Diprotodon, named from the Ancient Greek words dí- (two), prôtos (first), and odoús (tooth), is an extinct group of diprotodontid marsupials from the Pleistocene era in Australia. This group contains one species, D. optatum. The oldest remains are dated to between 1.77 million and 780,000 years ago, but most fossils are from after 110,000 years ago. The first remains were found in 1830 in Wellington Caves, New South Wales. At the time, scientists thought the bones belonged to rhinos, elephants, hippos, or dugongs.
Diprotodon was officially described by English naturalist Richard Owen in 1838. It was the first Australian fossil mammal to be named. This discovery made Owen a leading expert on marsupials and Australian megafauna, which were mysterious to European scientists.
Diprotodon was the largest marsupial ever known. It was much bigger than its living relatives, such as wombats and koalas. It belonged to the extinct family Diprotodontidae, which included other large, four-legged plant-eaters. It stood about 1.8 meters (5 feet 11 inches) tall at the shoulders, measured over 4 meters (13 feet) from head to tail, and likely weighed several tonnes, possibly up to 3,500 kilograms (7,700 pounds). Female Diprotodon were smaller than males. They walked on strong, elephant-like legs and lived across most of Australia. Their fingers and toes were weak, and most of their weight was supported by their wrists and ankles. Their hind legs angled inward at 130 degrees. Their jaws could produce a strong bite force: 2,300 newtons (520 pounds-force) at the front incisors and over 11,000 newtons (2,500 pounds-force) at the back molars. This allowed them to eat large amounts of plant material, such as twigs, buds, and leaves, using their specialized teeth.
Diprotodon is the only known marsupial and metatherian to have made seasonal migrations. Large groups, usually of females, may have traveled through many habitats to find food and water, moving at about 6 kilometers (3.7 miles) per hour. They may have lived in social groups where males competed for mates or defended against predators like Thylacoleo carnifex, the largest known marsupial carnivore. As a marsupial, the mother likely carried her young in a pouch on her belly. The pouch may have faced backward, like in wombats, to which Diprotodon is related.
Diprotodon went extinct about 40,000 years ago during the Late Pleistocene megafauna extinctions, along with all other Australian mammals weighing over 100 kilograms (220 pounds). The extinction may have been caused by severe droughts and hunting by early Aboriginal Australians, who lived alongside Diprotodon for thousands of years before its extinction. There is little direct evidence of interactions between Aboriginal Australians and Diprotodon. Some researchers have suggested that Diprotodon may have inspired certain Aboriginal myths, such as the bunyip, or appeared in rock art, but these ideas are not confirmed.
Research history
In 1830, farmer George Ranken found a group of different fossils while exploring Wellington Caves in New South Wales, Australia. This was the first major place where bones of extinct large Australian animals were discovered. Later, Ranken returned with explorer Major Thomas Mitchell to dig up more bones, including those of Diprotodon.
At the time, people thought the large fossils were from rhinos, elephants, hippos, or dugongs. The fossils were not officially described until 1837, when Mitchell sent them to his former colleague, English naturalist Richard Owen, while Owen was in England. In 1838, Owen studied a jawbone with a tooth and compared it to those of wombats and hippos. He wrote to Mitchell, naming the tooth as part of a new group called Diprotodon. Mitchell published this in his journal. Owen officially described Diprotodon in 1838, but did not name a specific species. In a different part of his work, he listed Diprotodon optatum as the type species.
The name Diprotodon means "two protruding front teeth" in Ancient Greek. Optatum is Latin for "desire" or "wish." It was the first Australian fossil mammal to be officially described. In 1844, Owen changed the name D. optatum to D. australis. Owen only used optatum once, and the use of australis has changed over time, but optatum is now the standard name.
In 1843, Mitchell sent more Diprotodon fossils from the Darling Downs to Owen. Owen thought the fossils were related to elephants, mastodons, or deinotherium. He pointed to the incisors, which he believed were tusks, the shape of the thigh bone similar to elephants and rhinos, and the ridges on the molars, like those of elephants. Later that year, Owen said Diprotodon was the same as Deinotherium, calling it Dinotherium Australe. He changed his mind in 1844 after German naturalist Ludwig Leichhardt showed that the incisors belonged to a marsupial. Owen still called the molars Mastodon australis and thought Diprotodon was likely related to elephants.
