Dromornithidae

Els dromornítids (Dromornithidae) va ser una família d'aus no-voladores gegantes prehistòriques que visqueren a Austràlia des del període Oligocè o tal vegada fins abans, però es van extingir (juntament amb la resta de la megafauna australiana) durant el Plistocè. Pertanyien a l'ordre dels anseriformes, sent per tant parents distants dels ànecs i oques actuals. Un animal d'aquesta família, Dromornis stirtoni va ser possiblement la major au que ja va viure.

L'alimentació d'aquestes aus és un misteri. Mentre algunes, com Genyornis, aparentam haver tingut una alimentació essencialmente herbívora, unes altres com el ja esmentat Dromornis stirtoni, poden haver estat voraces carnívores. I hi ha encara unes altres que poden haver estat onívoras o carniceiras.

A Wikimedia Commons hi ha contingut multimèdia relatiu a: Dromornítids

Die Donnervögel (Dromornithidae) waren große, flugunfähige Vögel aus Australien und Tasmanien. Sie sind auch unter dem Namen Riesenemus oder in Australien als Mihirungs bekannt und gehören zu den Gänsevögeln (Anseriformes). Die ältesten Funde sind ca. 20 Millionen Jahre alt.

Dromornis australis und der Stirton-Donnervogel (Dromornis stirtoni) wurden über eine halbe Tonne schwer und 3 Meter hoch. Genyornis newtoni lebte noch im Pleistozän und war den Aborigines bekannt. Knochenfunde in menschlichen Siedlungen zeigen, dass er gejagt wurde. Er starb vor ca. 11.000 Jahren aus.

Ihr Aussterben ist auf die Klimaveränderungen, Buschbrände und möglicherweise die Jagd zurückzuführen.

Systematik

Äußere Systematik

Die systematische Stellung der Donnervögel wurde unterschiedlich ausgelegt wie nachstehende Kladogramme wiedergeben.

nach Murray, 2003

^[1]

† Gastornis

Gänsevögel

Wehrvögel (Anhimidae)

† Donnervögel (Dromornithidae)

Spaltfußgänse (Anseranatidae)

† Presbyornis

Entenvögel (Anatidae)

Vorlage:Klade/Wartung/Style

nach Agnolin, 2007

^[2]

† Gastornithidae (Gastornis u. a.)

Gänsevögel

† Brontornithidae (Brontornis u. a.)

† Donnervögel (Dromornithidae)

Anseres

Entenvögel i. w. S. (Anatoidea)

Spaltfußgänse (Anseranatidae)

Wehrvögel (Anhimidae)

Vorlage:Klade/Wartung/Style

Innere Systematik

Es sind fünf Gattungen mit acht Arten beschrieben:

• Barawertornis
  • Barawertornis tedfordi Rich, 1979
• Bullockornis
  • Bullockornis planei Rich, 1979
• Dromornis
  • Dromornis australis Owen, 1872
  • Dromornis murrayi Worthy, Handley, Archer & Hand, 2016^[3]
  • Dromornis stirtoni Rich, 1979
• Genyornis
  • Genyornis newtoni Stirling & Zietz, 1896
• Ilbandornis
  • Ilbandornis lawsoni Rich, 1979
  • Ilbandornis woodburnei Rich, 1979

Literatur

• Alan Feduccia: The Origin and Evolution of the Birds. 2. Aufl., Yale University Press, New Haven/ London 1999, ISBN 0-300-07861-7.
• Peter F. Murray: Magnificent Mihirungs: The Colossal Flightless Birds of the Australian Dreamtime. Indiana University Press, 2003, ISBN 0-253-34282-1.

Einzelnachweise

1. ↑ Peter F. Murray (2003): S. 169.
2. ↑ Federico L. Agnolin: Brontornis burmeisteri Moreno & Mercerat, un Anseriformes (Aves) gigante del Mioceno Medio de Patagonia, Argentina. Revista del Museo Argentino de Ciencias Naturales Nueva Serie 9, 2007, S. 15–25.
3. ↑ Trevor H. Worthy, Warren D. Handley, Michael Archer and Suzanne J. Hand. 2016. The Extinct Flightless Mihirungs (Aves, Dromornithidae): Cranial Anatomy, A New Species, and Assessment of Oligo-Miocene Lineage Diversity. Journal of Vertebrate Paleontology. DOI: 10.1080/02724634.2015.1031345

Dromornithidae wis a familie o lairge, flichtles foul sib tae geese that steyed in Australia til the end o the Pleistocene, but haes nou wede awa. Hit isna kent gin thay wis hailie carnivores or juist scaffengers.

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.^[1][2][3]

Dromornithids were part of the Australian megafauna. One species, Dromornis stirtoni, was 3 m (9 ft 10 in) tall. Only a single species, Genyornis newtoni survived into the Late Pleistocene.^[4][5]

They are thought to have been herbivorous.^[6]

The scientific name Dromornithidae derives from the Greek words δρομαίος, dromaios ("swift-running") and ὀρνις, ornis ("bird").^[7]

Classification

The family was named by Max Fürbringer in 1888, citing W. B. Clarke and Gerard Krefft, Owen's separation from "Dromaeus" and Dinornis, and a note by von Haast allying Dromornis with Dromaeus.^[8][9] What the nearest relatives of this group are is a controversial issue. For many years it was thought that dromornithids were related to ratites, such as emus, cassowaries, rheas and ostriches. It is now believed that the similarities between these groups are the result of similar responses to the loss of flight. The latest idea on dromornithid relationships, based on details of the skull, is that they evolved early in the lineage that includes waterfowl (Anseriformes). However, some phylogenetic studies have recovered them as closer to gamefowl (Galliformes).^[2]

