on|
the face and on top of the head
to locate prey when foraging
in the dark, and aid in
detecting other devils . Hearing Tasmanian devil
is the dominant sense, but it
also has an excellent sense of
|Tasmanian devil teeth|| They have the strongest bite of any living mammal|
and has one set of teeth that grows slowly throughout its life.
|Tasmanian Devil Eating||They can take prey up to the|
size of a small kangaroo, but are
generally opportunistic, and eat
carrion more often than they
hunt live prey They will eat anything up to the size of sheep.
They eat 15% of body weight
each day; however, they can eat
up to 40% of their body weight
in 30 minutes if the opportunity
arises. They eliminate all traces of a carcass, devouring the
bones and fur in addition to the
meat and internal organs
|What is threatening Tasmanian Devil|| Now threatened by a facial|
|Tiger Quoll|| |
Dayurus maculatas The tiger quoll, also known as the spotted-tail quoll, the spotted quoll, the spotted-tailed dasyure or
(erroneously) the tiger cat, is a mainland Australia's largest carnivorous marsupial and is considered an apex
|Fat tailed Antechinus|| |
The fat-tailed antechinus is 10 cm long with a 8 cm tail;
it weighs 20-45g . It has a carrot-shaped tail swollen with fat (incrassate) which serves as a food reserve . Its fur is grey-brown. It has litters of up to six young, born in July-September. It is an insectivorous, nocturnal species.
|Antechinus Shrew||Almost all Antechinus species are semelparous. . . . Breeding occurs in winter (usually August-September) at a time|
when there is little food available in the environment, and
In order to ensure breeding success, male antechinus shrews strip their body of vital proteins and also suppress the immune system so as to free up additional metabolic
energy. . following the breeding season there is a complete die-off
of physiologically exhausted males. Breeding is intensely competitive.
|Antechinus Shrew Male|| Males produce large amounts of testosterone and mate-guarding occurs in the form of protracted|
copulation (up to twelve hours in some species).
|Antechinus Shrew Females|| Females can store sperm, get pregnant and give birth after|
all males in population are dead. (males live 1 yr, females
usually 2, very rarely 3)
|Numbat or Banded Anteater|| |
Family: Myrmecobiidae . Unlike most other marsupials, the
numbat is diurnal.
|Numbat Eating|| They are insectivores and exclusively eat termites (up to 20 000 /day) It|
20,000 day). digs termites from loose earth with its front claws and captures them with its long sticky tongue.
Has 52 teeth
|Numbat Living||At night, they retreat to a nest, typically a burrow 1-2 m long|
terminating in a spherical chamber lined with soft plant material:
grass, leaves, flowers and shredded bark. The numbat is able to
block the opening of its nest, with the thick hide of its rump, to block
access by a potential predator.
|Numbat Marsupium||No marsupium, young hang from belly hair.|
Order Peramelemorphia (Australia, Indonesia)
Family: Thylacomyidae -bilbies (1, 2)
|Bandicoot and Echymiperas|| |
Order Peramelemorphia (Australia, Indonesia) Family: Peramelidae - bandicoots and echymiperas
|Bandicoot and Echymipera Marsupium|| Chorioallantoic placenta.|
Well developed marsupium,
|Bandicoot Appearance|| have short limbs and|
tails, smallish, mouse-like ears,
and a long, pointed snout.
|Bandicoot Eating|| They are nocturnal omnivorous with|
nocturnal, omnivorous, . soil-dwelling invertebrates forming
the major part of their diet; they
also eat seeds, fruit, and fungi.
