Australian megafauna

Australian megafauna are a number of large animal species in Australia, often defined as species with body mass estimates of greater than 30 kilograms, or equal to or greater than 30% greater body mass than their closest living relatives. Many of these species became extinct during the Pleistocene (16,100±100 - 50,000 years before present).^[1]

The cause of the extinction is an active and contentious field of research. It is hypothesised that with the arrival of humans (around 48,000-60,000 years ago), hunting and the use of fire to manage their environment may have contributed to the extinction of the megafauna.^[2] Increased aridity during peak glaciation (about 18,000 years ago) may have also contributed to the extinction of the megafauna. Some proponents claim a change in the climate alone caused extinction of the megafauna, but these arguments have to account for the fact that megafaunal species comfortably survived two million years of climatic oscillations, including a number of arid glacial periods, before their sudden extinction.

New evidence based on accurate optically stimulated luminescence and uranium-thorium dating of megafaunal remains suggests that humans were the ultimate cause of the extinction of megafauna in Australia.^[3] The dates derived show that all forms of megafauna became extinct in the same rapid timeframe — approximately 46,000 years ago^[4] — the period of time in which humans first arrived in Australia. Analysis of oxygen and carbon isotopes from teeth of megafauna indicate the regional climates at the time of extinction were similar to arid regional climates of today, and that the megafauna were well adapted to arid climates.^[3] The dates derived have been interpreted as suggesting that the main mechanism for extinction was human burning of a landscape that was then much less fire-adapted; oxygen and carbon isotopes of teeth indicate sudden, drastic, non-climate-related changes in vegetation and in the diet of surviving marsupial species. However, humans appear to have rapidly eliminated the megafauna of Tasmania about 41,000 years ago (following formation of a land bridge to Australia about 43,000 years ago as ice age sea levels declined) without using fire to modify the environment there,^[5][6][7] implying that at least in this case hunting was the most important factor. It has also been suggested that the vegetational changes that occurred on the mainland were a consequence, rather than a cause, of the elimination of the megafauna.^[5]

There are similarities between prehistoric Australian megafauna and some mythical creatures from the aboriginal dreamtime (Mackness 2009).

Contents 1 Living Australian megafauna 1.1 Mammals 1.2 Birds 1.3 Reptiles 1.4 Bony fish 1.5 Cartilaginous fish 1.6 Mollusks 2 Extinct Australian megafauna 2.1 Monotremes 2.2 Marsupials 2.2.1 1,000-2,000 kilograms[11] 2.2.2 100-1,000 kilograms 2.2.3 10-100 kilograms 2.3 Birds 2.4 Reptiles 3 See also 4 References 5 External links

Living Australian megafauna

The term "megafauna" is usually applied to large animals (over 100 kg) that went extinct in the Pleistocene, roughly 60,000 years ago. In Australia, however, the megafauna were never as large as those found on other continents and so a more lenient criteria of over 40 kg is often applied^[8]

Mammals

• Red Kangaroo (Macropus rufus) This species is a very large kangaroo with short, red-brown fur, fading to pale buff below and on the limbs. It has long, pointed earlobes and a squared-off muzzle. Females are smaller than males and are blue-grey with a brown tinge, pale grey below, although arid zone females are coloured more like males. It has two appendages with small claws (much like arms), two muscular legs, which are used for jumping, and a tail, which is often used like a third leg for balance.

Red Kangaroos' legs work much like a rubber band. The male Red Kangaroo can leap in full force approximately 30 feet (9.14 m) in one leap. Males grow up to 1.8m (6ft) tall and weigh up to 85 kg (187lbs). Females grow up to 1.1m (3.6ft) tall and weigh up to 35kg (77lbs). Tails can be up to 1m (3ft) along.