Below is the general consensus of the phylogeny under the hypothesis that they are members of Anserimorphae.^{[10][11][12][13][14]}

Odontoanserae

†Pelagornithidae (pseudo-tooth birds)

Anserimorphae

†Gastornithidae

†Dromornithidae (mihirungs)

†Vegaviidae

Anseriformes (waterfowl)

A 2017 paper concerning the evolution and phylogeny of the giant fowl by Worthy and colleagues have found phylogenetic support in finding the mihirungs to be the sister taxon to Gastornithidae.^[9] Worthy et al. (2017) incorporated several new taxa and character traits into existing matrices of Galloanserae resulted in several of their phylogenies to support this grouping.^[9] The authors did note the bootstrap support is weakly supported and one of their phylogenies even found gastornithiforms to be stem galliforms instead.^[9] These were also weakly supported.^[9] Below is a simplified phylogeny showing their one phylogeny supporting gastornithiforms as anserimorphs.^[9]

Anserimorphae

Anseriformes (screamers and waterfowl)

†Vegaviiformes

Gastornithiformes

†Gastornithidae

†Dromornithidae (mihirungs)

A 2021 study conversely found their internal cranial anatomy more similar to that of galliforms than to anseriforms.^[15]

Species

The number of taxa in the Dromornithidae family was recognised as eight species in four genera by 2021,^[15][16] the smallest species was Barawertornis tedfordi, a bird about the size of a modern cassowary, weighing 80 to 95 kg (176 to 209 lb). The two species of Ilbandornis (Ilbandornis lawsoni and Ilbandornis woodburnei) were larger birds, but had more slender legs than the other dromornithids and were similar to ostriches in their build and size. Dromornis planei (the "demon duck of doom") and Genyornis newtoni (the "mihirung") were more heavily built, stood about 2 to 2.5 m (6.6 to 8.2 ft) tall and probably reached weights of 220 to 240 kg (490 to 530 lb). The largest dromornithids were Dromornis australis, from which the family gets its name,^[17] and the massive Dromornis stirtoni ("Stirton's thunderbird"). Genyornis is the best known of the genera.

The classification of these species has been based upon distinguishing characters of the femur, all type specimens are femurs. The cranial remains occur less frequently, with three assignable to a species level.^[3]

The placement of these dromornithid species may be summarised as:

Dromornithidae (8 species in 4 genera)^[15]

• Dromornis

• Dromornis australis Owen, 1872
• Dromornis murrayi Worthy et al., 2016^[2]
• Dromornis planei (Bullockornis planei Rich, 1979)
• Dromornis stirtoni Rich, 1979

• Barawertornis

• Barawertornis tedfordi

• Ilbandornis P. Rich, 1979

• Ilbandornis lawsoni
• Ilbandornis woodburnei

• Genyornis

• Genyornis newtoni Stirling & A. H. C. Zietz, 1896

Description and biology

Dromornithids looked superficially like very large emus or moa. Most were heavy-bodied, with powerfully developed legs and greatly reduced wings. The last bones of the toes resembled small hooves, rather than claws as in most birds. Like emus and other flightless birds, dromornithids lost the keel on the breastbone (or sternum) that serves as the attachment for the large flight muscles in most bird skeletons. Their skull also was quite different from that of emus. These birds ranged from about the size of a modern cassowary 1.5 to 1.8 m (4 ft 11 in to 5 ft 11 in) up to 3 m (9 ft 10 in) in the case of Dromornis stirtoni, possibly the largest bird that ever lived after the elephant bird (Vorombe).

Diet

It has been generally thought that the dromornithids were plant eaters, a belief currently considered common scientific consensus.^[18] This belief is based on:

• the lack of a hook at the end of the bill
• the lack of talons on the toes
• the association of gizzard stones (caveat: gastroliths are also found in the stomachs of some carnivores, such as modern crocodiles)
• the large number of individuals occurring together, suggesting flocking behaviour

Functional interpretations by researchers Warren Handley and Trevor Worthy suggests that dromornithids were specialised herbivores that likely possessed well-developed stereoscopic depth perception, were diurnal and fed on soft browse such as new growth, soft leaves, and fruit. Musculature for operation of the bill is “surprisingly limited", suggesting that these birds were not capable of a particularly forceful bite. There is no temporal fossa on the side of the cranium for insertion of mandibular musculature. The culmen in Dromornis, while large, has a lightly constructed osseous core that was only partially covered in rhamphotheca, was highly vascularised and likely highly innervated, a combination of features conferring relatively weak biting ability. This suggests that dromornithids were likely not consuming coarse browse requiring strong bite forces. ^[15]

It has been suggested that, despite the indications of herbivory in some dromornithids, Bullockornis may have been a carnivore or possibly a scavenger. However, most authorities now consider it to be a herbivore.^[18]

Locomotion

Because of their enormous size, dromornithids have been considered to have been slow, lumbering creatures. Their legs are not long and slender like those of emus or ostriches, which are specialised for running. However, biomechanical analysis of the attachments and presumed sizes of the muscles suggest that dromornithids might have been able to run much faster than originally thought, making up for their less than ideal form with brute strength.

Sexual dimorphism

Rich deposits of Dromornis stirtoni specimens, containing two forms has been determined to be evidence of sexual dimorphism within that species, the largest known. Males were more robust and heavier than females, although not necessarily taller.^[19]

Endocast studies

A 2021 study found that dromornithids had an internal cranial anatomy similar to that of galliforms.^[20]

Distribution

Records of these birds are known only from Australia. Most of the records of dromornithids come from the eastern half of the continent, although fossil evidence has also been discovered in Tasmania and Western Australia. At some Northern Territory sites they are very common, sometimes comprising 60-70% of the fossil material. A fragment of a dromornithid-sized foot bone has been found in Antarctica, but whether it represents these birds is uncertain.