Their teeth are unspecialized.
|Peramelids (Bandicoot) Females|| Female peramelids have a pouch that opens to the rear, and contains|
eight teats . The female has 8 teats and this allows the female to produce
more than one litter ata a time, and gives peramelids an unusually
high reproductive rate compared with other marsupials
|Peramelids (Bandicoot) Gestation||The gestation period of peramelids is the shortest among mammals, at just 12.5 days, the young (usually 4) are weaned at around two months of age, and reach sexual maturity at just three months.|
|Comparing Bilbies to Bandicoots||Bilbies have longer tails, bigger ears, and softer fur . bilbies are excellent burrowers and build extensive|
tunnel systems with their strong forelimbs and well-developed claws. A bilby typically makes a number of burrows within its home range, up to
about a dozen; and moves between them, using them for shelter both
from predators and the heat of the day.
|Bilbies and Bandicoot commonalities||Muzzle and very long ears. The size of their ears allows them to have better hearing|
|Bilbies Eating||They are nocturnal omnivores that do not need to drink water, as they get all the moisture they need from their food,|
which includes insects and their larvae, seeds, spiders, bulbs, fruit,
fungi, and very small animals. . Most food is found by digging or
scratching in the soil, and using their very long tongues.
|Female Bilbie|| The female bilby's pouch faces|
backwards, which prevents her pouch from getting filled with dirt while she is digging
|Marsupial Mole|| |
Order Notoryctemorphia (Australia)
Family: Notoryctidae Marsupial moles provide a remarkable example of convergent
|Marssupial Mole Living|| Marsupial moles are completely|
fossorial, coming to the surface
only occasionally, probably
mostly after rains.
Syndactylous with huge digging
claws, no external eyes or ears.
They do not dig permanent
burrows, they "swim" through the
sand, filling the tunnel in behind
them as they move.
|Marssupial Mole Feeding||They are insectivorous, feeding primarily on beetle larve and caterpillars.|
|Marssupial Mole Teeth||Their teeth have a somewhat simplified structure, but their dental formula is similar to that of other marsupials|
|Digits in arboreal species||Very diverse group but all species are diprotodont and syndactylous . In many arboreal species, including the koala, the ringtail possums, and cuscuses, the first two digits|
of the forefeet oppose the last three and so they are schizodactylous. On the hind foot the big toe is opposable.
They lack lower canines.
the first two digits
of the forefeet oppose the last three
|Koala Facts||• occupies Eucalyptus woodlands.|
closely related to wombats - have
vestigial tail even though arboreal .
• cheek teeth are closed-rooted - very
unusual for an herbivore.
• extremely long cecum
• along with bandicoots and bilbies, have Koala
chorioallantoic placentae without villi
• sexually dimorphic - males twice as big as females . • specialized herbivore
• 8-12 kilograms
• sedentary, slow growing
• save energy by staying in
• 5-7 months pouch life
• posterior opening
|Wombat Teeth|| |
• similar to rodents in dental morphology, and often
considered convergent with marmots (actually more like a terrestrial beaver).
• single pair of upper and lower incisors and a diastema • rodent-like herbivores with large masseters
continuously growing teeth (unique in marsupials)
|Wombat Marsupium||rear-facing marsupium|
|Potoroos and Bettongs|| Order Diprotodontia|
similar to small wallabies with elongated hind feet and they move by hopping. they have carnassial premolars with a sacculated stomach
|Potoroids Eating|| they eat a wide variety of vegetable foods, most have a|
particular taste for the fruiting bodies of fungi, and often
depend on fungi to see them through periods when there
is little else to eat in the dry Australian bush
|Potoroids Habitat|| in the dry Australian bush.|
This limits its habitat range as
it needs to live in a moist
environment, with dense
• largest family with the kangaroos, wallaroos, quokkas,
• browsers and grazers, some are arboreal. Upper and
lower incisors do not occlude
• they chew their cud.
• molars are hypsodont and, like elephants and manatees, the molars
drift forward (mesial drift) and fall out the front as they wear out
|Tree and Terrestrial Kangaroo Stomach|| In both tree kangaroos and terrestrial|
kangaroos, the stomach is large,
containing bacteria capable of breaking down tough fibrous food.
|Terrestrial Kangaroo eat|| Terrestrial kangaroos eat grass primarily, while|
leaves and fruit are the main foods of
tree kangaroos. Foregut Fermenter
|Tree Kangaroo eat|| Tree kangaroos have a broader diet that|
may include bark, sap, and flowers.
