The Unique Australian Wildlife

Many countries have their own unique fauna.
But Australia is mostly unusual in that

320-270 million years ago
Permo-Carboniferous Age
If we had observed
the Earth surface
from space at that time,
we would have seen
quite the other picture

270-210 million years ago
The end of Permian – the beginning of Trias
About 275 million years ago
Euroamerica and Angara
made a huge landmass of
Laurasia
Laurasia
The Tethys Sea
Separated Laurasia
from the protocontinent
of Pangaea
Pangaea
The Tethys Sea
Nowadays it is
the Middeteranian Sea

270-210 million years ago
The end of Permian – the beginning of Trias
On land the vertebrates are represented in the Triassic by amphibians and reptiles.
The first true mammals, which were very small, are supposed to appear in the Late Triassic.

Triassic Period:
continents and oeans of the Earth in Early Triassic time

Monotreme
The egg-laying
mammalians include
the amphibious platypus
and the terrestrial echidnas
of Australia, Tasmania,
and New Guinea
short-beaked echidna
amphibious platipus

180 million years ago
Middle Jurassic period
The protocontinent
supposedly covered
about half the Earth
and was completely
surrounded
by a world ocean
called Panthalassa.

180 million years ago
Middle Jurassic period
Dinosaurs and other reptiles emerged to dominate the land, sea, and sky.
The first birds and new varieties of reefbuilding and other invertebrate faunas, provided Jurassic life with added complexity.

Late Jurassic Epoch:
geochronological map

100 million years ago
Early Cretaceous Period
Later Pangaea began
to break apart.
Its segments Laurasia
and Gondwanaland
gradually receded,
resulting
in the formation
of the Atlantic Ocean.

Two important groups of modern
mammals evolved
during the Cretaceous.
100 million years ago
Early Cretaceous Period
Cretaceous placentals, smaller than those
of present-day ones, were poised to take over
the terrestrial environments
as soon as the dinosaurs vanished.

100 million years ago
Early Cretaceous Period
Another
mammal group,
the marsupials,
evolved during
the Cretaceous
as well.
This group includes
the native species
of Australia,
kangaroos, koalas,
and the North
American
opossum.

Late Cretaceous Epoch:
geochronological map

70 million years ago
The end of Cretaceous Period
The Late Cretaceous
record is much
more complete.
It is known, for instance,
that during the Late
Cretaceous
many dinosaur types
lived in relationships
like the present-day
terrestrial mammals.

Diprotodon
characterized by
a wombat-like body
the size of a large
rhinoceros.
massively constructed
skeleton to support
its imposing bulk.
well developed teeth
of gnawing animals.
herbivorous
distantly related
to kangaroos and
wombats.
extinct marsupial mammals
existed 30 - 10,000 years ago
in Australia.

45 million years ago
The beginning of Cenozoic era
By that time
Australasia was isolated
from all other
continental masses,
here marsupials evolved
into many diverse forms.
In South America
they survived
alongside placentals,
forming the Neotropical
mammalian fauna.

Structural and behavioral parallels with placental mammals
are in some cases quite striking.

There are marsupials that look remarkably like moles, shrews, squirrels, mice, dogs, and hyenas.

The koala and the kangaroo
are the most well-known
marsupials.

Marsupials
Long-nosed
bandicoot
Spotted-tailed
quoll,
or native cat

Marsupials
Virginia,
or opossum

Marsupials
Red kangaroo –
Wallaby
Western grey kangaroo

Marsupials
Dunnart,
a marsupial mouse
Kangaroo Rat

Marsupials
Wombat
Tasmanian Devil

Marsupials
The niches that marsupials fill
are closely associated
with structure.
The diets of marsupials
are as varied
as the niches they occupy.

The burrowing species have powerful foreclaws with which they can tunnel into the ground for food and for shelter
The gliders
have a membrane
along either flank,
attached to the forelegs
and hind legs,
that enables the animals
to glide down from a high perch

Cenozoic Era:
faunal migration routes and barriers

The earliest isolation of Australia from all the other continents made its fauna unique