The earliest bones identified were found in Late Oligocene deposits at Riversleigh in northwestern Queensland. There are foot impressions from the Early Eocene in southeastern Queensland that may be referable to dromornithids. The most recent evidence, of Genyornis newtoni, has been found at Cuddie Springs in north-central New South Wales and dated at 31,000 years old.^[21]

Extinction

The reasons for the extinction of this entire family along with the rest of the Australian megafauna by the end of the Pleistocene are still debated. It is hypothesized that the arrival of the first humans in Australia (around 48-60 thousand years ago) and their hunting and landscape-changing use of fire may have contributed to the disappearance of the megafauna. However, drought conditions during peak glaciation (about 18,000 years ago) are a significantly confounding factor. Recent studies^[22] appear to rule this out as the primary cause of extinction, but there is also some dispute about these studies.^[23] It is likely that a combination of all of these factors contributed to the megafauna's demise. However, there is significant disagreement about the relative importance of each.

Discovery

The most recent species, Genyornis newtoni, was certainly known to Aboriginal Australians during the Late Pleistocene. Cave paintings thought to depict this bird are known, as are carved footprints larger than those considered to represent emus. At Cuddie Springs, Genyornis bones have been excavated in association with human artifacts. The issue of how much of an impact humans had on dromornithids and other large animals of the time is unresolved and much debated. Many scientists believe that human settlement and hunting were largely responsible for the extinction of many species of the Australian megafauna.

The first Europeans to encounter the bones of dromornithids may have been Thomas Mitchell and his team. While exploring the Wellington Caves, one of his men tied his rope to a projecting object which broke when he tried to descend the rope. After the man had climbed back up, it was found that the projecting object was the fossilised long bone of a large bird. The first species to be described was Dromornis australis. The specimen was found in a 55-metre deep well at Peak Downs, Queensland, and subsequently described by Richard Owen in 1872.

Extensive collections of any dromornithid fossils were first made at Lake Callabonna, South Australia.

In 1892, E. C. Stirling and A. H. C. Zietz of the South Australian Museum received reports of large bones in a dry lake bed in the northwest of the state. Over the several next years, they made several trips to the site, collecting nearly complete skeletons of several individuals. They named the newly found species Genyornis newtoni in 1896. Additional remains of Genyornis have been found in other parts of South Australia and in New South Wales and Victoria.

Other sites of importance were Bullock Creek and Alcoota, both in the Northern Territory. The specimen recovered there remained unstudied and unnamed until 1979, when Patricia Rich described five new species and four new genera.^[16]

The best represented bones of dromornithids are vertebrae, long bones of the hindlimb and toe bones. Ribs and wing bones are uncommonly preserved. The rarest part of the skeleton is the skull. For many years, the only skull known was a damaged specimen of Genyornis. Early reconstructions of dromornithids made them appear like oversized emus. Peter Murray and Dirk Megirian of Australia's Northern Territory Museum recovered enough skull material of Bullockornis to give a good idea of what that bird's head looked like. It is now known that the Bullockornis skull was very large, with the enormous bill making up about two-thirds of it. The bill was deep, but rather narrow. The jaws had cutting edges at the front, as well as crushing surfaces at the back. There were attachments for large muscles, indicating that Bullockornis had a powerful bite. More fragmentary remains of the skull of Dromornis suggest that it, too, had an oversized skull.

Bones are not the only remains of dromornithids that have been found:

• The polished stones that the birds kept in their gizzards (muscular stomachs) occur at a number of sites. These stones, called gastroliths, played an important role in their digestion by breaking up coarse food or matter that was swallowed in large chunks.
• Series of footprints, called trackways, have been found at several sites.^[24][25][26]
• Impressions of the inside of the skull cavity (endocranial casts or endocasts) have been found. Endocasts are formed when sediments fill the empty skull, after which the skull is destroyed. These fossils give a fairly accurate picture of dromornithid brains.

See also

• Fossil birds
• Later Quaternary Prehistoric Birds

Notes

References

• 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.
• Miller, G. H.; Magee, J. W.; Johnson, B. J.; Fogel, M. L.; Spooner, N. A.; McCulloch, M. T.; Ayliffe, L. K. (1999). "Pleistocene extinction of Genyornis newtoni: human impact on Australian megafauna". Science. 283 (#5399): 205–208. doi:10.1126/science.283.5399.205. PMID 9880249.
• 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.
• Murray, Peter; Vickers-Rich, Patricia (2004). Magnificent mihirungs : the colossal flightless birds of the Australian dreamtime. Bloomington: Indiana University Press. ISBN 978-0-253-34282-9.
• Rich, P (1979). "The Dromornithidae, an extinct family of large ground birds endemic to Australia" (PDF). Bulletin of the Bureau of Mineral Resources, Geology and Geophysics. 184: 1–190.
• Rich, P.; Gill, E. (1976). "Possible dromornithid footprints from Pleistocene dune sands of southern Victoria, Australia". Emu. 76 (#4): 221–223. doi:10.1071/mu9760221.
• Rich, P.; Green, R. H. (1974). "Footprints of birds at South Mt Cameron, Tasmania". Emu. 74 (#4): 245–248. doi:10.1071/mu974245.
• Roberts, R. G.; Flannery, T. F.; Ayliffe, L. A.; Yoshida, H.; Olley, J. M.; Prideaux, G. J.; Laslett, G. M.; Baynes, A.; Smith, M. A.; Jones, R.; Smith, B. L. (2001). "New ages for the last Australian megafauna: continent-wide extinction about 46,000 years ago". Science. 292 (#5523): 1888–1892. Bibcode:2001Sci...292.1888R. doi:10.1126/science.1060264. PMID 11397939. S2CID 45643228.
• Vickers-Rich, P.; Molnar, R. E. (1996). "The foot of a bird from the Eocene Redbank Plains Formation of Queensland, Australia". Alcheringa. 20: 21–29. doi:10.1080/03115519608619220.
• Williams, D. L. G. (1981). "Genyornis eggshell (Dromornithidae; Aves) from the Late Pleistocene of South Australia". Alcheringa. 5 (#2): 133–140. doi:10.1080/03115518108565426.
• Williams, D. L. G.; Vickers-Rich, P. (1992). "Giant fossil egg fragment from the Tertiary of Australia". Contributions in Science, Natural History Museum of Los Angeles County. 36: 375–378.