• Eastern Grey Kangaroo (Macropus giganteus) is a marsupial found in southern and eastern Australia, with a population of several million. Although a big Eastern Grey male typically weighs around 66 kg (145 lb) and stands almost 2 m (6 ft.) tall, the scientific name, Macropus giganteus (gigantic large-foot), is misleading, as the Red Kangaroo of the semi-arid inland is larger.

• Antilopine Kangaroo (Macropus antilopinus), sometimes called the Antilopine Wallaroo or the Antilopine Wallaby, is a species of macropod found in northern Australia: in Cape York Peninsula in Queensland, the Top End of the Northern Territory, and the Kimberley region of Western Australia. It is a locally common, gregarious grazer.^[9]

• Eastern Wallaroo (Macropus robustus), also called the Hill Wallaroo, is generally found in a variety of habitats; forests, deserts, and grasslands. They can weigh as much as 15–47 kg (33-105 lb) and grow over 4 feet long.

• Common Wombat (Vombatus ursinus), among the three species of wombat, this variety can get to be 25–40 kg (55-88 lb). Common wombats thrive in Eastern Australia and Tasmania, and prefer temperate forests and highland regions.

• Southern Hairy-nosed Wombat (Lasiorhinus latifrons), among the three species of wombat, they only get to be 19–32 kg (42-71 lb). They are much stockier then the Common Wombat and have much shorter limbs.

• Dingo (Canis lupus dingo), a subspecies of wolf (to be precise a variant of the domestic dog) that was introduced into the continent around 4000 years ago most likely by Asian seafarers and later returned to the wild. The average weight of a dingo is about 13–20 kg, although heavier dogs can be found. Most are found in mainland Australia, yet many can be found in Thailand.^[10]

Birds

• Emu The emu was first described under the name of the New Holland Cassowary in Arthur Phillip's Voyage to Botany Bay, published in 1789.[4] The species was named by ornithologist John Latham, who collaborated on Phillip's book and provided the first descriptions of and names for many Australian bird species; its name is Latin for "fast-footed New Hollander". The etymology of the common name Emu is uncertain, but is thought to have come from an Arabic word for large bird that was later used by Portuguese explorers to describe the related Cassowary in New Guinea.[5] In Victoria, some terms for the emu included Barrimal in the Djadja wurrung language, myoure in Gunai, and courn in Jardwadjali.[6]

In his original 1816 description of the emu, Vieillot used two generic names; first Dromiceius, then Dromaius a few pages later. It has been a point of contention ever since which is correct; the latter is more correctly formed, but the convention in taxonomy is that the first name given stands, unless it is clearly a typographical error.[7] Most modern publications, including those of the Australian government,[8] use Dromaius, with Dromiceius mentioned as an alternative spelling.

• Cassowary The Northern and Dwarf Cassowaries are not well known. Cassowaries are usually shy, secretive birds of the deep forest, adept at disappearing long before a human knows they are there. Even the more accessible Southern Cassowary of the Queensland rain forests is not well understood.

Reptiles

• Goanna

Being predatory lizards, goannas are often quite large, or at least bulky, with sharp teeth and claws. The largest is the Perentie (Varanus giganteus), which can grow over 2 m in length. They prey on all manner of small animals; insects, lizards, snakes, mammals, birds, and eggs. Meals are often eaten whole, and thus the size of their meals depends on the size of the animal itself. However, the Perentie has been observed killing a young kangaroo, and then biting out chunks of flesh like a dog. Goannas have even been blamed for the death of sheep by farmers, though most likely erroneously, as goannas are also eaters of carrion and are attracted to rotting meat.

Not all goannas are gargantuan. Pygmy goannas may be smaller than a man's arm. The smallest of these, the short-tailed monitor (Varanus brevicuda) reaches only 20 cm in length. They survive on smaller prey such as insects and mice.

