Australia-New Guinea, also called Sahul or Meganesia, is made up of the continent of Australia and the islands of New Guinea and Tasmania. These land masses are separated by the Torres Strait (Australia and New Guinea) and the Bass Strait (Australia and Tasmania). However, from biological and geological points of view, they form a single unit. During the ice age, they formed a single continent. Motto: Ubertas et Fidelitas (Fertility and Faithfulness) Nickname: ? Other Australian states and territories Capital Hobart Government Governor Premier Const. ... The Torres Strait is the body of water which lies between Australia and Papua New Guinea. ... Bass Strait is a sea strait separating Australian mainland (Victoria in particular). ... Biology is the science of life (from the Greek words bios = life and logos = reasoned account). ... Geology (from Greek γη- (ge-, the earth) and λογος (logos, word, reason)) is the science and study of the Earth, its composition, structure, physical properties, history, and the processes that shape it. ... Variations in CO2, temperature and dust from the Vostok ice core over the last 400 000 years For the animated movie, see Ice Age (movie). ...

Australia, New Guinea, and Tasmania all sit on top of a single tectonic plate, the Indo-Australian Plate, and are connected by a shallow continental shelf. All were joined onto Antarctica as part of the southern supercontinent Gondwana until the plate began to drift north about 96 million years ago (mya). For most of the time since then Australia-New Guinea has remained a single landmass. Categories: Geology stubs | Plate tectonics ... Categories: Plate tectonics | Geology stubs ... The continental shelf is the extended perimeter of each continent, which is covered during interglacial periods such as the one we live in by relatively shallow seas and gulfs. ... This article is about the ancient supercontinent of Gondwana. ... Mya has more than one meaning: Mya, an American R&B singer. ...

As the continent drifted north, a unique flora and fauna developed. Marsupials and monotremes also existed on other continents, but only in Australia-New Guinea did they out-compete the placental mammals and come to dominate. Bird life also flourished, in particular the ancestors of the great passerine order that would eventually spread to all parts of the globe and account for more than half of all living avian species. Flora is a collective term for plant life. ... Fauna is a collective term for animal life. ... Orders Superorder Ameridelphia Didelphimorphia Paucituberculata Superorder Australidelphia Microbiotheria Dasyuromorphia Peramelemorphia Notoryctemorphia Diprotodontia Family Thylacinidae (extinct) Marsupials are mammals in which the female typically has a pouch (called the marsupium, from which the name Marsupial derives) in which it rears its young through early infancy. ... Families Kollikodontidae (extinct) Ornithorhynchidae - Platypus Tachyglossidae - Echidnas Steropodontidae (extinct) Monotremes are mammals that are best known for laying eggs, instead of giving birth to live young like marsupials and placental mammals (Eutheria). ... Orders Afrosoricida Macroscelidea Tubulidentata Hyracoidea Proboscidea Sirenia Xenarthra Dermoptera: Scandentia Primates Rodentia Lagomorpha Insectivora Chiroptera Pholidota Carnivora Perissodactyla Artiodactyla Cetacea Placentalia and Eutheria are terms used to describe major groupings within the animal class of Mammalia. ... Orders Subclass Monotremata Monotremata Subclass Marsupialia Didelphimorphia Paucituberculata Microbiotheria Dasyuromorphia Peramelemorphia Notoryctemorphia Diprotodontia Subclass Placentalia Xenarthra Dermoptera Desmostylia Scandentia Primates Rodentia Lagomorpha Insectivora Chiroptera Pholidota Carnivora Perissodactyla Artiodactyla Cetacea Afrosoricida Macroscelidea Tubulidentata Hyracoidea Proboscidea Sirenia The mammals are the class of vertebrate animals primarily characterized by the presence of mammary... For other meanings of bird, see bird (disambiguation). ... Families Many, see text A passerine is a bird of the giant order Passeriformes. ... In biology, a species is a kind of organism. ...

There were three main reasons for the enormous diversity that developed in both plant and animal life.

