It is considered to constitute one of two genera in the extinct family Sylviornithidae, alongside Megavitiornis from Fiji, which are related to the Galliformes, the group containing the turkeys, chickens, quails and pheasants.

[2] 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.

[citation needed] Native accounts believed to be based on Sylviornis describe a bird reddish in color, with a star-shaped calque on its head, and fast despite being flightless because it used its reduced wings for balance while running.

[4] The anatomy of its skull suggests that it had a reduced optic lobes, with a well developed sense of smell and somatosensorial system, adapted for being active during twilight conditions (crepuscular) in search of food.

Because of its beak morphology and chicken-like feet, some authors guessed that the species was a herbivore that fed on low vegetation and dug up roots and tubers, but others that it was a specialized invertebrate predator.