La Dromornitedoj aŭ laŭ la latina scienca nomo Dromornithidae estis klado de grandaj, neflugaj aŭstraliaj birdoj el la Oligoceno tra Pleistoceno. Ĉiuj estas nune formortintaj. Ili estis dumlonge klasitaj en la Strutoformaj, sed estas nune kutime klasitaj kiel Anseroformaj.^[1][2]

La Dromornitedoj estis parto de la Aŭstralia megafaŭno. Unu specio, Dromornis stirtoni, estis 3 m alta. La kolektiva termino Aŭstralia megafaŭno estas uzata por priskribi nombron de kompare grandaj specioj de animaloj kiuj loĝis en Aŭstralio ĝis antaŭ 50,000 al 20,000 jaroj. La tialoj por ties malapero estas ankoraŭ disputita.^[3][4]

Ne klaras ankaŭ ĝis kioma grado la Dromornitedoj estis karnovoruloj. La fortika, premega beko de kelkaj specioj sugestas, ke almenaŭ kelkaj membroj de la familio estis kombino de karnovoraj predantoj kaj kadavromanĝantoj (multe kiel nunaj hienoj) aŭ ĉiomanĝantoj. Aliaj karakteroj, kiaj "hufecaj" piedoj, stomaka strukturo, kaj okula strukturo kio rezultis en ampleksa vidkampo sed ankaŭ verŝajne en kreo de nevidebla punkto de ĉirkaŭ 40 gradoj (kiu ege estus malhelpinte ĉasadon) sugestas pli herbovoran, migrantan vivostilon.

La scienca nomo Dromornithidae derivas el grekaj dromaios ("rapidkura") kaj ornis ("birdo"). Aldone, la familio estis nomata ŝtormobirdoj, gigantaj emuoj, gigantaj kuruloj, diablanasoj kaj mihirungoj.

Specioj

Estas 7 specioj en Dromornitedoj,^[5] el kiuj la plej malgranda specio estis Barawertornis tedfordi, nome birdo ĉirkaŭ samgranda kun moderna kazuaro, pezas 80 al 95 kg. La du specioj de Ilbandornis (Ilbandornis lawsoni kaj Ilbandornis woodburnei) estis pli grandaj birdoj, sed havis pli sveltajn krurojn ol la aliaj Dromornitedoj kaj estis similaj al strutoj laŭ konstruo kaj grando. Bullockornis planei] kaj Genyornis newtoni (mihirungo) estis pli fortikaj, stare ĉirkaŭ 2| al 2.5 m altaj kaj probable atingis pezojn de 220 al 240 kg. La plej grandaj dromornitedoj estis Dromornis australis kaj la amasa Dromornis stirtoni. Genyornis esas la plej bone konata genro.

• Artista rekonstruo de Genyornis newtoni.

• Artista rekonstruo de Dromornis stirtoni.

Notoj

Referencoj

• 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: 177-188.

• 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.

• Murray, P. F. & Vickers-Rich, P. (2004) Magnificent Mihirungs: The Colossal Flightless Birds of the Australian Dreamtime. Indiana University Press.

• Miller, G. H. Magee, J. W. Johnson, B. J. Fogel, M. L. Spooner, N. A. McCulloch, M. T. & Ayliffe, L. K. (1999) Pleistocene extinction of Genyornis newtoni: human impact on Australian megafauna. Science 283: 205-208. COI:10.1126/science.283.5399.205

• Rich, P. (1979) The Dromornithidae, an extinct family of large ground birds endemic to Australia. Bulletin of the Bureau of Mineral Resources, Geology and Geophysics 184: 1-190.

• Rich, P. & Gill, E. (1976) Possible dromornithid footprints from Pleistocene dune sands of southern Victoria, Australia. Emu 76: 221-223.

• Rich, P. & Green, R. H. (1974) Footprints of birds at South Mt Cameron, Tasmania. Emu 74: 245-248.

• Roberts, R. G. Flannery, T. F. Ayliffe, L. A. Yoshida, H. Olley, J. M. Prideaŭ, G. J. Laslett, G. M. Baynes, A. Smith, M. A. Jones, R. & Smith, B. L. (2001) New ages for the last Australian megafauna: continent-wide extinction about 46,000 years ago. Science 292: 1888-1892. COI:10.1126/science.1060264

• Vickers-Rich, P. & Molnar, R. E. (1996) The foot of a bird from the Eocene Redbank Plains Formation of Queensland, Australia. Alcheringa 20: 21-29.

• Williams, D. L. G. (1981) Genyornis eggshell (Dromornithidae; Aves) from the Late Pleistocene of South Australia. Alcheringa 5: 133-140.

• Williams, D. L. G. & Vickers-Rich, P. (1992) Giant fossil egg fragment from the Tertiary of Australia. Contributions to Science, Natural History Museum of Los Angeles County 36: 375-378.