In 1847, a nearly complete skull and skeleton of Diprotodon was found in the Darling Downs. The large skeleton attracted many people when it was displayed in Sydney. Leichhardt believed the animal lived in water and thought it might still be alive in an undiscovered area. However, as Europeans explored more of Australia, he became certain the animal was extinct. Owen later became the leading expert on Australian fossils, focusing on marsupials.
Large groups of mostly complete Diprotodon fossils have been found in dry lakes and riverbeds. The largest group was found in Lake Callabonna, South Australia. A worker from an Aboriginal community first noticed the fossils on a sheep property. The owners, the Ragless brothers, told the South Australian Museum, which hired Australian geologist Henry Hurst to dig at the site. Hurst found up to 360 Diprotodon fossils over a few acres. Digging started again in the 1970s, and more fossils were found. American paleontologist Richard H. Tedford suggested that groups of these animals got stuck in mud while crossing water during dry seasons.
In addition to D. optatum, other species were named in the 19th century based on small differences in body structure. Adult Diprotodon fossils show two different size ranges. In 1975, Australian paleontologists J. A. Mahoney and William David Lindsay Ride did not think the size differences were due to differences between males and females, because modern wombats and koalas—its closest living relatives—have similar skeletons. They assumed the same was true for extinct relatives, including Diprotodon.
In 2008, Australian paleontologist Gilbert Price decided to recognize only one species, D. optatum, because there were no differences in their teeth. He believed *D
Classification
Diprotodon is a type of marsupial in the order Diprotodontia, suborder Vombatiformes (which includes wombats and koalas), and infraorder Vombatomorphia (which includes wombats and related animals). Scientists are still unsure how different groups of vombatiforms are related to each other because the best-known members, both living and extinct, are highly specialized and very different from their last common ancestor.
In 1872, American scientist Theodore Gill created the superfamily Diprotodontoidea and the family Diprotodontidae to classify Diprotodon. Later, new species were added to these groups. By the 1960s, scientists found fossils dating back to before the Pliocene, which helped clarify how these groups are related. In 1967, American paleontologist Ruben A. Stirton divided Diprotodontoidea into one family, Diprotodontidae, with four subfamilies: Diprotodontinae (which includes Diprotodon), Nototheriinae, Zygomaturinae, and Palorchestinae. In 1977, Australian paleontologist Michael Archer combined Nototheriinae with Diprotodontinae. In 1978, Archer and Australian paleontologist Alan Bartholomai raised Palorchestinae to family level as Palorchestidae, leaving Diprotodontoidea with two families: Diprotodontidae and Palorchestidae. Diprotodontidae now includes two subfamilies: Diprotodontinae and Zygomaturinae.
According to Australian paleontologists Karen H. Black and Brian Mackness (1999), the Diprotodontoidea family tree includes Phascolarctidae (koalas). Diprotodontidae is the most diverse family in Vombatomorphia. It adapted better to dry, open landscapes over millions of years than other groups in the infraorder. Diprotodon fossils have been found in every Australian state, making it the most widespread Australian megafauna in the fossil record. The oldest known vombatomorph (and vombatiform) is Mukupirna, discovered in 2020 from Oligocene deposits in South Australia dating to 26–25 million years ago. Scientists believe the group evolved even earlier. Mukupirna was already more closely related to wombats than other vombatiforms and weighed about 150 kg (330 lb), while the last common ancestor of vombatiforms was likely a small creature weighing 1–5.5 kg (2.2–12.1 lb).
Both diprotodontines and zygomaturines were diverse during the Late Oligocene to Early Miocene, about 23 million years ago. However, classifications of diprotodontoids from this time are debated. During the Miocene, diprotodontines were rare, with only one known genus, Pyramios. By the Late Miocene, diprotodontians became the most common marsupial order in fossil sites, a trend that continues today. Diprotodontids and kangaroos were the most numerous. Diprotodontidae also showed a trend toward gigantism, likely due to the need to eat more low-quality plant food in drier climates. Gigantism evolved independently six times among vombatiform lineages. Diprotodontine diversity increased in the Pliocene, with Diprotodontidae reaching its peak with seven genera, coinciding with the spread of open forests. In 1977, Archer stated that Diprotodon directly evolved from the smaller Euryzygoma, found in Pliocene deposits in eastern Australia dating to before 2.5 million years ago.
