Magpie Goose - Systematics and Evolution

Systematics and Evolution

This species is placed in the order Anseriformes, having the characteristic bill structure, but is considered to be distinct from the other species in this taxon. The related and extant families, Anhimidae (screamers) and Anatidae (ducks, geese and swans), contain all the other taxa. The Magpie Goose is contained in the genus Anseranas and family Anseranatidae, which are monotypic in our age.

A cladistic study of the morphology of waterfowl found that the Magpie Goose was an early and distinctive offshoot, diverging after screamers and before all other ducks, geese and swans.

This family is quite old, a living fossil, having apparently diverged before the Cretaceous–Paleogene extinction event — the relative Vegavis iaai lived some 68-67 million years ago. The fossil record is limited, nonetheless. The enigmatic genus Anatalavis (Hornerstown Late Cretaceous or Early Paleocene of New Jersey, USA - London Clay Early Eocene of Walton-on-the-Naze, England) is sometimes considered to be the earliest known anseranatid. Other Paleogene birds sometimes considered magpie-geese are the genera Geranopsis from the Hordwell Formation Late Eocene to the Early Oligocene of England and Anserpica from the Late Oligocene of Billy-Créchy (France). The earliest known member of the group in Australia is an unnamed species represented by fossils found in the late Oligocene Carl Creek Limestone of Queensland. Additional fossils from North America and Europe suggest that the family was spread across the globe during the late Paleogene period. The Australian distribution of the living species ties in well with the presumed Gondwanan origin of Anseriformes, but Northern Hemisphere fossils are puzzling. Perhaps the magpie-geese were one of the dominant groups of Paleogene waterfowl, only to become largely extinct later.