The oceans regressed from the Australian region, so much of the land was - well, land. As a general rule, climates during the Triassic featured warmth and seasonal rainfall. Australia doesn't appear to have been an exception. Vegetation would've done well, and Triassic coal desposits are known from the middle or late Triassic, indicating possibly that the amount of rainfall (good conditions for plant growth) increased in Australia from the early part of this period to the later parts. Generally, rainfall is thought to have been pretty low throughout the world - at least at the start of the period.

At the beginning of the Triassic, the synapsid amniotes continued to dominate the fauna of large land animals (see last section). These included the dog-headed therapsids, and an extremely important group of large land herbivores: the "dicynodonts". These creatures had long sausage-shaped bodies, big round heads which had beaks and tusks. One in particular, Lystrosaurus, was fairly common in Antarctican region, south of the Australian region of Gondwana. Kannemeyeria existed in the African and Antacrtican areas of Gondwana, and a close relative definately lived in Australia. Nearby Antarctica also hosted Kingoria, a species that had become extinct elsewhere in the world back during the Permian!

The therapsid synapsids where represented by the "cynodonts" - these lived in the Antacrtican region too, and its not impossible that they spread to the Australian region at some stage. Examples of these dog-reptile creatures include Cynognathus and Thrinaxodon. Scaloposaurids, slightly more distant relatives of the cynodonts, lived in Antarctica.

By the very end of the Triassic Period, the dicynodonts had disappeared completely, and the therapsids where reduced to small furry creatures that - 200 million years ago - became the first mammals.

Their roles were replaced by the archosaurs - a group of sauropsid amniotes (kinds of reptiles). Archosaurs include dinosaurs, flying pterosaurs, crocodiles, and several groups of extinct crocodile-dinosaur-relatives. It was these crocodile-like relatives that where important at the end of the Triassic. They included big predators with toothed box-shaped heads who roamded the land. Some groups lived in aquatic environments, and they developed heads that where shaped like modern-day crocodiles. These included the phytosaurs, who evolved their crocodile-shaped heads all on their own, seperately from the crocodiles. They died out by the Jurassic Period, but the crocodiles survived throughout the Mesozoic Era.

Tasmaniosaurus, an archosaur known as a thecodont, related to the ancestors of dinosaurs, is known from the Tasmanian region of Triassic Gondwana. Kalisuchus is known from Queensland.

Theropod and prosauropod dinosaurs are known to have existed, based on fossil prosauropods (Agrosaurus macgillivrayi, probably similar to Massospondylus which existed elsewhere), and on theropod footprints, in the Australian region during the Triassic.

The large sister group to the archosaurs are the lepidosaurs. Lepidosaurs, represented by varieties of small lizards, lived in Australian Gondwana back then.

So did procolophonians - who were related to the ox-sized pareiosaurs who existed in other areas of the world, and to the turtles. They didn't look like turtle though, procolophonians looked like small lizards, although they are from a different group than modern lizards are. Modern lizards are all lepidosaurs.

Large amphibians such as Paracyclotosaurus roamed. In fact, the big labyrinthodont amphibians were extremely common, in Australia, probably much more common than the large reptiles.

The early Jurassic of the Australian region is thought to have been humid, leading on to more rainfall later - in the middle Jurassic, and then slightly drier climates in the late Jurassic. In other parts of the world, it's thought to have become drier in the middle Jurassic, as opposed to being wetter in the Australian region.

Dinosaurs: In the Early to Mid Jurassic, "sauropods" are known to have roamed. Sauropods have long necks and tails, and included the largest land animals in the history of the planet. The cetiosaurid (a kind of sauropod) Rhoetosaurus brownei existed in the Queensland area.

Theropod tracks exist - theropods are the two-legged meat-eating dinosaurs. Footprints that might belong to the armoured plant-eating "stegosaurs" also exist from this time.

Among the amphibians, animals such as Siderops kehli roamed about.