• Saltwater Crocodile

A healthy adult male saltwater crocodile is typically 4.8 to 7 metres (15.75 to 21.6 ft) long, and weighs up to 770 kg (1697 lb), with many exceptions being much larger than this. Many large sizes have been reported^[1] [2], [1] Females are much smaller than males, with typical female body lengths in the range of 2.5–3 meters. A 28 foot (8.5 m) individual was reportedly shot on the Norman River of Queensland in 1957 and a cast was made of this animal (which can be viewed and is quite the popular tourist attraction), but due to the time since the occurrence and lack of rock hard evidence (other than the plaster) it is not considered "official". The saltwater crocodile has fewer armor plates on its neck than other crocodilians, and its broad body contrasts with most other lean crocodiles, leading to early unverified assumptions the reptile was an alligator.[2]Crocodylus porosus (Schneider, 1801), by Adam Britton from the Crocodilian Species List. The saltwater crocodile is the largest extant native animal in Australia that spends any portion of its time on land.

• Freshwater Crocodile

Bony fish

• Queensland Lungfish (Neoceratodus forsteri)

Fossil records of this group date back 380 million years, around the time when the higher vertebrate classes were beginning to evolve. Fossils of lungfish almost identical to this species have been uncovered in northern New South Wales, indicating that Neoceratodus has remained virtually unchanged for well over 100 million years, making it one of the oldest living vertebrate genera on the planet.

The Queensland Lungfish is one of six extant representatives of the ancient air-breathing Dipnoi (lungfishes) that flourished during the Devonian period (c. 413-365 million years ago) and is the most primitive surviving member of this lineage. The five other freshwater lungfish species, four in Africa and one in South America, are very different morphologically to N. forsteri. The Queensland lungfish can live for several days out of the water, if it is kept moist, but will not survive total water depletion, unlike its African counterparts.[1]

• Gulf Saratoga (Scleropages jardinii)

Scleropages jardinii is a freshwater bony fish native to Australia, one of two species of fishes sometimes known as Australian arowanas, the other being the Saratoga (S. leichardti). It has numerous other common names, including northern saratoga, Australian bonytongue, toga and barramundi (not to be confused with the barramundi perch, Lates calcarifer). It is a member of the subfamily Osteoglossinae, a (basal) teleost group. Its scientific name is sometimes erroneously spelled S. jardini.

Cartilaginous fish

• Southern Shovelnose Ray (Aptychotrema vincentiana)

The southern shovelnose ray, also known as the western shovelnose ray or the yellow shovelnose ray, is a species of fish in the Rhinobatidae family. It is endemic to Australia. Its natural habitats are open seas and shallow seas.

Mollusks

• Australian Giant Cuttlefish

Sepia apama, is the world's largest cuttlefish species, growing to 50 cm in mantle length and over 10.5 kg (23 lb) in weight.[1] S. apama is native to the southern coast of Australia, from Brisbane in Queensland to Shark Bay in Western Australia. It occurs on rocky reefs, seagrass beds, and sand and mud seafloor to a depth of 100 m.[2]

• Southern Sand Octopus

is an octopus native to the waters around the Great Australian Bight and Tasmania [2]. It has an arm span of up to 50 centimetres (20 in) with long, unusually thin tentacles joined at the base by webbing and studded with small suckers. Like most octopuses, it can change shape and colour, and is often hard to spot as it spends day buried in the sand, preferring to venture out for food at night.

Extinct Australian megafauna

The following is an incomplete list of extinct Australian megafauna (monotremes, marsupials, birds and reptiles) in the format:

• Latin name, (common name, period alive), and a brief description.

Monotremes

Monotremes are arranged by size with the largest at the top.

• Zaglossus hacketti was a sheep-sized echidna uncovered in Mammoth Cave in Western Australia, and is the largest monotreme so far uncovered.
• Obdurodon dicksoni was a platypus up to 60 cm in total length, fossils of which were found at Riversleigh.
• Megalibgwilia ramsayi was a large, long-beaked echidna with powerful forelimbs for digging. Its diet would probably have included worms and grubs rather than ants.
• Megalibgwilia robusta was a long-beaked echidna.

