Genyornis Temporal range: Late Pleistocene | |
---|---|
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Aves |
Superorder: | Galloanserae |
Family: | † Dromornithidae |
Genus: | † Genyornis Stirling & Zietz, 1896 |
Species: | †G. newtoni |
Binomial name | |
†Genyornis newtoni Stirling & Zietz, 1896 [1] | |
Genyornis newtoni, also known as the Newton's mihirung, Newton's thunder bird or mihirung paringmal (meaning "giant bird" in Tjapwuring), is an extinct species of large, flightless bird that lived in Australia during the Pleistocene Epoch until around 50,000 years ago. Over two metres in height, they were likely herbivorous. [2] Many other species of Australian megafauna became extinct in Australia around that time, coinciding with the arrival of humans. It is the last known member of the extinct flightless bird family Dromornithidae which had been part of the fauna of the Australian continent for over 30 million years. They are not closely related to ratites such as emus, and their closest living relatives are thought to be fowl.
The species was first described in 1896 by Edward Charles Stirling and A. H. C. Zeitz, the authors giving the epithet newtoni for the Cambridge professor Alfred Newton. The name of the genus is derived from the ancient Greek γένυς (génus) 'jaw; chin' and ὄρνις (órnis) 'bird', because of the relatively large size of the lower mandible. [1] The specimen is a left femur. [1] [3] It was found at Lake Callabonna in South Australia. The excavation was undertaken and described by Zietz. A description of the excavation was reported in Nature [4] [5] which had also unearthed material recognised as marsupials.
Numerous fragments of avian fossils were noticed in the clay surrounding the removal of diprotodont fossils, then largely complete specimens including crucial evidence of the crania emerged from the site. The paper reviewed previously described fossil remains of "struthious [ ostrich-like] birds in Australia", which had either been assigned to the ancient emus of Dromaius or the only described species of Dromornis , D. australis Owen. [1]
A letter from George Hurst concerning the discovery of a partial skeleton of the species alerted Stirling to its existence in 1893. [3]
The placement of this dromornithid species may be summarised as:
Dromornithidae (8 species in 4 genera) [2]
Genyornis newtoni was a medium-sized dromornithid with a robust body, measuring up to 2.15 metres (7.1 ft) tall and weighing around 250–350 kilograms (550–770 lb), though body mass estimation may vary based on different methods. [6] While larger than Ilbandornis , it did not attain the height and weight of Dromornis stirtoni or Dromornis planei . [6] The fossils of the species have been found remaining in articulation, and no other dromornithid species has been discovered in this state. The remains of eggs have also been attributed to this species. Gastroliths belonging to these animals have been found alongside their remains, a feature that has revealed the sometimes shallow site of fossils. [3]
Prior to 2024, reconstructions of the skull of Genyornis were primarily based on those of its closest relatives, due to the heavily damaged nature of the holotype. However, a 2024 study on the skull morphology of Genyornis, incorporating a recently-discovered well-preserved skull, found the physical appearance of the head of Genyornis to be much more different than previously believed. Namely, the bill was found to be much more goose-like, with a raised triangular casque. This goose-like bill differed from even other mihirungs, and may have been a specialization for feeding on aquatic vegetation. Other potential adaptations to an aquatic feeding style may have allowed for protection of the ears and throat when submerging their heads in water. [7] [8]
This mihirung has been found at sites in South Australia, New South Wales, Queensland and Western Australia, dating to the Pleistocene Epoch. Genyornis newtoni is the only species of dromornithid known to have existed during the Pleistocene. [3]
Two main theories propose a cause for megafauna extinction - human impact and changing climate. A study has been performed in which more than 700 Genyornis eggshell fragments were dated. [9] Through this, it was determined that Genyornis declined and became extinct over a short period—too short for it to be plausibly explained by climate variability. The authors considered this to be a very good indication that the entire mass extinction event in Australia was due to human activity, rather than climate change.