In general, the ages of Australian fossil sites are poorly understood. While the geochronology of Diprotodon is among the best for Australian megafauna, it remains incomplete, and most remains are undated. Price and Australian paleontologist Katarzyna Piper reported the earliest indirectly dated Diprotodon fossils from the Nelson Bay Formation in New South Wales, dating to 1.77 million to 780,000 years ago during the Early Pleistocene. These fossils are 8–17% smaller than Late Pleistocene Diprotodon fossils but otherwise identical. The oldest directly dated Diprotodon fossils come from the Boney Bite site in Floraville, New South Wales, deposited about 340,000 years ago during the Middle Pleistocene, based on U-series and luminescence dating of quartz and orthoclase. Floraville is the only known Middle Pleistocene site in tropical northern Australia. Most other dated Diprotodon material comes from Marine Isotope Stage 5 (MIS5) or younger, meaning after 110,000 years ago during the Late Pleistocene.
Description
Diprotodon had a long, narrow skull. Like other marsupials, the top of its skull was flat or sunken over the small braincase and the hollow spaces in the frontal bone. Like many large vombatiformes, the frontal sinuses (hollow spaces) were large. In one specimen from Bacchus Marsh, these sinuses took up 2,675 cc (163.2 cu in)—about 25% of the skull’s volume—while the brain occupied 477 cc (29.1 cu in)—only 4% of the skull’s volume. Marsupials usually have smaller brain-to-body size ratios than placental mammals. However, this difference becomes more noticeable in larger animals, possibly because the brain uses a lot of energy, and marsupials have lower maternal metabolic rates due to shorter gestation periods. The large sinuses increased the surface area for the temporalis muscle to attach, which helped with biting and chewing, compensating for the smaller braincase. These sinuses may also have helped spread stress from biting across the skull more efficiently.
The occipital bone, at the back of the skull, sloped forward at 45 degrees, unlike most modern marsupials, where it is vertical. The base of the occipital bone was thick. The occipital condyles (bones connecting the skull to the spine) were semi-circular, with the bottom narrower than the top. The inner edge of the foramen magnum (the hole where the spinal cord passes through) was thin and clearly defined. The top edge of the foramen magnum was flattened, not arched. The foramen expanded backward and upward toward the inlet, resembling a short neural canal (a tube in the spine) more than a foramen magnum.
A sagittal crest (a bony ridge) ran across the skull’s midline from the top of the occipital bone to the area between the eyes. The eye socket was small and vertically oval. The nasal bones curved upward near their ends and then downward, creating an S-shaped curve. Like many marsupials, most of the nasal septum (the wall dividing the nose) was made of bone, not cartilage. The nose would have been very flexible. The skull’s height from the top of the occipital bone to the end of the nasal bones was nearly uniform, with the nasal bones being the tallest point. The zygomatic arch (cheekbone) was strong and deep, like in kangaroos, and extended from the top of the occipital bone to the area between the eyes.
Like kangaroos and wombats, there was a gap between the palate (roof of the mouth) and the upper jaw behind the last molar, filled by the medial pterygoid plate. This plate attached to the medial pterygoid muscle, which helped close the jaw. Like many grazers, the masseter muscle (another jaw-closing muscle) was the dominant jaw muscle. A large temporal muscle compared to the lateral pterygoid muscle suggests limited side-to-side jaw movement, meaning Diprotodon was better at crushing food than grinding it. The masseter’s attachment point was forward, near the eye sockets, which may have helped control the incisors. Diprotodon’s chewing style was more like kangaroos than wombats: a strong vertical crunch followed by a side-to-side grinding motion.
Like other marsupials, the mandible’s ramus (the part connecting to the skull) angled inward. The condyloid process (the part connecting the jaw to the skull) was similar to that of a koala. The ramus was straight and nearly vertical, thickening near the mandible’s body (where the teeth are). The mandible’s body became deeper from the last molar to the first. The strong mandibular symphysis (the fused part of the lower jaw) started at the front of the third molar, preventing each half of the jaw from moving independently, unlike in kangaroos.
Diprotodon’s dental formula was 3.0.1.4 1.0.1.4. Each jaw had three upper incisors and one lower incisor, one premolar and four molars in both jaws, but no canines. A long gap (diastema) separated the incisors from the molars.
The incisors were chisel-shaped (scalpriform). Like those of wombats and rodents, the first incisors in both jaws grew continuously throughout the animal’s life, but the other two upper incisors did not. This combination is not seen in any living marsupial. The upper incisors had a circular cross-section. In one old male specimen, the first upper incisor measured 280 mm (11 in), with 220 mm (8.5 in) inside the tooth socket; the second was 100 mm (4 in), with 25 mm (1 in) in the socket; and the third’s exposed part was 66 mm (2.6 in). The first incisor curved outward, while the others curved inward. The lower incisor had a slight upward curve, was straight, and had an oval cross-section. In the same specimen, the lower incisor measured 250 mm (10 in), with two-thirds inside the socket.
