Leg bone fragment from Flores cave described as new megapode species

A fossil megapode, a ground-dwelling relative of the chicken, has been described as a new species from one fragment of leg bone found in the Liang Bua cave on the Indonesian island of Flores. Named Megapodius rokusi, the bird weighed approximately 3.9 kg, according to the authors of the study. The only megapode living on Flores today, the orange-footed megapode (Megapodius reinwardt), weighs between 0.5 and 1.2 kg.

The description rests on the lower half of a right tarsometatarsus, a lower leg bone, excavated in 2009 at Liang Bua. That is the cave where the small-bodied human relative Homo floresiensis was found. The bone came from sediments dated to roughly 190,000 to 120,000 years ago. It is larger than the same bone in any known living or extinct species of Megapodius, and the species is the first fossil megapode described from Wallacea, the island region between mainland Asia and Australia.

Megapodes, also called incubator birds or mound-builders, are medium-sized to large terrestrial birds with large legs and feet with sharp claws. "Megapodes are a group of birds that incubate their eggs by burying them, exploiting environmental heat rather than body heat," said University Museum of Bergen paleontologist Hanneke Meijer and colleagues. They wrote that the birds are almost entirely limited to the region east of Wallace's line, in the Philippines, eastern Indonesia, Melanesia and Australia, and that they do not occur in mainland Southeast Asia or on the Greater Sunda Islands. The authors note that this distribution has been attributed to an ancient relic distribution, the introduction or domestication of Megapodius on western islands, competition between megapodes and phasianids, and bird-eating mammalian carnivores on the Asian mainland and the Greater Sundas.

The species name honors the Indonesian zooarchaeologist Rokus Due Awe. The researchers said he played a seminal role in analyzing faunal remains and was the first person to correctly identify the hominin bones and teeth that became part of the hypodigm of Homo floresiensis after the discovery of the famous partial skeleton in 2003. They described Megapodius rokusi as the first species of megapode named after an Indonesian researcher.

The authors also point to the bird's possible role as food. "Megapode eggs have a yolk that makes up about 50-60% of the egg weight and are considered very nutritious," they said. They added that the distinct mounds and communal burrowing grounds make megapode eggs and chicks highly susceptible to predation. In their words, the eggs "would have been an accessible source of nutrients for both Homo floresiensis and modern humans before and after 50,000 years ago, respectively."

No shoulder or wing bones were recovered, so the scientists cannot tell whether the bird could fly. They also do not know when it went extinct or whether it lived alongside the smaller species still found on Flores. They raise the possibility that the living species reached the island only after the larger bird had disappeared.

The study, by Hanneke J. M. Meijer and colleagues, was published online on October 22, 2026, in Alcheringa, an Australasian Journal of Palaeontology. Its DOI is 10.1080/03115518.2026.2741158.