Marsupials

Marsupials are arranged by size with largest at the top.

1,000-2,000 kilograms^[11]

• Diprotodon optatum was the largest species of diprotodontid. Approximately three metres long, two metres high at the shoulder and weighing up to two tonnes, it resembled a giant wombat. It is the largest marsupial currently known.
• Zygomaturus trilobus was a smaller (bullock-sized, about two metres long by one metre high) diprotodontid that may have had a short trunk. It appears to have lived in wetlands, using two fork-like incisors to shovel up reeds and sedges for food.
• Palorchestes azael (the Marsupial Tapir) was a diprotodontoid similar in size to Zygomaturus, with long claws and a longish trunk. It lived in the Pleistocene (Mackness 2009).

100-1,000 kilograms

• Euowenia grata
• Euryzygoma dunense
• Phascolonus gigas
• Ramsayia magna
• Procoptodon goliah (the Giant Short-faced Kangaroo) is the largest kangaroo to have ever lived. It grew 2–3 metres (7–10 feet) tall, and weighed up to 230 kilograms. It had a flat shortened face with jaw and teeth adapted for chewing tough semi-arid vegetation, and forward-looking eyes providing stereoscopic vision. Procoptodon was one of seventeen species in three genera in the sthenurine subfamily, of whom all are extinct. Sthenurines inhabited open woodlands in central Northern Australia as the tropical rainforests were beginning to retreat. All sthenurines had an extremely developed, almost hoof-like, fourth toe on the hindlimbs, with other toes vestigial. Additionally, elastic ligaments between the toe bones gave this group improved spring and speed compared to modern kangaroos. Sthenurine forelimbs were long with two extra-long fingers and claws compared with the relatively small, stiff arms of modern macropods. These may have been used for pulling branches nearer for eating and for quadrupedal movement for short distances.
• Procoptodon rapha, P. pusio and P. texasensis
• Protemnodon a form of giant wallaby with 4 species.^[12]
• Palorchestes parvus
• Macropus pearsoni and M. ferragus

10-100 kilograms

• Simosthenurus pales
• Sthenurus tindalei and S. atlas
• Phascolarctos stirtoni was a koala similar to the modern form, but one third larger.
• Phascolomys medius
• Lasiorhinus angustioens
• Thylacine (Tasmanian Tiger)
• Congruus congruus a wallaby from Naracoorte.
• Troposodon minor
• Sthenurus oreas
• Simosthenurus occidentalis (another sthenurine) was about as tall as a modern Eastern Grey Kangaroo, but much more robust. It is one of the nine species of leaf-eating kangaroos identified in fossils found in the Naracoorte Caves National Park.
• Simothenurus brownei
• Propleopus oscillans (the Carnivorous Kangaroo), from the Miocene and Pliocene epochs, was a large (~70 kilogram) rat-kangaroo with large shearing and stout grinding teeth that indicate it may have been an opportunistic carnivore able to eat insects, vertebrates (possibly carrion), fruits, and soft leaves. Grew to about 1.5 – 3 metres in height.
• Simothenurus maddocki
• Sthenurus andersoni
• Thylacoleo carnifex, (the Marsupial Lion), was the size of a leopard, and had a cat-like skull with large slicing pre-molars. It had a retractable thumb-claw and massive forelimbs. It was almost certainly carnivorous and a tree-dweller.
• Vombatus hacketti
• Macropus thor
• Macropus piltonensis
• Macropus rama
• Simothenurus gilli
• Warrendja wakefieldi a wombat from Naracoorte.
• Sarcophilus harrisii laniarius was a large form of the Tasmanian Devil.

