| Australornis | |
|---|---|
Scientific classification | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Aves |
| Order: | Anseriformes |
| Family: | †Vegaviidae (?) |
| Genus: | †Australornis Mayr & Scofield, 2014 |
| Type species | |
| Australornis lovei Mayr & Scofield, 2014 | |
Australornis (Latin: "southern bird") is agenus ofextinctseabird discovered inNew Zealand.[1] It lived in thePaleocene epoch, 60.5 to 61.6 million years ago (Ma).[1] Thetype species name originates fromaustralis, Latin for "southern", andornis, the Greek word for "bird", andlovei commemorates Leigh Love, an amateur paleontologist who discovered it.[1][2]
Australornis is one of the oldest flying seabirds.[3] It is also the first non-sphenisciform (penguins and allies) bird fossil discovered from New Zealand for that age.[2] The fossil originates from an era just after theCretaceous–Paleogene extinction event 66 million years ago.[1] The features of the bird indicate that it does not belong to any of the extant bird families, but to a precursor group orclade which is extinct; hence it is a find of global significance with regard to theevolution of birds.[3] Though the fossil evidence is incomplete to substantiate phylogeny,Australornis contributes to the emerging view that the diversification of Neoaves had already begun in the earliest Paleogene.[1]
Australornis is also ofzoogeographical significance, as New Zealand was much closer toAntarctica during theLate Cretaceous andEarly Paleocene and it would have originated over deep waters of a warm sea off the coast ofZealandia, now a nearly submerged continent or microcontinent that sank after breaking away from Australia between 60 and 85 million years ago and on which New Zealand rests.[2]
The fossil was discovered in 2009 by Leigh Love in thePaleoceneWaipara Greensand of northCanterbury on theSouth Island ofNew Zealand.[4][5]
The fossil was deposited in theCanterbury Museum, Christchurch, where it lay in museum shelves for a number of years, as earthquakes severely affected the working of the Museum staff.[2] The fossil was described in 2014 by Dr Gerald Mayr, from theSenckenberg Research Institute and Natural History Museum inFrankfurt-am-Main, and Dr Paul Scofield of the Canterbury Museum, who published their findings in theJournal of the Royal Society of New Zealand.[2]
Australornis grew roughly to about 70 to 85 centimetres (28 to 33 in) long,[3] and has been likened to apied shag in size.[2] It is thought to have weighed between 1.5 to 2 kilograms (3.3 to 4.4 lb).[3]
Australornis is known from the following remains:[1]
The wing and pectoral girdle bones of this avian fossil have been found to be quite distinct. While there is not enough fossil material fromAustralornis to enable a phylogenetic study linking it with extant bird groups, it has been found to share certainderived characteristics with a number of modern bird taxonomic groups, namelyProcellariiformes,Gaviiformes andRallidae.[1][5]
Australornis lovei has similarities to two fossil avians from Antarctica - the similarly-sizedVegavis iaai (Noriega & Tambussi 1995) from the late Cretaceous (68 - 66 Ma) ofVega Island, Antarctica andPolarornis gregorii (Chatterjee 2002) from theLate CretaceousLópez de Bertodano Formation ofSeymour Island of Antarctica.[1]
ThoughAustralornis was found near the fossils ofWaimanu manneringi, the oldest fossil penguin, found in the same level of strata in Waipara and regarded to be of the same age, it lacks any morphological resemblances to penguins.[5] In 2017 a phylogenetic study Agnolín and colleagues have foundAustralornis to be stem-anseriforms along withPolarornis,Neogaeornis andVegavis in the familyVegaviidae.[6]
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