''Sylviornis'', also known by its native name of Du, is an extinct

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

of large, flightless bird that was endemic to the islands of New Caledonia in the Western Pacific. It is considered to constitute one of two genera in the extinct

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

Sylviornithidae, alongside '' Megavitiornis'' from Fiji, which are related to the

Galliformes Galliformes is an order of heavy-bodied ground-feeding birds that includes turkeys, chickens, quail, and other landfowl. Gallinaceous birds, as they are called, are important in their ecosystems as seed dispersers and predators, and are ofte ...

, the group containing the

turkeys The turkey is a large bird in the genus ''Meleagris'', native to North America. There are two extant turkey species: the wild turkey (''Meleagris gallopavo'') of eastern and central North America and the ocellated turkey (''Meleagris ocellat ...

, chickens,

quails Quail is a collective name for several genera of mid-sized birds generally placed in the order Galliformes. The collective noun for a group of quail is a flock, covey, or bevy. Old World quail are placed in the family Phasianidae, and New Wor ...

and

pheasants Pheasants ( ) are birds of several genera within the family Phasianidae in the order Galliformes. Although they can be found all over the world in introduced (and captive) populations, the pheasant genera native range is restricted to Eurasia ...

. ''Sylviornis'' was never encountered alive by

scientists A scientist is a person who conducts scientific research to advance knowledge in an area of the natural sciences. In classical antiquity, there was no real ancient analog of a modern scientist. Instead, philosophers engaged in the philosophica ...

, but it is known from many thousands of subfossil bones found in deposits, some of them from the

Holocene The Holocene ( ) is the current geological epoch. It began approximately 11,650 cal years Before Present (), after the Last Glacial Period, which concluded with the Holocene glacial retreat. The Holocene and the preceding Pleistocene togeth ...

, on New Caledonia and the adjacent Île des Pins. It was likely hunted to extinction shortly after the first human arrival to New Caledonia around 1500 BC.

Description

''Sylviornis'' was a huge flightless bird, standing up to tall, and weighing around on average. In the 2016 study, its height in resting stance was estimated up to , while its mass estimate decreased to . It is the most massive

galliform Galliformes is an order of heavy-bodied ground-feeding birds that includes turkeys, chickens, quail, and other landfowl. Gallinaceous birds, as they are called, are important in their ecosystems as seed dispersers and predators, and are often ...

known to have ever existed. It had a large skull with a high and laterally compressed beak surmounted by a bony knob. Its legs were rather short, but had strong toes with long nails. The skeleton has a number of peculiarities and differences that make ''Sylviornis'' stand apart from all other known birds: the

clavicle The clavicle, or collarbone, is a slender, S-shaped long bone approximately 6 inches (15 cm) long that serves as a strut between the shoulder blade and the sternum (breastbone). There are two clavicles, one on the left and one on the r ...

s were not fused to a

furcula The (Latin for "little fork") or wishbone is a forked bone found in most birds and some species of non-avian dinosaurs, and is formed by the fusion of the two pink clavicles. In birds, its primary function is in the strengthening of the thoracic ...

, the number of caudal

vertebra The spinal column, a defining synapomorphy shared by nearly all vertebrates, Hagfish are believed to have secondarily lost their spinal column is a moderately flexible series of vertebrae (singular vertebra), each constituting a characteristi ...

e was very high, and the ribcage and pelvis were almost

dinosaur Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the evolution of dinosaurs is t ...

ian in appearance. The wings were reduced to small stubs.

Behaviour

A large proportion—up to 50% in some deposits—of the remains found were from juvenile animals. Thus, it has been theorized that ''Sylviornis'' had a clutch of at least two, more probably closer to 10 eggs, and that the average lifespan was not much more than 5–7 years, which would be extremely low for such a large bird. It was thought that the bird did not incubate its eggs but built a mound similar to the megapodes. Tumuli on the Île des Pins which were initially believed to be graves were found to contain no human remains or

grave goods Grave goods, in archaeology and anthropology, are the items buried along with the body. They are usually personal possessions, supplies to smooth the deceased's journey into the afterlife or offerings to the gods. Grave goods may be classed as a ...

, and it has been hypothesized that they were in reality the incubation mounds of ''Sylviornis''. As these mounds are up to high and wide even after nearly four millennia, they seem too large to have been made by the giant scrubfowl (''Megapodius molistructor''), an extinct New Caledonian species of megapode.

However, recent assessment of this bird as outside and not even particularly closely related to megapodes make the possibility that it was a mound-builder like them strictly unlikely.

Ecology

Little can be said about the lifestyle of ''Sylviornis''. It was probably a slow-moving browser, and the structure of the bill and feet suggest that roots and tubers it dug up formed a major part of its diet.

Extinction

The bird was hunted to extinction by the Lapita ancestors of the

Kanak people The Kanak (French language, French spelling until 1984: Canaque) are the Indigenous peoples of Oceania, indigenous Melanesians, Melanesian inhabitants of New Caledonia, an overseas collectivity of France in the southwest Pacific Ocean, Pacifi ...

, who settled New Caledonia around 1500 BC. Predation by feral dogs and pigs probably also played a part. The legacy of ''Sylviornis'' persists in Kanak oral history in the form of stories giving a rough description of the bird and some of its habits.

References

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External links