Los dromornítidos (Dromornithidae) son una familia extinta de aves no voladoras gigantes que habitaron el continente australiano entre el Oligoceno y Pleistoceno. Se clasificaron como ratites cuando se descubrieron. Sin embargo, se recatalogaron como anseriformes, siendo parientes distantes de aves acuáticas como los patos y gansos.

Estas aves formaron parte de la megafauna australiana,^[2]​ es decir, que fue un animal de mínimo 30 kilogramos que pobló Sahul aproximadamente hasta el Pleistoceno.^[3]​^[4]​

Las causas de su extinción no son claras, pero existen varias teorías. La más convincente es que desapareció por la llegada de los seres humanos al territorio australiano. Tampoco se sabe con seguridad su régimen alimentario; en principio se pensó que eran herbívoros. Sin embargo, ahora los biólogos y paleontólogos que lo han investigado declaran una dieta carnívora. Otros sugieren que la familia de anseriformes fueron, dependiendo de la especie, omnívora o carnívora depredadora y carnívora carroñera (similar a la dieta de las hienas).

Son parecidos a los emús, avestruces y moas. Sus alas son muy reducidas en proporción al cuerpo y sus patas extremadamente largas y gruesas, lo que le ayuda a alcanzar una velocidad realmente ágil y veloz. Su pico es también desproporcionadamente grande, posiblemente para poder desgarrar presas de un picotazo (parecidas a las Aves del Terror). No obstante, su pico no tiene forma de gancho, lo que lleva a pensar que su dieta es herbívora. Carece de garras en las pezuñas y se cree que vivían en manadas.

Etimología

Su nombre científico (Dromornithidae) proviene del griego: dromaios (rápido, corredor), y ornis (pájaro). Los nombres comunes para esta ave son "el ave del infierno", "el pájaro estampida" y el más famoso, "El emú gigante".

Especies

El género más extendido, conocido y estudiado es Genyornis. Esta es probablemente carnívora, por la forma de su pico. El miembro más pequeño de la familia es Barawertornis tedfordi, del tamaño aproximado de un casuario y de unos 80 kg. Mucho mayor es Ilbandornis (2 m), un género que cuenta con dos especies: Ilbandornis lawsoni e Ilbandornis woodburnei. Son de piernas más delgadas y del tamaño y forma de un avestruz. Ambas especies fueron encontradas en Alcoota y datan del Mioceno. Las formas de mayor tamaño se clasifican en el género Dromornis y en particular la especie Dromornis stirtoni.

Bullockornis planei, la única especie de su género (Bullockornis) es una de las más corpulentas. Llegaban a pesar hasta los 240 kg y medir unos 2 m.

• Dromornis †

• Dromornis australis †
• Dromornis stirtoni †
• Dromornis murrayi †

• Barawertornis †

• Barawertornis tedfordi †

• Bullockornis †

• Bullockornis planei †

• Ilbandornis †

• Ilbandornis lawsoni †
• Ilbandornis woodburnei †

• Genyornis †

• Genyornis newtoni †

Dieta

Para reconocer el régimen alimentario de un animal extinto, se realizan investigaciones en su forma esquelética y locomotora. El caso de los Dromornithidae es desconcertante, ya que se observan características carnívoras, omnívoras y herbívoras. En un principio se creía que eran herbívoras por la falta de garras en las patas, por no tener pico con forma de gancho, por su comportamiento agrupativo (en manadas) y por una característica clave: tener gastrolitos en el estómago.^[5]​ Los gastrolitos son pequeñas piedras ovaladas que ingieren de forma natural algunos animales para la mejor trituración de los alimentos que engullen. Los animales que utilizan este método digestivo son: cocodrilos, pinípedos, cetáceos y aves herbívoras. No obstante, se han encontrado también en dinosaurios carnívoros.

Posteriormente, se formuló la idea de que fueran unas aves carnívoras emparentadas con las aves sudamericanas de la familia Phorusrhacidae (Aves del terror). La vinculación con estas se demostró incorrecta, pero su dieta está en debate aún.

Actualmente, la cuestión alimenticia de este animal extinto se ha esclarecido y se ha llegado a la conclusión de que no todas las aves de la familia siguen la misma conducta alimentaria. Genyornis era con toda seguridad, herbívora. En 2005 se encontraron en la cáscara del huevo del género restos de aminoácidos que demostraban que Genyornis era herbívora. El género Bullockornis, sin embargo, aparenta ser carnívoros carroñeros; su potente mandíbula podría cortar carne fácilmente. Esta ave podría haberse alimentado de los cadáveres de animales grandes. El cráneo de Bullockornis es muy grande y el pico muy profundo. Esto es muy diferente a las grandes aves herbívoras como las moas. Si Bullockornis comía plantas, estaba equipados con una estructura muscular y ósea demasiado potente, para ingerir materiales que hasta ahora no han sido identificados.

Referencias

Dromornithidae on sukupuuttoon kuollut lentokyvyttömien lintujen heimo. Ne elivät Australiassa neogeenikaudella, mutta ovat nykyään kuolleet sukupuuttoon. Niiden luultiin kauan kuuluvan strutsilintuihin, mutta nykyään ne on luokiteltu sorsalintuihin. Läheisimmät elävät sukulaiset ovat sorsat. Nimi Dromornithidae tulee kreikan kielen sanoista dromaios (tarkoittaa nopeaa juoksijaa) ja ornis (tarkoittaa lintua). Dromornithidae-heimon linnut olivat suurikokoisia ja Dromornis stirtoni kasvoi jopa yli 3-metriseksi. Heimo tunnetaan suuresta nokasta, jota käytettiin ainakin siementen murskaamiseen.

