Sylviornis
Encyclopedia
Sylviornis is an extinct genus of galliform
bird containing a single species, S. neocaledoniae, or erroneously, "New Caledonian Giant Megapode". Technically, the latter is incorrect because it has recently been found not to be a megapode, but the sole known member of its own family
, the Sylviornithidae; at the time of its description, it was believed to be a ratite
. Sylviornis was never encountered alive by scientists, but it is known from many thousands of subfossil
bones found in deposits, some of them from the Holocene
, on New Caledonia
and the adjacent Île des Pins
.
Sylviornis was a huge, flightless bird, 1.70 meters long altogether, and weighing around 30 kg. 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
s were not fused to a furcula
, the number of caudal vertebrae was very high, and the ribcage and pelvis were almost dinosaur
ian in appearance. The wings were reduced to small stubs.
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. Apparently, 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
, and it has been hypothesized that they were in reality the incubation mounds of Sylviornis. As these mounds are up to 5 m high and 50 m wide even after nearly 4 millennia, they seem too large to have been made by the Giant Scrubfowl
, an extinct New Caledonian species of megapode.
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.
ancestors of the Kanak people, 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. A native name was du.
Galliformes
Galliformes are an order of heavy-bodied ground-feeding domestic or game bird, containing turkey, grouse, chicken, New and Old World Quail, ptarmigan, partridge, pheasant, and the Cracidae. Common names are gamefowl or gamebirds, landfowl, gallinaceous birds or galliforms...
bird containing a single species, S. neocaledoniae, or erroneously, "New Caledonian Giant Megapode". Technically, the latter is incorrect because it has recently been found not to be a megapode, but the sole known member of its own family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
, the Sylviornithidae; at the time of its description, it was believed to be a ratite
Ratite
A ratite is any of a diverse group of large, flightless birds of Gondwanan origin, most of them now extinct. Unlike other flightless birds, the ratites have no keel on their sternum—hence the name from the Latin ratis...
. Sylviornis was never encountered alive by scientists, but it is known from many thousands of subfossil
Subfossil
Subfossil refers to remains whose fossilization process is not complete, either for lack of time or because the conditions in which they were buried were not optimal for fossilization....
bones found in deposits, some of them from the Holocene
Holocene
The Holocene is a geological epoch which began at the end of the Pleistocene and continues to the present. The Holocene is part of the Quaternary period. Its name comes from the Greek words and , meaning "entirely recent"...
, on New Caledonia
New Caledonia
New Caledonia is a special collectivity of France located in the southwest Pacific Ocean, east of Australia and about from Metropolitan France. The archipelago, part of the Melanesia subregion, includes the main island of Grande Terre, the Loyalty Islands, the Belep archipelago, the Isle of...
and the adjacent Île des Pins
Isle of Pines, New Caledonia
The Isle of Pines is an island located in the Pacific Ocean, in the archipelago of New Caledonia, an overseas territory of France. The island is part of the commune of L'Île-des-Pins, in the South Province of New Caledonia. The Isle of Pines is nicknamed l'île la plus proche du paradis...
.
Sylviornis was a huge, flightless bird, 1.70 meters long altogether, and weighing around 30 kg. 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
Clavicle
In human anatomy, the clavicle or collar bone is a long bone of short length that serves as a strut between the scapula and the sternum. It is the only long bone in body that lies horizontally...
s were not fused to a furcula
Furcula
The ' is a forked bone found in birds, formed by the fusion of the two clavicles. In birds, its function is the strengthening of the thoracic skeleton to withstand the rigors of flight....
, the number of caudal vertebrae was very high, and the ribcage and pelvis were almost dinosaur
Dinosaur
Dinosaurs are a diverse group of animals of the clade and superorder Dinosauria. They were the dominant terrestrial vertebrates for over 160 million years, from the late Triassic period until the end of the Cretaceous , when the Cretaceous–Paleogene extinction event led to the extinction of...
ian in appearance. The wings were reduced to small stubs.
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. Apparently, 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
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 are a type of votive deposit...
, and it has been hypothesized that they were in reality the incubation mounds of Sylviornis. As these mounds are up to 5 m high and 50 m wide even after nearly 4 millennia, they seem too large to have been made by the Giant Scrubfowl
Pile-builder Megapode
The Pile-builder Megapode is an extinct species of megapode. The fossil remains were found by Jean-Christophe Balouet and Storrs L. Olson in caves on New Caledonia and Tonga.-Description:...
, an extinct New Caledonian species of megapode.
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 LapitaLapita
Lapita is a term applied to an ancient Pacific Ocean archaeological culture which is believed by many archaeologists to be the common ancestor of several cultures in Polynesia, Micronesia, and some coastal areas of Melanesia...
ancestors of the Kanak people, 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
Oral history
Oral history is the collection and study of historical information about individuals, families, important events, or everyday life using audiotapes, videotapes, or transcriptions of planned interviews...
in the form of stories giving a rough description of the bird and some of its habits. A native name was du.
See also
- Late Quaternary prehistoric birdsLate Quaternary prehistoric birdsPrehistoric birds are various taxa of birds that became extinct before recorded history, or more precisely, before they could be studied alive by bird scientists...
- Island gigantismIsland gigantismIsland gigantism or insular giantism is a biological phenomenon in which the size of animals isolated on an island increases dramatically in comparison to their mainland relatives....
- Biodiversity of New CaledoniaBiodiversity of New CaledoniaThe Biodiversity of New Caledonia is considered to be one of the most important in the world. New Caledonia, a large south Pacific island group about 1,200 km east of Australia, supports high levels of endemism, with many unique plants, insects, reptiles and birds...
- Holocene extinction