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Evolution Of The Australian Biota: The Paljara Tirarense & The Sugar Glider Evolution Of The Australian Biota: The Paljara Tirarense & The Sugar Glider The Paljara Tirarense The Paljara Tirarense The Paljara tirarense was a small ringtail possum (family Pseudocheiridae) from the early Miocene of South Australia and northwestern Queensland and belonged to the Oligocene Epoch era. Ringtail possums were once much more diverse than they are today, distributed across many now-dry parts of Australia that were once forested during the Cenozoic (“the time when continents moved into their present positions. The climate started warm, but global cooling continued steadily, and finally ice ages occurred. It was the era of mammals, birds and flowering plants and aquatic mammals took over the roles of predatory reptiles.”) The distribution of The Paljara Tirarense population was scattered amoung Lake Ngapakaldi in the Tirari Desert, South Australia; and the Riversleigh World Heritage Fossil Site in northwestern Queensland. The Riversleigh area from the early to middle Miocene was mainly woodland, with open areas near forest edges and freshwater streams or lakes in a limestone environment. At Riversleigh, Paljara tirarense co-existed with several other species of ringtail. Their second habitat, The Tirari Desert was composed of shrub lands, and the sparsely vegetated dune fields (which would become covered by a carpet of grasses, herbs and colourful flowering plants following rains). Ringtail possums are ‘arboreal folivores’, meaning that they mainly feed on the leaves of trees as well as on fruits, flowers, and (in smaller species) mosses and lichens. Leaves do not provide an energy-rich diet, and pseudocheirids have efficient digestive systems to cope with the large quantities of leaves ingested.  Being apart of the marsupial family, The Paljara would have had tiny, hairless young that developed to maturity in a pouch after birth. Like other ringtail possums, The Paljara would have spent its life in the trees, feeding at night and probably building a nest of leaves to sleep in by day. Ringtail possums preyed upon by predators, many of which are known from both the Tirari Desert and Riversleigh fossil sites (marsupial 'lions', thylacines and at least one species of large raptor). The holotype of Paljara tirarense is a lower jaw from the Leaf Locality, Lake Ngapakaldi, South Australia. Other fossils found from this site include other isolated lower jaws and teeth. The Lake Ngapakaldi fossil is held by the South Australian Museum in Adelaide. Additional fossils The P. tirarense were found at the Riversleigh World Heritage Fossil Site in northwestern Queensland, and are held by the Queensland Museum, Brisbane. The family Pseudocheiridae includes the ringtail possums and greater gliders. Most members of the family are found in the rainforests or wet sclerophyll forests of northern Australia and New Guinea, although pseudocheirids can be found in a range of other environments and regions. Ringtail possums were once a much more diverse group than they are today. Fossil ringtails are known from central Australia (the Lake Eyre region) and from Riversleigh in Queensland, where there were at least 18 species in five genera. Species: tirarense Genus: Paljara Family: Pseudocheiridae Order: Diprotodontia Class: Mammalia Series: Amniota Superclass: Tetrapoda Subphylum: Vertebrata Phylum: Chordata Kingdom: Animalia The Sugar Glider The Sugar Glider The sugar glider (scientific name: Petaurus breviceps) is a small gliding possum originating from the marsupial Infraclass. The sugar glider is native to eastern and northern mainland Australia (as well as being introduced to Tasmania) and is also native to New Guinea and the Bismarck Archipelago. Map of the world, displaying the distribution of wild, captive sugar gliders as well as the overlapping of the both. They are nocturnal, meaning they sleep in their nests during the day and are active at night. This allows them to ‘safely’ gather food, steering clear of predators that are active during the day, as well as the fact that they are small, allows them to be active without being easily caught. At night, they hunt for insects and small vertebrates and feed on gum and sap (typically from the eucalyptus), acacia trees, nectar and pollen, manna and honeydew and a wide variety of arachnids. The sugar glider is named for its fondness for nectarous foods and its ability to glide through the air, much like a flying squirrel. During the different changes in the environment whereby there is a decrease in food supply, (such as; the cold season, drought, or rainy nights) a sugar glider's activity is reduced. This is usually seen due to torpor, which is “the state of decreased physiological activity in an animal, usually characterized by a reduced body temperature and rate of the metabolism”. When there is a decrease in food supply, it is a challenge for this marsupial because of the energy cost for the maintenance of its metabolism and locomotion. With energetic restraints, the sugar glider will enter into daily torpor for 2–23 hours while in rest phase. However, before entering torpor, a sugar glider will reduce activity and body temperature normally in order to lower energy