Ulkonäkö

Dromornithidae-heimon jäsenet näyttivät suurilta emuilta tai moailta. Useimmat olivat raskasrakenteisia, joilla oli voimakkaat jalat ja suuresti supistuneet siivet. Viimeiset luut varpaissa muistuttivat enemmän pieniä kavioita kuin kynsiä. Nämä linnut kasvoivat 1,5-metrisistä jopa 3-metrisiin (Dromornis stirtoni, luultavasti suurin elänyt lintu).

Lajit

Vuonna 2005 viisi sukua ja seitsemän lajia oli löydetty, ja ainakin yksi uusi suku on työn alla. Pienin heimon laji oli luultavasti Barawertornis tedfordi, joka painoi 80–95 kg. Kaksi Ilbandornis-suvun lajia (Ilbandornis lawsoni ja Ilbandornis woodburnei) olivat suurempia, mutta heikompijalkaisia kuin muut dromornithidae-heimon jäsenet. Bullockornis planei ja Genyornis newtoni olivat raskasrakenteisia ja 2–2,5 m pitkiä ja ne painoivat noin 220–240 kg. Suurimmat heimon linnut olivat Dromornis-suvun Dromornis australis ja Dromornis stirtoni.

Levinneisyys

Dromornithidae-heimon jäseniä on toistaiseksi löydetty vain Australiasta. Suurin osa löydöistä on löytynyt mantereen itäosista, tosin myös Länsi-Australiasta ja Tasmaniasta on löydetty fossiileja. Pohjoisterritoriosta on löydetty usein juuri Dromornithidae-heimon fossiileja.

Les Dromornithidae formaient une famille de gros oiseaux de la mégafaune australienne, non volants et ayant vécu à l'Oligocène et au Pléistocène. Longtemps classés parmi les Struthioniformes, ils sont désormais placés parmi les Anseriformes^[1].

Références taxinomiques

• (en) Référence Paleobiology Database : Dromornithidae Fürbringer 1888

Notes et références

I dromornitidi (Dromornithidae), altrimenti noti con il nome aborigeno di mihirungs, sono un gruppo di uccelli noti esclusivamente allo stato fossile, vissuti in Australia tra l'Oligocene e il Pleistocene (tra 35 milioni di anni fa e 10.000 anni fa).

Gli uccelli giganti dell'Australia

Inetti al volo, questi uccelli avevano un'altezza compresa tra un metro e mezzo e tre metri. Le forme più grandi, come Dromornis stirtoni del Miocene superiore, potevano sfiorare i 500 kg di peso ed erano tra i più grandi uccelli mai esistiti, di dimensioni paragonabili a quelle dell'uccello elefante del Madagascar o dei moa della Nuova Zelanda. In generale, i mihirungs erano dotati di zampe posteriori lunghe e poderose, un corpo compatto e le ali atrofizzate. Il cranio, conosciuto per frammenti fino agli anni '90, è ben noto solo per Bullockornis planei del Miocene inferiore. Questo cranio, contrariamente a quanto fino a quel momento ritenuto, è alto e grosso, dotato di un poderoso becco, che lo faceva assomigliare vagamente alla testa dei grandi uccelli gastornithidi dell'Eocene, come Gastornis. Probabilmente Bullockornis e le forme simili dovevano essere carnivori, e rappresentavano i massimi predatori del loro ecosistema.

Grandi oche carnivore?

Fin a pochi anni fa i mihirungs erano ritenuti stretti parenti dei casuari e degli emù, soprattutto in base a presunte somiglianze dello scheletro. I resti del cranio di Bullockornis hanno invece evidenziato insospettabili parentele con le anatre e le oche (Anseriformes). La forma più antica di dromornitide, e anche la più piccola, è Barawertornis, dell'Oligocene. Tra i dromornitidi vi erano forme dalla corporatura pesante (Bullockornis e Dromornis) e altre dalla corporatura snella, probabilmente veloci corridori (Ilbandornis). L'ultimo genere noto, Genyornis, si estinse alla fine del Pleistocene e fu contemporaneo dei primi esseri umani abitatori dell'Australia.