Birds

• Family Dromornithidae: this group of birds was more closely related to waterfowl than modern ratites.
  • Dromornis stirtoni, (Stirton's Thunder Bird, Miocene epoch) was a flightless bird three metres tall that weighed about 500 kilograms. It is one of the largest birds so far discovered. It inhabited subtropical open woodlands and may have been carnivorous. It was heavier than the moa and taller than Aepyornis.
  • Bullockornis planei (the 'Demon Duck of Doom') was another huge member of the Dromornithidae. It was up to 2.5 metres tall and weighed up to 250 kilograms, and was probably carnivorous.
  • Genyornis newtoni (the Mihirung) was related to Dromornis, and was about the height of an ostrich. It was the last survivor of the Dromornithidae. It had a large lower jaw and was probably omnivorous.
• Leipoa gallinacea (formerly Progura) was a giant malleefowl.

Reptiles

• Varanus priscus (formerly Megalania prisca) was a giant, carnivorous goanna that might have grown to as long as 7 metres (23 feet), and weighed up to 1,940 kilograms (Molnar, 2004).
• Wonambi naracoortensis was a non-venomous snake of five to six metres in length, an ambush predator at waterholes which killed its prey by constriction.
• Quinkana sp., was a terrestrial crocodile which grew from five to possibly 7 metres in length. It had long legs positioned underneath its body, and chased down mammals, birds and other reptiles for food. Its teeth were blade-like for cutting rather than pointed for gripping as with water dwelling crocodiles. It belonged to the mekosuchine subfamily (all now extinct). It was discovered at Bluff Downs in Queensland.
• Liasis sp., (Bluff Downs Giant Python), lived during the Pliocene epoch, grew up to ten metres long, and is the largest Australian snake known. It hunted mammals, birds and reptiles in riparian woodlands. It is most similar to the extant Olive Python (Liasis olivacea).^[13]
• Meiolania was a genus of huge terrestrial cryptodire turtle measuring 2.5 m (8 ft 4 inches) in length, with a horned head and spiked tail.

See also

• Mammoth Cave
• Naracoorte Caves National Park
• Riversleigh

References

1. ^ ^{a b} Vanderwal and Fullager 1989 as cited in Josephine Flood (2004) Archaeology of the Dreamtime, J.B Publishing, Marleston p, 182 ISBN 1-876-62250-4
2. ^ Miller, G. H. (2005). "Ecosystem Collapse in Pleistocene Australia and a Human Role in Megafaunal Extinction". Science 309: 287–290. doi:10.1126/science.1111288. PMID 16002615. 
3. ^ ^{a b} Prideaux, G. J.; Long, J. A.; Ayliffe, L. K.; Hellstrom, J. C.; Pillans, B.; Boles, W. E.; Hutchinson, M. N.; Roberts, R. G.; Cupper, M. L.; Arnold, L. J.; Devine, P. D.; Warburton, N. M. (2007-01-25). "An arid-adapted middle Pleistocene vertebrate fauna from south-central Australia". Nature 445 (7126): 422–425. doi:10.1038/nature05471. PMID 17251978. http://www.nature.com/nature/journal/v445/n7126/abs/nature05471.html. Retrieved 2011-08-26. 
4. ^ Roberts, R. G.; Flannery, T. F.; Ayliffe, L. K.; Yoshida, H.; Olley, J. M.; Prideaux, G. J.; Laslett, G. M.; Baynes, A.; Smith, M. A.; Jones, R.; Smith, B. L. (2001-06-08). "New Ages for the Last Australian Megafauna: Continent-Wide Extinction About 46,000 Years Ago". Science 292 (5523): 1888–1892. doi:10.1126/science.1060264. PMID 11397939. http://www.uow.edu.au/content/groups/public/@web/@sci/@eesc/documents/doc/uow014698.pdf. Retrieved 2011-08-26. 
5. ^ ^{a b} Diamond, Jared (2008-08-13). "Palaeontology: The last giant kangaroo". Nature 454 (7206): 835–836. doi:10.1038/454835a. PMID 18704074. http://www.nature.com/nature/journal/v454/n7206/full/454835a.html. Retrieved 2011-05-08. 
6. ^ Turney, C. S. M.; Flannery, T. F.; Roberts, R. G.; et al. (2008-08-21). "Late-surviving megafauna in Tasmania, Australia, implicate human involvement in their extinction". PNAS (NAS) 105 (34): 12150–12153. doi:10.1073/pnas.0801360105. PMC 2527880. PMID 18719103. http://www.pnas.org/content/early/2008/08/20/0801360105.abstract. Retrieved 2011-05-08. 
7. ^ Roberts, R.; Jacobs, Z. (2008-10). "The Lost Giants of Tasmania". Australasian Science 29 (9): 14–17. http://www.control.com.au/bi2008/299megafauna.pdf. Retrieved 2011-08-26. 
8. ^ Danielle Clode (2009) Prehistoric giants: the megafauna of Australia, Museum Victoria ISBN 9780980381320
9. ^ Menkhorst, Peter (2001). A Field Guide to the Mammals of Australia. Oxford University Press. p. 110. 
10. ^ "Dingo" (PDF). http://www.canids.org/species/Dingo.pdf. Retrieved 2011-07-24. 
11. ^ Flannery. T Pleistocene extinctions as cited in Josephine Flood (2004) Archaeology of the Dreamtime, J.B Publishing, Marleston p. 178 ISBN 1-876-62250-4
12. ^ Helgen, K.M.; Wells, R.T.; Kear, B.P.; Gerdtz, W.R.; Flannery, T.F. (2006). "Ecological and evolutionary significance of sizes of giant extinct kangaroos". Australian Journal of Zoology 54: 293–303. doi:10.1071/ZO05077. 
13. ^ Scanlon, JD; Mackness, BS. (2001). "A new giant python from the Pliocene Bluff Downs Local Fauna of northeastern Queensland". Alcheringa 25: 425–437. 