A 2015 study collected egg shell fragments of Genyornis from around 200 sites that show burn marks. [10] Analysis of amino acids in the egg shells showed a thermal gradient consistent with the egg being placed on an ember fire. The egg shells were dated to between 53.9 and 43.4 thousand years BP, suggesting that humans were collecting and cooking Genyornis eggs in the thousands of years before their extinction. A later study suggested that the eggs actually belonged to the giant malleefowl, a species of extinct megapode. [11] [12]
A 2022 study examined the protein sequences of these unidentified eggshells and, through phylogenetic analysis, concluded that the lineage that produced these eggs diverged prior to the emergence of megapodes, supporting the previous implication that the eggs in question were produced by Genyornis. [13] The authors noted that the exploitation of Genyornis eggs appears to mirror that of earlier human usage of ostrich eggs throughout the Pleistocene in Northern Africa, the Arabian Peninsula, Southwestern and Northern Asia, and present-day India and China, though they were unable to determine to what extent humans interacted with Genyornis. [14]
A 2021 study found that, if Genyornis eggs were being consumed at similar rates to the eggs of the emu and the Australian brushturkey, then Genyornis would have become extinct at far lower rates of total consumption than these still-extant birds. [15]
In May 2010, archaeologists announced the rediscovery of an Aboriginal rock art painting, possibly 40,000 years old, at the Nawarla Gabarnmung rock art site in the Northern Territory, that they suggested depicts two Genyornis individuals. [16] In 2011, late survival of Genyornis in temperate south west Victoria was suggested, based on Aboriginal traditions. [17] A later study suggested that the painting could not be more than 14,000 years old, long after the bird is thought to have gone extinct, [18] [19] and it could not be morphologically distinguished from depictions of other birds. [20]
In a 2022 study, fossil evidence suggests that the population of Genyornis at Lake Callabonna died around 50,000 years ago, as the lake dried up as the climate changed and became drier. The birds recovered from the site seemed to have been particularly prone to osteomyelitis, as a result of getting stuck in the mud of the drying lake bed as the water receded. Eventually, when the lake dried, the population was left without their main source of water and subsequently died out. [21]
A 2024 study of the skull morphology of Genyornis found apparent adaptations to feeding on aquatic plants, making them closely tied to freshwater habitats. A reliance on these habitats may have made the species uniquely vulnerable to the loss of freshwater lakes during the aridification of Australia during the late Pleistocene, potentially leading to its extinction. [7] [8]
Diprotodon is an extinct genus of marsupial from the Pleistocene of Australia containing one species, D. optatum. The earliest finds date to 1.77 million to 780,000 years ago but most specimens are dated to after 110,000 years ago. Its remains were first unearthed in 1830 in Wellington Caves, New South Wales, and contemporaneous paleontologists guessed they belonged to rhinos, elephants, hippos or dugongs. Diprotodon was formally described by English naturalist Richard Owen in 1838, and was the first named Australian fossil mammal, and led Owen to become the foremost authority of his time on other marsupials and Australian megafauna, which were enigmatic to European science.
In zoology, megafauna are large animals. The precise definition of the term varies widely, though a common threshold is approximately 45 kilograms (99 lb), with other thresholds as low as 10 kilograms (22 lb) or as high as 1,000 kilograms (2,200 lb). Large body size is generally associated with other traits, such as having a slow rate of reproduction and, in large herbivores, reduced or negligible adult mortality from being killed by predators.
Rails are a large, cosmopolitan family of small- to medium-sized terrestrial and/or semi-amphibious birds. The family exhibits considerable diversity in its forms, and includes such ubiquitous species as the crakes, coots, and gallinule; other rail species are extremely rare or endangered. Many are associated with wetland habitats, some being semi-aquatic like waterfowl, but many more are wading birds or shorebirds. The ideal rail habitats are marsh areas, including rice paddies, and flooded fields or open forest. They are especially fond of dense vegetation for nesting. The rail family is found in every terrestrial habitat with the exception of dry desert, polar or freezing regions, and alpine areas. Members of Rallidae occur on every continent except Antarctica. Numerous unique island species are known.
Elephant birds are extinct flightless birds belonging to the order Aepyornithiformes that were native to the island of Madagascar. They are thought to have become extinct around 1000 AD, likely as a result of human activity. Elephant birds comprised three species, one in the genus Mullerornis, and two in Aepyornis.Aepyornis maximus is possibly the largest bird to have ever lived, with their eggs being the largest known for any amniote. Elephant birds are palaeognaths, and their closest living relatives are kiwi, suggesting that ratites did not diversify by vicariance during the breakup of Gondwana but instead convergently evolved flightlessness from ancestors that dispersed more recently by flying.
The term Australian megafauna refers to the megafauna in Australia during the Pleistocene Epoch. Most of these species became extinct during the latter half of the Pleistocene, and the roles of human and climatic factors in their extinction are contested.
Dromornithidae, known as mihirungs and informally as thunder birds or demon ducks, were a clade of large, flightless Australian birds of the Oligocene through Pleistocene epochs. All are now extinct. They were long classified in Struthioniformes, but are now usually classified as galloanseres. Dromornithids were part of the Australian megafauna. One species, Dromornis stirtoni, was 3 m tall. Only a single species, Genyornis newtoni survived into the Late Pleistocene. They are thought to have been herbivorous.
Dromornis is a genus of large to enormous prehistoric birds native to Australia during the Oligocene to Pliocene epochs. The species were flightless, possessing greatly reduced wing structures but with large legs, similar to the modern ostrich or emu. They were likely to have been predominantly, if not exclusively, herbivorous browsers. The male of the largest species, Dromornis stirtoni, is a contender for the tallest and heaviest bird, and possibly exhibited aggressive territorial behaviour. They belong to the family Dromornithidae, extinct flightless birds known as mihirungs.