Bibliografia

• Archer, M. (1999): Brain of the demon duck of doom. Nature Australia 26(7): 70-71.
• Clarke, W. B. (1877): On Dromornis Australis (Owen), a new fossil bird of Australia. Journal of the Proceedings of the Royal Society of New South Wales 11: 41-49.
• 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: 177-188.
• Jennings, S. F. (1990): The musculoskeletal anantomy [sic], locomotion and posture of the dromornithid Dromornis stirtoni from the Late Miocene Alcoota Local Fauna. Unpublished Honours Thesis, School of Biological Sciences, Flinders University of South Australia.
• 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.
• Miller, G. H.; Magee, J. W.; Johnson, B. J.; Fogel, M. L.; Spooner, N. A.; McCulloch, M. T. & Ayliffe, L. K. (1999): Pleistocene extinction of Genyornis newtoni: human impact on Australian megafauna. Science 283: 205-208. DOI: 10.1126/science.283.5399.205 (HTML abstract)
• Owen, R. (1872): [Untitled]. Proceedings of the Zoological Society of London 1872: 682-683.
• Pain, S. (2000): The demon duck of doom. New Scientist 166(2240): 36-39.
• Rich, P. (1979): The Dromornithidae, an extinct family of large ground birds endemic to Australia. Bulletin of the Bureau of Mineral Resources, Geology and Geophysics 184: 1-190.
• Rich, P. (1980): The Australian Dromornithidae: a group of extinct large ratites. Contributions to Science, Natural History Museum of Los Angeles County 330: 93-103.
• Rich, P. (1985): Genyornis newtoni Stirling and Zietz, 1896. A mihirung. In: Rich, P. V. & van Tets, G. F. (eds.): Kadimakara: Extinct Vertebrates of Australia, Pp. 188–194. Pioneer Design Studios, Lilydale, Victoria.
• Rich, P. & Gill, E. (1976): Possible dromornithid footprints from Pleistocene dune sands of southern Victoria, Australia. Emu 76: 221-223.
• Rich, P. & Green, R. H. (1974): Footprints of birds at South Mt Cameron, Tasmania. Emu 74: 245-248.
• R. G. Roberts, New Ages for the Last Australian Megafauna: Continent-Wide Extinction About 46,000 Years Ago, in Science, vol. 292, n. 5523, 8 giugno 2001, pp. 1888–1892, DOI:10.1126/science.1060264. Supplementary Data Erratum: Corrections and Clarifications, in Science, vol. 293, n. 5527, 6 luglio 2001, pp. 49b–49, DOI:10.1126/science.293.5527.49b.
• Stirling, E. C. (1913). Fossil remains of Lake Callabonna. Part IV. 1. Description of some further remains of Genyornis newtoni, Stirling and Zietz. Memoirs of the Royal Society of South Australia 1: 111-126.
• Stirling, E. C. & Zietz, A. H. C. (1896). Preliminary notes on Genyornis newtoni: a new genus and species of fossil struthious bird found at Lake Callabonna, South Australia. Transactions of the Royal Society of South Australia 20: 171-190.
• Stirling, E. C. & Zietz, A. H. C. (1900). Fossil remains of Lake Callabonna. I. Genyornis newtoni. A new genus and species of fossil struthious bird. Memoirs of the Royal Society of South Australia 1: 41-80.
• Stirling, E. C. & Zietz, A. H. C. (1905). Fossil remains of Lake Callabonna. Part III. Description of the vertebrae of Genyornis newtoni. Memoirs of the Royal Society of South Australia 1: 81-110.
• Vickers-Rich, P. & Molnar, R. E. (1996). The foot of a bird from the Eocene Redbank Plains Formation of Queensland, Australia. Alcheringa 20: 21-29.
• Williams, D. L. G. (1981). Genyornis eggshell (Dromornithidae; Aves) from the Late Pleistocene of South Australia. Alcheringa 5: 133-140.
• Wroe, S. (1999): The bird from hell? Nature Australia 26(7): 56-63.
• Wroe, S.; Field, J. & Fullagar, R. (2002): Lost giants. Nature Australia 27(5): 54-61.

De Dromornithidae zijn familie van uitgestorven niet-vliegende vogels uit Australië. De groep behoort tot de eendachtigen. De Dromornithidae worden ook wel dondervogels of mihirungs genoemd. Deze laatste naam is afgeleid van het Djab Wurrung mihirung paringmal, wat reuzenemoe betekent en een term is die voorkomt in Aboriginal-legendes. De Dromornithidae leefden van het Laat-Oligoceen tot in het Pleistoceen.

Classificatie

De eerste fossielen van de Dromornithidae werden in 1839 gevonden en ze werden geduid als een verwant van de hedendaagse loopvogels. Latere vondsten gaven meer duidelijkheid over de verwantschap van de dondervogels. Ze worden tegenwoordig als verwant aan de eendachtigen beschouwd, wat de groep de bijnaam demon ducks opleverde.

Uiterlijk en leefwijze

De dondervogels leken uiterlijk enigszins op hedendaagse loopvogels met een zwaargebouwd lichaam, robuuste poten en rudimentaire vleugels. Aan de tenen van de dondervogels zaten hoefachtige uiteinden. In grootte varieerden de dondervogels van anderhalve meter, het formaat van een hedendaagse kasuaris, tot drie meter hoog. Biomechanische studies wijzen er op dat de dondervogels relatief snelle dieren waren. De maximale loopsnelheid van Dromornis wordt geschat op 35 km/u. Het voedingspatroon van de dondervogels is een punt van discussie. De huidige gedachte is dat het voedingspatroon niet voor alle dondervogels hetzelfde was. In het geval van Genyornis zijn er meerdere aanwijzingen voor een herbivoor dieet. Analyse van aminozuren in de eischalen ondersteunen een herbivore leefwijze en fossielen van Genyornis zijn in enkele afzettingen in grote aantallen gevonden, wat erg ongewoon is voor roofdieren. Bullockornis en Dromornis hadden grotere en krachtigere snavel en schedel dan de andere dondervogels met aanwijzingen voor krachtige kaakspieren, wat het best past bij een carnivore leefwijze als actieve jager of aaseter.

Soorten

Er zijn vijf bekende geslachten dondervogels en zeven bekende soorten:

Geslacht Barawertornis

• • Barawertornis tedfordi

Geslacht Bullockornis

• • Bullockornis planei

Geslacht Dromornis

• • Dromornis australis
  • Dromornis stirtoni

Geslacht Genyornis

• • Genyornis newtoni

Geslacht Ilbandornis

• • Ilbandornis lawsoni
  • Ilbandornis woodburnei

Fossielen die toebehoren aan dondervogels, maar niet tot op soort- of geslachtsniveau geclassificeerd kunnen worden zijn onder meer in Redbank Plains in Queensland (Vroeg-Eoceen), Endurance Mine in Tasmanië (Laat-Oligoceen/Vroeg-Mioceen) en Mammoth Cave in Western Australia (Pleistoceen) gevonden.

Multimedia w Wikimedia Commons

Dromornithidae – rodzina bardzo dużych, nielotnych i wymarłych ptaków z rzędu blaszkodziobych. Występowały w Australii 50 000–20 000 lat temu.