expenditure and avoid torpor. Unlike many native Southern Australian animals, particularly smaller ones, the sugar glider is not endangered. Despite the massive loss of natural habitat in Australia over the last 200 years, it is adaptable and capable of living in surprisingly small patches of vestige bush, particularly if it does not have to cross-large expanses of deforested land to reach them. The sugar glider is protected by law in South Australia, where it is illegal to keep them without a permit or to capture or sell them without a license (which is usually only issued for research). Around the world, the sugar glider is a popular domestic pet, but is one of the most commonly traded wild animals in the illegal pet trade, where animals are plucked directly from their natural habitats. In Australia, sugar gliders can be kept in Victoria, South Australia and the Northern Territory but not Western Australia, New South Wales, the Australian Capital Territory, or Tasmania. Sugar gliders are popular as pets in the United States, where they are bred in large numbers. Most states and cities allow sugar gliders as pets, with some exceptions including California, Hawaii, Alaska, Pennsylvania, Massachusetts and Minnesota The sugar glider has a number of threats, both due to human activities and natural causes, such as feral predators such as cats, foxes, and dogs, habitat clearing and habitat fragmentation. Kingdom: | Animalia | Phylum: | Chordata | Class: | Mammalia | Infraclass: | Marsupialia | Order: | Diprotodontia | Family: | Petauridae | Genus: | Petaurus | Species: | P. breviceps | Similarities & Differences : Paljara Tirarense vs The Sugar Glider Similarities & Differences : Paljara Tirarense vs The Sugar Glider Similarities | Differences | * Lived in Queensland and South Australia. (In desert and forest like habitats) * Both are nocturnal, meaning they hunt during the night and rest during the day. * Both are marsupials and develop in the mother’s pouch until maturity * Their diets consist of:, * Both are terrestrial organisms * Both belong to the Cenozonic era | * The Paljara Tirarense was an arboreal folivore, and its diet consisted of: tree leaves, fruit, bark of trees, flowers, mosses, and lichens. Whilst the Sugar Gliders’ diet consisted of insects, small vertebrates, gum, sap of specific eucalyptus trees, acacia trees, nectar, manna, honeydew, and arachnids. * The Sugar Glider was primarily hunted by ‘federal predators’; such as foxes, cats and dogs. * The Paljara Tirarense was primarily the prey of marsupial lion, Thylacines. * The Sugar Glider goes into temporary hibernation or ‘torpor’ when there is a dramatic change in the environment causing a decrease of food, which forces the glider to preserve its energy. * The Piljara Tirarense is a ringtail possum, whilst The Sugar Glider is a glider. | There could be many reasons as to why The Paljara Tirarense may have evolved into a glider. The fact that both originate from both desert and rainforest like habitats mean that they are equally well adapted to both environments. However due to climatic changes, new predators and different habitats from the past, the extinct possum evolved into various other types of possums and gliders. The ringtail possum does not possess the excess skin known as ‘patagium’, that extend from the fifth finger to the first toe, leaving it to a disadvantage. The glider could have escaped from predators by ‘gliding’ through the air for up to a minimum of 100 meters. This adaptation would have allowed the organism to move freely from tree to tree hunting and collecting its food, which by coincidence happen to be found on trees. The fact that the Sugar Glider is small allows it to glide more freely, rather than if it had the body of the ringtail possum with the patagium. Australian was once a continent below sea level, meaning that it was a moist and wet environment. However throughout the centuries and millions of years of the movement and formation of the tectonic plates, Australia began to rise from below the sea and it became much drier and humid. This forced the Paljara Tirarense to evolve into The Sugar Glider, as it was quite small and could preserve its energy when and if there was a dramatic change in the environment by going into torpor. For this reason The Sugar Gliders diet is primarily high in sugar. Bibliography Bibliography Bassarova, M., Archer, M. and Hand, S. J. 2001. New Oligo-Miocene pseudocheirids (Marsupialia) of the genus Paljara from Riversleigh, northwestern Queensland. Memoirs of the Association of Australasian Palaeontologists 25, 61-75. http://www.wildlife.org.au/wildlife/speciesprofile/mammals/gliders/sugar_glider.html http://books.google.com.au/books'id=_uVkCyspttgC&pg=PA21&lpg=PA21&dq=sugar+glider+fossils&source=bl&ots=yBkBpE3k96&sig=VfulkxegEo7u0LnoS65q78GYScs&hl=en&sa=X&ei=NQ4qULWRO-f0mAW56ICoBg&ved=0CEgQ6AEwAA#v=onepage&q=sugar%20glider%20fossils&f=false Cosmos Issue 43 http://www.plosone.org/article/info:doi/10.1371/journal.pone.0008278 The references used were reliable and very informative. They were able to inform and explain the different natures’ of both the extinct (Paljara Tirarense) and extant (The Sugar Glider) and giving a thorough and clear understanding of their habitat, diet, physiology and their relations to one another.