When they can get them, they eat eggs,
birds, and other small animals, too
|Terrestrial Kangaroo and Water|| |
Most terrestrial kangaroos drink very little water. They can get most of the water they need by eating green plants. . Red kangaroos can go without water for two or three months (red kangaroo habitat is generally quite
xeric). . The tammar wallaby (Macropus eugenii) is able to drink saltwater.
|Musky Rat Kangaroo|| |
Family: Hypsiprymnodontidae . It is the smallest macropod that is
quadrupedal and is diurnal. It has a hairless tail, . eats fallen fruit,
fungi, and large seeds, as well as small invertebrates.
|Musky Rat Kangaroo Movement|| It moves by extending its|
forelegs and then bringing
both of its hind legs
forward, and uses an
opposable digit on the
hindfoot to climb trees.
|Musky Rat Kangaroo Habitat|| This is a rat-sized marsupial species found in the rainforests of New|
Guinea and northeast Australia
|Cuscus Facts|| • phalangers, cuscus, brush-tailed possum, scaly-tailed possum. |
• arboreal with a prehensile tail and wooly fur, anterior opening marsupium.
• large hands and feet with digits 1 and 2 opposable to 3, 4 and 5 on hand
• low BMR omnivores
|Cuscus eats|| The cuscus eats mostly fruit, but|
will also eat leaves and sometimes
insects and small vertebrates .
|Feathertail Glider|| |
|Feathertail Glider facts||The world's smallest gliding mammal -|
named for its long feather-shaped tail. They are the size of a small mouse but
can glide up to 25 m
The tail is thin, moderately prehensile, and almost hairless except for two rows of long, stiff hairs on either side. The tail
is used to grip small branches, and to
control gliding flight: steering and thenbraking. Patagium between elbows andknees.
|Feathertail Glider eats|| They eat nectar, pollen and arthropods|
(have bunodont dentition).
|Only marsupials known to hibernate live in||Australia|
|Pygmy Possum|| |
|Pygmy Possum Facts||Pygmy possums range in length from|
about 5 to 12 cm, and weigh between 10 to 50 g. . . They are nocturnal and
omnivorous, living on a diet of
invertebrates, fruit, seed, nectar and
pollen. . . They are excellent climbers, due
in part to their possession of a prehensile tail. Although they cannot glide like
some other species of possum, some
species are able to leap a long distance.
All use torpor, but one species is the only known marsupial hibernator (store fat in
|Ringtailed Possums|| Order Diprotodontia|
Ring tailed possum . Physically they appear very similar to the pygmy possum except fort their greater size. . Even so, they are relatively small
animals, with the largest being cat-sized, and they weigh between 200 grams and 2 kilograms. . They have grasping hands and
feet with opposable first toes on their
hindfeet, and, in all species except the
Greater glider, they have a prehensile tail.
They are nocturnal, with large eyes. Have a gliding membrane from elbow to ankle.
|Coprophagus Marsupial|| Ring tailed possum All species feed almost entirely on leaves. very large cecum to|
enable them to digest this tough and fibrous food. . . They have selenodont teeth and they lack lower canines.
|Striped/ Gliding Possum|
• one sub group eats sap and nectar
but another group eats insects
• relatively small (100-700g), with a
prehensile tail and a patagium going
from wrist to ankle
• scent important for group cohesion.
• sharp claws
• in insect feeders - one digit is
• anterior facing marsupium divided
into two compartments
Family: Tarsipedidae .
One of the very few entirely nectarivorous mammals; . it has a long, pointed snout and
a long, protrusible tongue with a brush tip that gathers pollen and nectar, like a honeyeater or a hummingbird.
Mainly nocturnal but will come out to
feed during daylight in cooler weather.
Generally, though, it spends the days
asleep in a shelter of convenience: a rock cranny, a tree cavity, the hollow inside of a grass tree, or an abandoned bird nest.
When food is scarce or in cold weather, it becomes torpid to conserve energy. . Smallest mammalian newborn - 5 mg
|Honey Possum Teeth|| The honey possum has 22 small|
degenerate teeth, except for the
procumbent lower incisors.
|Honey Possum Tongue|| |
Long, protrusible tongue with a
brush tip that gathers pollen and