• Field, J. H.; Dodson, J. (1999). "Late Pleistocene megafauna and archaeology from Cuddie Springs, south-eastern Australia". Proceedings of the Prehistoric Society 65: 1–27. 
• Field, J. H.; Boles, W. E. (1998). "Genyornis newtoni and Dromaius novaehollandiae at 30,000 b.p. in central northern New South Wales". Alcheringa 22 (2): 177–188. doi:10.1080/03115519808619199. 
• Long, J.A., Archer, M. Flannery, T.F. & Hand, S. 2003. Prehistoric Mammals of Australia and New Guinea -100 Million Years of Evolution. Johns Hopkins University Press, Baltimore. 242pp.
• Mackness, B.S. (2009). "Reconstructing Palorchestes (Marsupialia: Palorchestidae) — from Giant Kangaroo to Marsupial 'Tapir'". Proceedings of the Linnean Society of New South Wales 130: 21–36. 
• Molnar, R. 2004. Dragons in the Dust: The Paleobiology of the Giant Lizard Megalania. Indiana University Press. Page: 127.
• Murray, P. F.; Megirian, D. (1998). "The skull of dromornithid birds: anatomical evidence for their relationship to Anseriformes (Dromornithidae, Anseriformes)". Records of the South Australian Museum 31: 51–97. 
• Wroe, S.; Field, J.; Fullagar, R. (2002). "Lost giants". Nature Australia 27 (5): 54–61. 
• Prideaux, Gavin J; Roberts, Richard G.; Megirian, Dirk; Westaway, Kira E.; Hellstrom, John C.; Olley, John M. (2007). "Mammalian responses to Pleistocene climate change in southeastern Australia" (PDF). Geology 35 (1): 33–36. doi:10.1130/G23070A.1. http://geology.geoscienceworld.org/cgi/reprint/35/1/33.pdf. 

External links

• Cuddie Springs
• Interview with Dr John Long, curator at the Museum of Victoria
• Naracoorte caves in South Australia
• Lost Kingdoms