Sylviornithidae is an extinct family of

flightless birds Flightless birds are birds that cannot Bird flight, fly, as they have, through evolution, lost the ability to. There are over 60 extant species, including the well-known ratites (ostriches, emus, cassowary, cassowaries, Rhea (bird), rheas, an ...

, known from

subfossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

bones found in

Holocene The Holocene () is the current geologic time scale, geological epoch, beginning approximately 11,700 years ago. It follows the Last Glacial Period, which concluded with the Holocene glacial retreat. The Holocene and the preceding Pleistocene to ...

aged deposits on the Melanesian islands of

New Caledonia New Caledonia ( ; ) is a group of islands in the southwest Pacific Ocean, southwest of Vanuatu and east of Australia. Located from Metropolitan France, it forms a Overseas France#Sui generis collectivity, ''sui generis'' collectivity of t ...

and

Fiji Fiji, officially the Republic of Fiji, is an island country in Melanesia, part of Oceania in the South Pacific Ocean. It lies about north-northeast of New Zealand. Fiji consists of an archipelago of more than 330 islands—of which about ...

. For many years it was considered a

monotypic In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unisp ...

family consisting of the New Calendonia ''

Sylviornis ''Sylviornis'' is an extinct genus 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 Sylviornithidae, alongside '' Megaviti ...

'' alone, but recent studies show that the Fijian ''

Megavitiornis ''Megavitiornis altirostris'' is an extinct, flightless, giant stem-galliform bird that was endemic to Fiji, it is the only known species in the genus ''Megavitiornis''. Originally thought to be a megapode, more recent morphological studies indic ...

'' was part of this

clade In biology, a clade (), also known as a Monophyly, monophyletic group or natural group, is a group of organisms that is composed of a common ancestor and all of its descendants. Clades are the fundamental unit of cladistics, a modern approach t ...

as well. Long considered to have

galliform Galliformes is an order (biology), order of heavy-bodied ground-feeding birds that includes turkey (bird), turkeys, chickens, Old World quail, quail, and other landfowl. Gallinaceous birds, as they are called, are important in their ecosystems ...

affinities, a 2016 study suggested that they were outside the Galliformes

crown group In phylogenetics, the crown group or crown assemblage is a collection of species composed of the living representatives of the collection, the most recent common ancestor of the collection, and all descendants of the most recent common ancestor ...

,Worthy, T., Mitri, M., Handley, W., Lee, M., Anderson, A., Sand, C. 2016. Osteology supports a steam-galliform affinity for the giant extinct flightless birds Sylviornis neocaledoniae (Sylviornithidae, Galloanseres). PLOS ONE. doi: 10.1371/journal.pone.0150871 while a 2024 study suggested that they were members of the Galliformes crown group as more closely related to

Phasianoidea Phasianoidea is a superfamily of birds of the order of the Galliformes. Taxonomy Description The superfamily was described in 1825 by the Irish zoologist Nicholas Aylward Vigors.Vigors, N. A. (1825): "Observations on the Natural Affinities ...

than to

Megapodiidae The megapodes, also known as incubator birds or mound-builders, are stocky, medium-large, chicken-like birds with small heads and large feet in the family Megapodiidae. Their name literally means "large foot" and is a reference to the heavy leg ...

, and were most closely related to the extinct giant gastornithids.

References

{{Taxonbar, from=Q19789329 Extinct flightless birds Late Quaternary prehistoric birds New Caledonia Holocene fauna Holocene extinctions Prehistoric bird families Galloanserae Taxa named by Cécile Mourer-Chauviré Taxa named by Jean-Christophe Balouet