• While much of the rest of the world underwent significant cooling and thus loss of species diversity, Australia-New Guinea was drifting north at such a pace that the overall global cooling effect was roughly equalled by its gradual movement toward the equator. Temperatures in Australia-New Guinea, in other words, remained reasonably constant for a very long time, and a vast number of different plant and animal species were able to evolve to fit particular ecological niches.
• Because the continent was more isolated than any other, very few outside species arrived to colonise, and unique native forms developed unimpeded.
• Finally, the continent was already very old and thus relatively infertile. Where other continents had volcanic activity and/or massive glaciation events to turn over fresh, un-leached rocks rich in minerals, the rocks and soils of Australia-New Guinea were left largely untouched except by gradual erosion and deep weathering. In general, fertile soils produce a profusion of life, but only a relatively small number of species. This is because where nutrients are plentiful, competition is largely a matter of absorbing them as fast as possible. In contrast, infertile soils tend to produce a great variety of species, each one specialised for a particular niche: a single plant species, for example, can rapidly develop into several different but related species: one that specialises in slightly acid conditions, another that colonises dryer places, and so on.

For about 40 million years Australia-New Guinea was almost completely isolated. During this time, the continent experienced numerous changes in climate, but the overall trend was towards greater aridity. When South America eventually separated from Antarctica, the development of the cold Antarctic Circumpolar Current changed weather patterns across the world. For Australia-New Guinea, it brought a marked intensification of the drying trend. The great inland seas and lakes dried out. Much of the long-established broad-leaf deciduous forest began to give way to the distinctive hard-leaved sclerophyllous plants that characterise the modern Australian landscape. The equator is an imaginary line drawn around a planet, halfway between the poles. ... Temperature is the physical property of a system which underlies the common notions of hot and cold; the material with the higher temperature is said to be hotter. ... Generally, a niche is a special place within the scheme of things. ... This article is about volcanoes in geology. ... Austrias longest glacier, the Pasterze, winds its 8 km (5 mile) route at the foot of Austrias highest mountain, the Grossglockner. ... Sedimentary, volcanic, plutonic, metamorphic rock types of North America. ... Minerals are natural compounds formed through geological processes. ... For the heavy metal band see Soil (band) Soil is the layer of minerals and organic matter, in thickness from centimetres to a metre or more, on the land surface. ... Severe soil erosion in a wheat field near Washington State University, USA. Erosion is the displacement of solids (soil, mud, rock, and so forth) by the agents of wind, water, ice, movement in response to gravity, or living organisms (in the case of bioerosion). ... Weathering is the process of decomposition and/or disintegration of rocks in situ, that is, in place. ... Nutrients and the body A nutrient is any element or compound necessary for or contributing to an organisms metabolism, growth, or other functioning. ... An acid (often represented by the generic formula AH) is typically a water-soluble, sour-tasting chemical compound. ... South America South America is a continent crossed by the equator, with most of its area in the Southern Hemisphere. ... The Antarctic Circumpolar Current (ACC) is an ocean current that flows from west to east around Antarctica. ... Deciduous forest after leaf fall Deciduous means temporary or tending to fall off (deriving from the Latin word decidere, to fall off). ... Arid, largely treeless areas aside, most Australian bushland is sclerophyll forest. ...

For many species, the primary refuge was the relatively cool and well-watered Great Dividing Range. Even today, pockets of remnant vegetation remain in the cool uplands, some species not much changed from the Gondwanan forms of 60 or 90 mya. The Great Divide runs around the entire eastern and south-eastern edge of Australia The Great Dividing Range is Australias only substantial mountain range. ...

Eventually, the Australia-New Guinea tectonic plate collided with the Eurasian plate to the north. The collision caused the northern part of the continent to buckle upwards, forming the high and rugged mountains of New Guinea and, by reverse (downwards) buckling, the Torres Strait that now separates the two main landmasses. The collision also pushed up the islands of Wallacea, which served as island 'stepping-stones' that allowed plants from Southeast Asia's rainforests to colonise New Guinea, and some plants from Australia-New Guinea to move into Southeast Asia. The ocean straits between the islands were narrow enough to allow plant dispersal, but served as an effective barrier to exchange of land mammals between Australia-New Guinea and Asia. Categories: Plate tectonics | Geology stubs ... Wallacea is a biogeographical designation for a group of Indonesian islands separated by deep water from the Asian and Australian continental shelves. ... Location of Southeast Asia Southeast Asia is a subregion of Asia. ...

Although New Guinea is the most northerly part of the continent, and could be expected to be the most tropical in climate, the altitude of the New Guinea highlands is such that a great many animals and plants that were once common across Australia-New Guinea now survive only in the tropical highlands (where they are severely threatened by overpopulation pressures). World population increase. ...

See also

• Plate tectonics
• Paleoclimatology
• Biogeography