The premolars and molars were bilophodont (each had two distinct ridges). The premolar was triangular and about half the size of the molars. Like kangaroos, the ridges on the molars were coated in cementum. Unlike kangaroos, there was no connecting ridge between the ridges. The ridges’ peaks had thick enamel that thinned toward the base, which could wear away over time, exposing dentine and osteodentine beneath. Like other marsupials, only the first molar of Diprotodon and wombats was replaced. The premolars of D. optatum varied greatly in shape even within the same individual.
Diprotodon had seven cervical (neck) vertebrae. The atlas (first cervical, C1) had deep cavities for the occipital condyles. The atlas’s diaphophyses (upward projections) were short and thick, like those of wombats and koalas. The articular surface of the axis (C2), where it connects to another vertebra, was slightly concave on the front and flat on the back. Like kangaroos, the axis had a low, triangular projection (hypophysis) on its underside and a long odontoid (a projection fitting into
Paleobiology
During the Pleistocene era, large herbivores in Australia, such as the Diprotodon, likely had a significant impact on the environment by reducing the growth of forests and woody plants. Studies of carbon isotopes suggest that Diprotodon ate a wide variety of plants, including both C3 plants (such as well-watered trees, shrubs, and grasses) and C4 plants (such as dry grasses), similar to kangaroos. This finding is supported by calcium isotope analysis, which also shows Diprotodon had a mixed diet. Analysis of Diprotodon remains from the Cuddie Springs site, dated to around 45,000 and 350,000 to 570,000 years ago, indicates that its diet became slightly more varied as Australia’s climate became drier, though changes were minor. In contrast, kangaroos and wombats experienced major shifts in their diets, favoring C3 or C4 plants, respectively. Fossilized remains from a 53,000-year-old Diprotodon at Lake Callabonna show its last meal included young leaves, stalks, and twigs.
Diprotodon had simple, bilophodont-shaped molars, similar to those of kangaroos. Kangaroos use these teeth to grind both soft, low-fiber plants (as browsers) and grass (as grazers). Grazing kangaroos have specialized molars to withstand the roughness of grass, but Diprotodon lacked such adaptations, suggesting it had a mixed diet, similar to a browsing wallaby. It may have chewed by first crushing food vertically and then grinding it horizontally, unlike wombats, which only grind horizontally. Like many large hoofed mammals, Diprotodon’s jaws were better suited for crushing vegetation in bulk rather than grinding. It is unclear if Diprotodon excreted cube-shaped droppings, as modern wombats do.
In 2016, scientists Alana Sharpe and Thomas Rich used a method called finite element analysis to estimate Diprotodon’s maximum bite force. They calculated 2,374 N (534 lb) at the incisors and 4,118 to 11,134 N (926 to 2,503 lb) across the molars. For comparison, American alligators can produce forces up to 9,500 N (2,100 lb). Though these numbers may be overestimates, they suggest Diprotodon had very strong jaws, allowing it to eat tough, fibrous grasses.
In 2017, researchers analyzed strontium isotope ratios in a Diprotodon tooth from the Darling Downs. By comparing these ratios to those from different regions, they determined that Diprotodon made seasonal migrations, likely to find food or water. This individual followed the Condamine River, making a 200 km (120 mi) round trip northwest-southeast each year. This migration pattern is similar to those of modern large mammals in East Africa.
Diprotodon is the only known metatherian (a group of mammals that includes marsupials) to migrate seasonally between two locations. While some modern marsupials, like red kangaroos, migrate when needed, this is not a regular, seasonal behavior. Because Diprotodon did migrate, it is likely other Pleistocene Australian megafauna also had seasonal movements.
Diprotodon likely lived in large herds. Fossil evidence, mostly found in southeastern Australia, suggests these herds were mostly or entirely female and sometimes included juveniles. This pattern is common in polygynous species, where a group of females lives together, breeding only with a dominant male. The Diprotodon’s skull was adapted to handle high stress, suggesting it may have used its teeth or jaws for activities beyond eating, such as fighting for mates or defending against predators. Like modern kangaroos, male Diprotodon herds may have been less able to survive droughts due to their larger size and higher nutritional needs.
