monos "single"+ trema "hole“, reffering to the cloaca

Monotremata

o Kingdom: Animaliao Phylum: Chordata

o Class: Mammaliao Subclass: Prototheriao Order: Monotrematao Families:oKollikodontidae†oSteropodontidae†oOrnithorhynchidae - PlatypusoTachyglossidae

oTachyglossus – Short-beaked echidnaoZaglossus – Long-beaked echidna

Scientific classification

Egg-laying mammals , they lay heavily yolked eggs.

The egg is retained for some time within the mother, who actively provides the egg with nutrients.

EndothermicLacks pinna (has only ear slits)3 bones in middle earBrain lacks corpus callusom

They have no nipples, a milky fluid oozes out from modifies sweat glands onto tufts of hairs in shallow pits of the abdomen, from which the young lick it up.

The monotreme leg bears a spur in the ankle region, the spur is non-functional in echidnas, but contains a powerful venom in the male Platypus.

Ornithorhynchidae Spends most of their time in

the water. They have webbed feet for

swimming and for walking on muddy river bottoms.

Soft, rubbery, sensitive, beaklike muzzle with which they detect invertebrates.

1 – 3 eggs

Tachyglossidae Terrestrial animals They have long, sticky

tongues and stout claws to gather food.

Armed with shard quills and rolls into a ball for protection.

Usually produces 1 egg only

Ornithorhynchus anatinus

Ornithorhynchidae

Tachyglossus - T. a. setosus

Zaglossus - Zaglossus bruijni

Tachyglossidae

Marsupiala

o Kingdom: Animaliao Phylum: Chordata

o Class: Mammaliao Subclass: Theriao Infraclass: Marsupialiao Order:

Didelphimorphia Paucituberculata Microbiotheria Dasyuromorphia Peramelemorphia Notoryctemorphia Diprotodontia

Scientific classification

Non-placental mammals Yolk sac serves as placenta give birth to premature young climbs from the mother's

birth canal to the nipples. it grabs on  with its mouth and continues to develop

Some marsupials have a rudimentary placenta that functions for only a short time, such as the bandicoot

females typically have an external pouch – “marsupium”  in which the immature young are raised after birth until early infancy

Short gestation times  is due to having a yolk-type placenta in the mother marsupial (8-43 days)

Epipubic bones (both sexes; whether or not they have pouches)

The female has two reproductive organ. Both open externally through one orifice, but lead to different compartments within the uterus. Males usually have a two-pronged reproductive organ, which corresponds to the females' two reproductive organ.

Teeth are either diprotodont ("two front teeth") or polyprotodont ("many front teeth")

 Digits are either didactylus (separate; ancestral state) or syndactylus ("fused toes")

Order Didelphimorphia

Opossum

Rat Opossums

Order Paucituberculata

Order Microbiotheria

Monito del Monte

Order Dasyuromorphia

NumbatThylacine

Dasyure

Order Peramelemorphia

Bandicoots

Order Notoryctemorphia

Marsupial Moles

Order Diprotodontia

Wombat

Kangaroo

What are the similarities and differences of Monotremes and

Marsupials?

SimilaritiesSeveral mammalian characteristics

VertebratesEndothermicPresence of fur/skin/hairBreathing through lungsProduction of milk to feed young3 middle ear bones

Both lack corpus callosumIt is a brain structure that connects the left and

the right hemisphere of the brain

Presence of epipubic bonesA rod-like bone which projects forward from

the pelvis. In female marsupials, supports the Marsupium.

Epipubic bone of platypus

Epipubic bones of Virginia opposum

Differences1) Monotremes are egg-laying, while

marsupials give birth to live, helpless young.

2) Monotremes excrete milk through mammary glands located in the skin, while marsupials have nipples where milk passes.

3) Monotremes have a single cloaca while marsupials have separate genital and urinary tracts, although an external trace of the cloaca still exists.

4) Monotremes lack teeth; instead they chew food with bony plate at roof of mouth (echidna) or roughened gums (platypus). Marsupials have teeth.

Marsupials have bifid reproductive organs while monotremes do not.Bifid – split into 2

6) Outer ear of monotremes lack pinna (ear lobe) while marsupials have pinna.

Monotremes have reptilian/birdlike characteristics (especially in platypus) while marsupials closely resemble the other mammals.