As in the Triassic, Australia is a part of the Australian-Antarctican section of Gondwana, which strecthed from the south pole all the way north to 35 degrees south latitude, and would split off from the rest of Gondwana over the course of this period. The Western regions of Australia where probably drier than the rest, not being close to an ocean current like the East was. Its possible that rifting led to more humidity in the areas around the boundary of the Antarctican and Australian regions - i.e., the two regions started to split apart, creating a rift valley that was eventually flooded, creating a small inland sea that provides moisture to the region. And where there's moisture, there's plant growth.

Meanwhile in Europe (in the Middle Jurassic), the earliest known mammal has appeared.

The late Jurassic saw a period of global warming, resulting in a rise of sea level. By the late Jurassic/early Cretaceous, Pangea had split into Laurasia (which sported a shallow sea running down the middle of it, effectively dividing it into two continents) in the northern hemisphere, and Gondwana in the southern hemisphere - now broken into three main parts: Australia-Antarctica, India, and Africa-SouthAmerica - the latter of which almost connected with the western (North America) half of Laurasia.

In the early Cretaceous, an inland sea split the Australian region from modern-day Broom to the modern-day Great Australian Bight, cutting Western Australia from the rest of the region. Water probably lay from the East Coast inland to this aforementioned seaway, covering much of Queensland and New South Wales and connecting it to the ocean on the east, and there were likely also connections-by-sea through the north as well.

Chelonians (turtles, tortoises) arrived in the Australian area in the early Cretaceous (they had first appeared in Europe back in the Triassic). Notochelone costata, about a metre in length, with a ridge along its back, was the first known Australian turtle. It became quite common. Like most other Cretaceous Australia turtles, it was a marine animal.

A "pterosaur" is known from these times in Australia. Pterosaurs were flying archosaurs, the sister group to dinosaurs, and probably endotherms ("warm blooded" animals). They first appeared in Europe during the late Triassic period, spreading worldwide, and flourished from the beginning of the Jurassic period, and through the Cretaceous, then became extinct by the end of the Late Cretaceous. The earliest Australian pterosaur so far known is from the Early Cretaceous. This animal was probably a marine fish-eating animal, with a wingspan of about two to four metres.

Other fragments of pterosaurs have been found from Early Cretaceous Victoria.

As far as those lepidosaurs (remember - lepidosaurs include modern lizards and snakes, and are the sister group to the archosaurs (which includes dinosaurs, crocodiles and pterosaurs)) are concerned, the early Cretaceous saw the first appearance of snakes, along with an extinct group of sea-dwelling snakes called "symoliophids". These early serpents aren't known from Australia.

The lepidosaurs also developed into marine lizards - the predatory mosasaurs, a kind of squamatan (squamatan include most modern lizards). They became giants of the seas, developing large paddles from their legs. One of the only Mesozoic lepidosaurs known from Australia is a mosasaur, from the late Cretaceous. But these mosasaurs were very abundant in the region of Australia, and are well known from New Zealand. Mosasaurs were superficially similar looking to another group of huge sea-going reptiles: the pliosaurs, but were not related to them (apart from being fellow lepidosaurs).

In the early Cretaceous, the ichthyosaur Platypterygius australis (a species very similar to another form that has been found around the world), lived in the large shallow sea around Queensland, along with Notochelone. Ichthyosaurs (perhaps not exactly this species) lived across the rest of the Australian area of Gondwana also. They are lepidosaurs - not dinosaurs or even archosaurs - and they looked like dolphins or fishes, even though they were reptiles.

Another group of swimming lepidosaurs, the "sauropterygians", were abundant in Australia. Sauropterygians are a group of marine reptiles that includes the nothosaurs and the plesiosaurs, and Claudiosaurus.

They originated near Madagascar, and of the three types, only the "plesiosaurs" are known to have lived in Australia. The plesiosaurs are divided into the pliosauroids, and the plesiosauroids. Plesiosauroids (eg// the elasmosaurid Woolungasaurus glendowerensis) had long necks and small heads, whereas pliosauroids (eg// Kronosaurus queenslandicus) had short necks and almost whale-like bodies. Both were predatory. They lived worldwide, even down to polar latitudes, for probably the whole Cretaceous period.