Ilbandornis was a genus of ostrich-sized dromornithid. It was far more lightly built than other members of the family, indicating a more cursorial lifestyle. The majority of researchers consider Dromornithids to be herbivorous; this is borne out by molecular analysis of the gastroliths and eggshells of both Ilbandornis and the related Genyornis. While Ilbandornis and Genyornis have skulls of similar size to emus, other Dromornithids such as Dromornis have far more robust skulls with large beaks; these were previously considered an adaptation for carnivory, but their blunt edges and lack of hooked tip indicate that the species were herbivorous. It is therefore likely that the differences in skull shape are due to differences in diet.
Barawertornis tedfordi was a dromornithid (mihirung), a large flightless fowl hailing from Late Oligocene to Early Miocene. The only species in the genus Barawertornis, its fossil remains are found in strata of the Riversleigh deposits located at two sites in Northwestern Queensland, Australia.
Lake Callabonna is a dry salt lake with little to no vegetation located in the Far North region of South Australia. The 160-square-kilometre (62 sq mi) lake is situated approximately 120 kilometres (75 mi) southwest of Cameron Corner, the junction of South Australia, Queensland and New South Wales. It is also known as Lake Mulligan.
Sylviornithidae is an extinct family of flightless birds, known from subfossil bones found in Holocene aged deposits on the Melanesian islands of New Caledonia and Fiji. For many years it was considered a monotypic family consisting of the New Calendonia Sylviornis alone, but recent studies show that the Fijian Megavitiornis was part of this clade as well. Long considered to have galliform affinities, a 2016 study suggested that they were outside the Galliformes crown group, while a 2024 study suggested that they were members of the Galliformes crown group as more closely related to Phasianoidea than to Megapodiidae, and were most closely related to the extinct giant gastornithids.
Sthenurus is an extinct genus of kangaroos. With a length around 3 m (10 ft), some species were twice as large as modern extant species. Sthenurus was related to the better-known Procoptodon. The subfamily Sthenurinae is believed to have separated from its sister taxon, the Macropodinae, halfway through the Miocene, and then its population grew during the Pliocene.
Phascolonus is an extinct genus of giant wombat known from the Pliocene and Pleistocene of Australia. There is only a single known species, Phascolonus gigas, the largest wombat ever known to have existed, estimated to weigh as much as 200 kg or 360 kg (790 lb). It was described by Richard Owen in 1859. Phascolomys magnus is a probable junior synonym. P. gigas is distinguished from other wombats by its strap-shaped upper incisors. The cranial roof also is noticeably inwardly depressed. The species was abundant across Australia, with remains having been found in all states except Western Australia. It is suggested to have had a preference for arid and semi-arid inland habitats, with a diet consisting of a high amount of low quality vegetation. Though it likely had wide home-ranges, it probably did not stray far from fresh water sources. Abundant remains have been found in Pleistocene aged deposits from Lake Callabonna in South Australia. Unlike its living relatives, it is unlikely that Phascolonus engaged in burrowing. Phascolonus disappeared during the Late Pleistocene Quaternary extinction event around 50-40,000 years ago, together with many other large Australian animals, following the arrival of humans to the Australian continent. Phylogenetic analysis suggests that is closely related to the other giant wombat genera Ramsayia and Sedophascolomys.
Gastornithiformes are an extinct order of giant flightless fowl with fossils found in North America, Eurasia, possibly Australia. Members of Gastornithidae were long considered to be a part of the order Gruiformes. However, the traditional concept of Gruiformes has since been shown to be polyphyletic.
Zygomaturus is an extinct genus of giant marsupial belonging to the family Diprotodontidae which inhabited Australia from the Late Miocene to Late Pleistocene.
Pangalliformes is the scientific name of a provisional clade of birds within the group Galloanserae. It is defined as all birds more closely related to chickens than to ducks, and includes all modern chickens, turkeys, pheasants, and megapodes, as well as extinct species that do not fall within the crown group Galliformes.
Progura is an extinct genus of megapode that was native to Australia. It was described from Plio-Pleistocene deposits at the Darling Downs and Chinchilla in southeastern Queensland by Charles De Vis.
The Odontoanserae is a proposed clade that includes the family Pelagornithidae and the clade Anserimorphae. The placement of the pseudo-toothed birds in the evolutionary tree of birds has been problematic, with some supporting the placement of them near the orders Procellariformes and Pelecaniformes based on features in the sternum.
Amandus Heinrich Christian Zietz was a zoologist and paleontologist born in Hamburg, Schleswig-Holstein, and best known for his work at the South Australian Museum in Adelaide, after arriving in South Australia in 1883.