Do rodziny zaliczono 5 rodzajów i 7 gatunków:

• Rodzaj: Barawertornis
  • Barawertornis tedfordi
• Rodzaj: Ilbandornis
  • Ilbandornis lawsoni
  • Ilbandornis woodburnei
• Rodzaj: Bullockornis
  • Bullockornis planei
• Rodzaj: Genyornis
  • Genyornis newtoni
• Rodzaj: Dromornis
  • Dromornis australis
  • Dromornis stirtoni

Dromornithidae é uma família extinta de aves não-voadoras da ordem Anseriformes. Endêmica da Austrália, ocorreu do Oligoceno ao Pleistoceno, quando foram extintas juntamente com o restante da megafauna australiana.

A alimentação dessas aves é um mistério. Enquanto algumas, como o Genyornis, aparentam ter tido uma alimentação essencialmente herbívora, outras como o Dromornis stirtoni, podem ter sido carnívoras. E há ainda outras que podem ter sido onívoras ou carniçeiras. O Dromornis stirtoni foi possivelmente a maior ave que já viveu.

Nomenclatura e taxonomia

A família foi descrita por Max Fürbringer em 1888, que a incluiu em uma ordem própria, a Dromornithiformes, dentro da Paleognathae. Murray e Megirian (1998) com base em características osteológicas craniais classificaram-na dentro da ordem Anseriformes, como o clado-irmão da família Anhimidae.^[1]

A família possui 5 gêneros e 7 espécies:^[2]

• Gênero †Barawertornis Rich, 1979
  • †Barawertornis tedfordi Rich, 1979
• Gênero †Bullockornis Rich, 1979
  • †Bullockornis planei Rich, 1979
• Gênero †Dromornis Owen, 1872
  • †Dromornis australis Owen, 1872
  • †Dromornis stirtoni Rich, 1979
• Gênero †Genyornis Stirling & Zietz, 1896
  • †Genyornis newtoni Stirling & Zietz, 1896
• Gênero †Ilbandornis Rich, 1979
  • †Ilbandornis lawsoni Rich, 1979
  • †Ilbandornis woodburnei Rich, 1979

Referências

Dromornithidae var en familj av stora andfåglar som levde i Australien och på Tasmanien. De saknade flygförmåga och kallas i Australien även för Mihirung. De äldsta fossilen är ungefär 20 miljoner år gamla.

Arterna i släktet Dromornis blev upp till 3 meter höga och över en ton tunga. Genyornis newtoni levde fram till pleistocen och var känd för aboriginerna. Fynd av ben i samhällen visar att den jagades av Australiens ursprungsbefolkning. Arten dog ut för cirka 26 000 år sedan.

Orsaken till arternas utdöende förmodas vara klimatförändringar, buskbränder och människans jakt.

Arter

Familjen består av sju arter fördelade på fem släkten:

• Barawertornis tedfordi Rich, 1979
• Ilbandornis
  • Ilbandornis lawsoni Rich, 1979
  • Ilbandornis woodburnei Rich, 1979
• Bullockornis planei Rich, 1979
• Genyornis newtoni Stirling & Zietz, 1896
• Dromornis
  • Dromornis australis Owen, 1872
  • Dromornis stirtoni Rich, 1979

Referenser

Den här artikeln är helt eller delvis baserad på material från tyskspråkiga Wikipedia, 26 maj 2009.

• Alan Feduccia: The Origin and Evolution of the Birds. 2. Aufl., Yale University Press, New Haven/ London, 1999, ISBN 0300078617
• Peter F. Murray: Magnificent Mihirungs: The Colossal Flightless Birds of the Australian Dreamtime. Indiana University Press, 2003, ISBN 0253342821

Externa länkar

• Wikimedia Commons har media som rör Dromornithidae.
  Bilder & media
• 'Thunder Birds' - The Family Dromornithidae på Australian Museum online
• Stephen Wroe: The Bird From Hell? Nature Australia, Volume 26, no 7:56 - 63 online

• 1 Етимологія
• 2 Класифікація
• 3 Див. також
• 4 Література

Dromornis là một chi chim tiền sử cao hơn 3 mét (10 feet) và nặng hơn nữa tấn.

Môi trường sống và hành vi

Nó sống ở rừng cận nhiệt đới mở tại Úc vào cuối thế Miocene và có thể đã ăn thịt. Có rừng và nguồn cung cấp nước thường trực tại Alcoota, một địa điểm nơi Dromornis chim sống, mặc dù khí hậu rất khó lường. Dromornis sống ở Úc từ Miocene muộn đến Pliocene sớm có nghĩa là con người không bao giờ gặp phải chi này. Dromornis có một mỏ lớn và có lực cắn lớn.

Chú thích

Tham khảo

• Dữ liệu liên quan tới Dromornis tại Wikispecies
• Murray, P. F. Vickers-Rich, P. (2004) Magnificent Mihirungs: The Colossal Flightless Birds of the Australian Dreamtime. Indiana University Press. ISBN 978-0-253-34282-9.
• Ellis, R. (2004) No Turning Back: The Life and Death of Animal Species. New York: Harper Perennial. p. 102. ISBN 0-06-055804-0.

Царство: Животные

Подцарство: Эуметазои

Без ранга: Двусторонне-симметричные

Без ранга: Вторичноротые

Тип: Хордовые

Подтип: Позвоночные

Инфратип: Челюстноротые

Надкласс: Четвероногие

Класс: Птицы

Подкласс: Настоящие птицы

Инфракласс: Новонёбные

Отряд: Гусеобразные

Семейство: † Dromornithidae

• 1 Этимология
• 2 Классификация
• 3 Примечания
• 4 Литература

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