Dinosaurs: About 124mya to 112mya, the slender theropod Kakuru kujani existed in South Australia. This theropod was not closely related to other overseas theropods. The earliest known birds of Australia date from this time, but are only known from feather impressions. Birds are really a type of theropod.

Representatives of the giant brachiosaurids - a kind of sauropod - are suspected to have lived in Australia at this time.

The nodosaurid (a kind of ankylosaurian - ankylosaurians are armoured plant-eating dinosaurs with bony "scutes" covering most of their backs) Minmi paravertebra is known from Queensland, along with traces of other ankylosaurs. Minmi is another unique animal. It posessed odd little bones (paravertebra) that strengthened the back, distuinguishing it from other nodosaurids (who lacked these). It is possible the paravertebra were nessecary to support the weight of the armour on the belly. Most ankylosaurians didn't have armour on the belly - just the back - so this also makes Minmi pretty special. Minmi lived on a large island - a large area of Queensland that was isolated from the rest of the Australian region by the inland shallow seas described above.

During the Albian stage (112-97mya), nearly all the major dinosaur groups are known to exist in Australia.

The theropods were definitely around, along with the plant-eating ornithopods - in particular, iguanodonts. The famous Muttaburrasaurus langdoni exists in this group in the early Cretaceous.

Also present are sauropods such as Austrosaurus mckillopi. Austrosaurus is similar to the cetiosaurs known from other continents, only those cetiosaurs are of Jurassic age, and Austrosaurus is of Cretaceous age.

Sheep-sized (and smaller) relatives of the iguanodonts mentioned above, the "hypsilophodonts", existed in Australia back then. In Victoria, members of this group included Leaellynasaura amicagraphica, Atlascopcosaurus loadsi, and Fulgurotherium australe. The latter of which is known to have been around since 124 or even 140 million years ago, along with other hypsilophodonts, and allosaurids. Alongside these dinosaurs, amphibian labyrinthodonts were around, as were members of the dinosaurs sister group: the flying pterosaurs.

There were also turtles - non-archosaurian reptiles related to the little extinct lizard-like procolophonians mentioned above.

The huge amphibians where still around as well - the labryinthodonts.

A theropod dinosaur of note is the poorly known Rapator ornitholestoides, of which only a metacarpal (bone in foot) is known, but an unusual metacarpal that distuinguishes this animal from other theropods. Also present were species of Allosaurus, at least six metres long (North American allosaurs were 13 metres long).

Mammals: The earliest known monotreme is from the early Cretaceous in the Australian region. Steropodon galmani, a very large platypus.

Roughly 100mya saw the warmest times during the Cretaceous - average temperature could've been about ten degrees higher than today, and naturally this coincides with a very high sea level. Higher latitudes would've been warm (Subtropical kinds of plants were present around even 55 degrees latitude), but with strong seasons, so there would've been a winter frost.

Right up untill around 97mya, the sea covered various areas of the inland of the Australian region. Then it finally withdrew.

Due to the presence of rich invertebrate faunas, its thought the Cretaceous was generally warm. Although parts of south and central Australia could have had temperatures - especially during the long winters of those latitudes - dropping to zero degrees celsius or below. Increasing amounts of rain are thought to have fallen through the period.

Around 95mya, and definately by the time 85mya roled around, the seafloor inbetween the Australian region and the Antarctican region began spreading, and the two landmasses began to split furhter apart, Australia drifting north, and Antarctica drifting south.

As for the dinosaurs, more theropods, and sauropods (including Austrosaurus), and ornithopods are known from Queensland during the late Cretaceous.

The end of the Cretaceous saw the Australian region of the Antarctica-Australia landmass begin drifting northwards. The northern African-South American part of Gondwana had meanwhile broken up into the two continents Africa and South America.

Pterosaurs are known from Late Cretaceous New Zealand.

The very late Cretaceous, is very poorly known. Australia had tropical forests covering a lot of the continent at this time. Indeterminate hypsilophodont and theropod remains are known from New Zealand.