Scientists can study the movement of extinct animals by examining fossil trackways, though these are rare in Australia. Trackways of humans, kangaroos, wombats, Diprotodon, and the diprotodontid Euowenia have been identified. At Lake Callabonna and the Victorian Volcanic Plain, Diprotodon trackways show that the animal had a semi-circular front paw print and a kidney-shaped hind paw print. Most of its weight was supported by the wrist and ankle bones, allowing it to move with a more upright posture, similar to elephants, rather than the sprawling stance of wombats.
At Lake Callabonna, a Diprotodon left track impressions with an average stride length of 1,500 mm (4 ft 11 in), trackway width of 430 mm (1 ft 5 in), and track dimensions of 295 mm × 202 mm (11.6 in × 8.0 in). Its shoulder-to-hip length was estimated at 1,125 mm (3 ft 8 in), and it likely moved at around 6.3 km/h (3.9 mph). Another trackway at the volcanic plain had a shorter stride length of 1,310 mm (4 ft 4 in), trackway width of 660 mm (2 ft 2 in), and a hind paw length of 450 mm (1 ft 6 in). This animal may have been a female carrying a large joey, which affected its gait. The trackway stretched 62.8 m (206 ft) in a southerly direction, with the animal hesitating near a sandbar and leaving overlapping prints. Another trackway 50 m (160 ft) away may have been made by the same individual.
Marsupials, such as Diprotodon, have a metabolic rate about 3
Palaeoecology
Diprotodon lived across the entire Australian continent during the Late Pleistocene, especially after about 110,000 years ago. The start of the Quaternary ice ages caused glaciers at the poles to advance and retreat, leading to major climate changes in other areas. In Australia, warmer and wetter periods supported forests and woodlands, while colder and drier periods encouraged grasslands and deserts. Over time, Australia became drier as the influence of Asian monsoons weakened. By 500,000 years ago, the interior of the continent was mostly dry and sandy. Large lakes in north-western Australia, which were common during warm periods, dried up, and rainforests in eastern Australia gradually disappeared. Drier conditions became more common after 100,000 years ago, especially after 60,000 years ago, when El Niño–Southern Oscillations became more frequent.
Diprotodon lived in many different habitats, much like modern African elephants in Africa south of the Sahara. It was part of a group of large animals that lived in Australia during the Pleistocene. These included the thylacine, modern kangaroos, giant short-faced kangaroos, various koalas and wombats, the tapir-like Palorchestes, the giant turtle Meiolania, and the giant bird Genyornis. Diprotodon lived alongside Zygomaturus trilobus, which stayed in forests, while Diprotodon moved through expanding grasslands and woodlands. Other diprotodontids, such as Hulitherium, Z. nimborensia, and Maokopia, lived only in the forests of New Guinea.
Because of its large size, Diprotodon was a difficult target for predators. It lived with the largest known marsupial predator, Thylacoleo carnifex. Fossils show that T. carnifex may have attacked Diprotodon, but it is unclear if the 100–130 kg predator could kill an animal weighing up to 2,000 kg. Modern jaguars, which are about half the size of T. carnifex, can kill a 500 kg bull, so it is possible T. carnifex could have killed smaller Diprotodon. Like modern kangaroos, young Diprotodon may have been more vulnerable to predators. Fossils of juvenile Diprotodon and T. carnifex have been found in the same caves.
The largest predators in Australia were reptiles, including the saltwater crocodile, the now-extinct Paludirex and Quinkana crocodiles, and the giant lizard megalania (Varanus priscus). Megalania was the largest carnivore in Pleistocene Australia, reaching lengths of 7 meters (23 feet).
As part of the Quaternary extinction event, Diprotodon and all other Australian land animals heavier than 100 kg (220 lb) became extinct. The timing and exact cause of this extinction are unclear because fossil sites in Australia have poor dating records. Historically, scientists have blamed climate change or overhunting by early Aboriginal people for the extinction of Australia’s megafauna. In 2001, Australian paleontologist Richard Roberts and colleagues dated 28 major fossil sites across the continent, providing precise dates for the extinction. Most megafauna disappeared from the fossil record by 80,000 years ago, but Diprotodon, the giant wombat Phascolonus, Thylacoleo, and short-faced kangaroos were found in Ned’s Gully, Queensland, and Kudjal Yolgah Cave, Western Australia, dated to 47,000 and 46,000 years ago. This suggests that all Australian Pleistocene megafauna likely died out between about 50,000 and 41,000 years ago. Studies show that megafauna populations in western and eastern Australia died out at the same time. As of 2021, no evidence has been found to show megafauna survived past about 40,000 years ago. The latest known Diprotodon fossils are from South Walker Creek mine, dated to about 40,100 ± 1,700 years ago.
