The island of New Caledonia once was home to a number of both ancient and strange birds, with one of them standing practically head and shoulders above the rest. This rather odd bird was the so-called New Caledonian giant fowl, Sylviornis neocaledoniae. The animal’s common name comes from the fact that it might have been a type of bird called a megapode, a distant relative of chickens and pheasants, a well-known group spread all over the globe. This whole family of birds is known as the Galliformes and Sylviornis itself was a unique creature. Its subfossil remains were described by Francois Poplin in 1980. For a while the bird was incredibly hard to classify. At first it was thought to have been related to ostriches and emus. That is, until recently.
A new study by Trevor H. Worthy, Miyess Mitri, Atholl Anderson and colleagues allowed for a new conclusion. After an analysis of the 600 or so subfossil remains of the bird, some of which are more than 5000 years old, it was realized just what kind of bird Sylviornis was. It was not a real megapode as its name suggested, instead being a sort of primitive stem-Galliforme. Thus it lay at the very base of this huge bird family.
The reasoning behind its former classification as a megapode comes from supposed mounds that might have been made by these huge birds. After all, mound nests are a megapode trademark, so it might be reasonable to suggest that Sylviornis was building mounds too. Yet its new position in the family makes mound-building a highly unlikely act. Instead of building mounds, it was probably more adept at digging and scratching the ground in search of the roots, seeds and tubers that made up part of its diet along with the leaves of low-growing shrubs. It certainly had the foot anatomy for digging and rooting, according to the new study by Worthy. So while it was not a true “giant chicken,” Sylviornis was still part of Galliformes, so this is about as close as one will get.