Diprotodon

, meaning "two forward teeth", is the largest known marsupial ever to have lived. Along with many other members of a group of unusual species collectively called the "Australian megafauna", it existed from approximately 1.6 million years ago until extinction some 46,000 years ago.

Diprotodon species fossils have been found in sites across mainland Australia, including complete skulls and skeletons, as well as hair and foot impressions. Female skeletons have been found with babies located where the mother's pouch would have been. The largest specimens were hippopotamus-sized: about 3 metres (9.8 ft) from nose to tail, standing 2 metres (6.6 ft) tall at the shoulder and weighing about 2,790 kilograms (6,150 lb). Aboriginal rock art images in Quinkan traditional country (Queensland, Australia) have been claimed to depict diprotodonts. They inhabited open forest, woodlands, and grasslands, possibly staying close to water, and eating leaves, shrubs, and some grasses.

The closest surviving relatives of Diprotodon are the wombats and the koala. It is suggested that diprotodonts may have been an inspiration for the legends of the bunyip, as some Aboriginal tribes identify Diprotodon bones as those of "bunyips". Despite their extinction, there are many unconfirmed sightings of non-bunyip-type diprotodons alive today, just like sightings of thylacines of today.

Discovery
The first recorded Diprotodon remains were discovered in a cave near Wellington in New South Wales in the early 1830s by Major Thomas Mitchell who sent them to England for study by Sir Richard Owen. In the 1840s Ludwig Leichhardt discovered many Diprotodon bones eroding from the banks of creeks in the Darling Downs of Queensland and when reporting the find to Owen commented that the remains were so well preserved he expected to find living examples in the then-unexplored central regions of Australia.

The majority of fossil finds are of demographic groups indicative of diprotodonts dying in drought conditions. For example, hundreds of individuals were found in Lake Callabonna with well-preserved lower bodies but crushed and distorted heads.[7] It is theorised several family groups sank in mud while crossing the drying lake bed. Other finds consist of age groupings of young or old animals which are first to die during a drought.

In 2012, a significant group of about 40 was found at Eulo, South-West Queensland.

Description
Diprotodon superficially resembled a rhinoceros without a horn. Its feet turned inwards like a wombat’s, giving it a pigeon-toed appearance. It had strong claws on the front feet and its pouch opening faced backwards. Footprints of its feet have been found showing a covering of hair which indicates it had a coat similar to a modern wombat.

Until recently it was unknown how many species of Diprotodon had existed. Eight species are described although many researchers believed these actually represented only three at most while some estimated there could be around twenty in total.

Paleobiology
Recent research compared the variation between all of the described Diprotodon species with the variation in one of Australia’s largest living marsupials, the eastern grey kangaroo, and found the range was comparable, with a near continent-wide distribution. This left only two possible Diprotodon species differing only in size with the smaller being around half the size of the larger. According to Gause’s "competitive exclusion principle" no two species with identical ecological requirements can coexist in a stable environment. However, both the small and large diprotodonts coexisted throughout the Pleistocene and the size difference is similar to other sexually dimorphic living marsupials. Further evidence is the battle damage common in competing males found on the larger specimens but absent from the smaller. Dental morphology also supports sexual dimorphism, with highly sexually dimorphic marsupials, such as the grey kangaroo, having different tooth sizes between males and females, but both sexes having the same dental morphology. An identical dental morphology occurs in the large and small Diprotodon. The taxonomic implication is that Owen’s original Diprotodon optatum is the only valid species.

A single sexually dimorphic species allows behavioural interpretations. All sexually dimorphic species of over 5 kilograms (11 lb) exhibit a polygynous breeding strategy. A modern example of this is the gender segregation of elephants where females and the young form family groups while lone males fight for the right to mate with all the females of the group. This behaviour is consistent with fossil finds where adult/juvenile fossil assemblages usually contain only female adult remains.

Extinction
Most modern researchers including Richard Roberts and Tim Flannery argue that diprotodonts, along with a wide range of other Australian megafauna, became extinct shortly after humans arrived in Australia about 50,000 years ago.

Some older researchers including Richard Wright argue on the contrary that diprotodont remains from several sites, such as Tambar Springs and Trinkey and Lime Springs suggest that Diprotodon survived much longer, into the Holocene. Other more recent researchers, including Lesley Head and Judith Field, favour an extinction date of 28,000 - 30,000 years ago, which would mean that humans coexisted with Diprotodon for some 20,000 years. However, opponents of "late extinction" theories have interpreted such late dates based on indirect dating methods as artifacts resulting from redeposition of skeletal material into more recent strata, and recent direct dating results obtained with new technologies have tended to confirm this interpretation.

Three theories have been advanced to explain the mass extinction, Climate change, Human hunting, and Human land management, or even all of the above.

Although Diprotodons are extinct, there are many reported sightings of Diprotodons being still alive today, usually in the outback or in villages.

Lost Tapes
In 2009, footage shows a family of of tourists are on a vacation to Australia, where they are going to live there for few months before heading back to their home in California. The next day after their arrival in Australia, however, they saw some creature that looked nothing like they've seen before and, as the creature saw the tourist family, it charged aggressively towards them. The family escapes for now and. Back at their hotel, the tourist family's boy named Ryan realized he left his Mickey mouse doll behind during the unknown creature attack. He ran out of the hotel to find his doll, only having his parents worried about him. He went back into the scrubland area where the creature charged. He have founded his Mickey mouse doll in the bush undamaged, but he heard a loud bellow and saw where the sound came from. He saw the same creature that attacked his family and it charged at him this time, with Ryan screaming in horror. He ran as fast as his legs could carry, outpacing the large lumbering creature. He made it back to his family, but the police officer named Roger Forland nearby thought there was a serial killer attacking Ryan. Unfortunately for the police officer, the same large creature charged and galloped over the police officer, shatering his bones and organs, thus killing the police officer. The family realized that the creature is real and before they could run into the hotel, the large lumbering beast blocked the doorway, so the family ran into the street as fast as possible. The police enforcements came in time and attempted to shoot the creature, but the creature escapes with little injury. As the creature runs back into the scrubland, the tourist family are shocked with terror.

Killed in Lost Tapes

 * The police officer Roger Forland

Trivia

 * The Diprotodon in this episode is computer generated. Animatronics were used for close up.


 * It is possible that the Diprotodon was only attacking the tourist family because it's protecting its territory.


 * It's also possible that the Diprotodon had attacked the family because it's a mother and had young nearby, just being a protective mother.