At the time Roberts and colleagues published their findings, the earliest evidence of human activity in Australia was dated to about 56,000 years ago, close to their calculated extinction date. They suggested that human hunting may have caused the last megafauna to disappear within about 10,000 years of coexisting with humans. Human hunting was previously linked to the extinction of megafauna in North America and New Zealand. At the time, scientists believed human activity was the main cause of Australia’s megafaunal extinction, especially since these animals had survived extreme droughts during ice ages. There was no clear evidence of unusually harsh climate conditions during the extinction period. Because marsupials reproduce slowly, even small amounts of hunting could have severely harmed their populations.
In 2005, American geologist Gifford Miller noted that fires became more frequent around 45,000 years ago. He linked this to Aboriginal people using controlled burns to clear forests and grasslands for farming. This change in vegetation may have harmed megafauna by replacing their habitats with fire-resistant scrub. Later studies struggled to confirm a direct link between controlled burns and major ecological changes. Increased fire frequency could also have resulted from the extinction of megafauna, as their absence may have led to faster fuel buildup from plants.
In 2017, a rock shelter called Madjedbebe on Australia’s northern coast was dated to about 65,000 years ago. If correct, this would mean humans and megafauna coexisted for over 20,000 years. However, some scientists question this dating. In the 2010s, several ecological studies suggested that severe droughts coincided with the final extinctions of megafauna. Scientists now believe the extinction may have been caused by a combination of climate change, human hunting, and human-driven changes to the landscape.
Cultural significance
Despite the belief that the first Aboriginal Australians may have played a role in the extinction of Diprotodon and other large mammals in Australia, there is little evidence that humans used these animals during the 20,000 years they lived together. No fossils of these large mammals show signs of being cut or cooked by humans.
In 1984, Gail Paton found an upper-right Diprotodon tooth in Spring Creek, Victoria. This tooth had 28 visible marks that looked like cuts. Ron Vanderwald and Richard Fullager studied the tooth, which was split in half but later glued together before they could examine it fully. Each half was 40 cm long. The marks were straight and measured between 0.91–4.1 mm in length, 0.14–0.8 mm in width, and 0.02–0.24 mm in depth. Researchers said the marks were not from animals like Thylacoleo or mice. They thought humans used flint to make the marks, possibly as a counting tool or a drawing. Later, in 2020, Michelle Langley, a scientist, studied the tooth again and concluded the marks were likely made by a tiger quoll, a type of animal.
In 2016, Giles Hamm and other scientists found part of a Diprotodon’s arm bone in a rock shelter in Warratyi. Because the bone showed no signs of damage from predators and the rock shelter was on a steep cliff, they believed humans brought the Diprotodon to the site.
When large fossils were first discovered in Australia, scientists were unsure what animals they belonged to because no experts were on the continent at the time. Some local people thought the fossils might be from rhinos or elephants. European settlers, like Reverend John Dunmore Lang, claimed the fossils proved a story from the Bible about a great flood. Aboriginal Australians also tried to explain the fossils using their own beliefs, connecting Diprotodon to the bunyip, a mythical creature said to live in lakes. Some scientists thought the bunyip might be a memory of Diprotodon, but it was unclear if these animals were extinct because Australia had not been fully explored. In 1846, a skull thought to be from a bunyip was displayed in a museum, but later it was identified as a foal’s skull, showing that early scientists made mistakes.
In 1892, a Canadian geologist named Henry Yorke Lyell Brown reported that Aboriginal people in Lake Eyre identified Diprotodon fossils as belonging to the Rainbow Serpent, a mythical creature they believed was a giant fish. Later, a British geologist named John Walter Gregory thought the Rainbow Serpent might be a mix of Diprotodon and a crocodile. These ideas were not testable and relied on stories passed down over thousands of years. If Aboriginal myths about Diprotodon are based on these animals, it is unclear whether the stories described the creatures when they were alive or the fossils found long after their extinction.
Aboriginal Australians painted many animals in caves, but the subjects of these paintings are often hard to identify. In 1907, Herbert Basedow, an Australian anthropologist, found footprints in caves that he thought were from Diprotodon. In 1988, Percy Trezise, a historian, claimed a painting showed Diprotodon. However, these claims are not accurate because the paintings have features that do not match what scientists know about Diprotodon. Unlike the realistic art of ancient Europeans, Aboriginal paintings often show mythical creatures from the Dreaming, making them harder for outsiders to understand.