Anseranatidae
Encyclopedia
Anseranatidae, the magpie-geese, is a biological family of waterbirds. It is a unique member of the order
Anseriformes
. The only living species, the Magpie Goose, is a resident breeder in northern Australia
and in southern New Guinea
.
Anseriformes
, having the characteristic bill structure, but is considered to be distinct from the other families in this taxon
. The related and extant families, Anhimidae (screamer
s) and Anatidae
(duck
s, geese
and swan
s), contain all the other taxa.
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 mass extinction - 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.
Order (biology)
In scientific classification used in biology, the order is# a taxonomic rank used in the classification of organisms. Other well-known ranks are life, domain, kingdom, phylum, class, family, genus, and species, with order fitting in between class and family...
Anseriformes
Anseriformes
The order Anseriformes contains about 150 living species of birds in three extant families: the Anhimidae , Anseranatidae , and the Anatidae, which includes over 140 species of waterfowl, among them the ducks, geese, and swans.All species in the order are highly adapted for an aquatic existence at...
. The only living species, the Magpie Goose, is a resident breeder in northern Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
and in southern New Guinea
New Guinea
New Guinea is the world's second largest island, after Greenland, covering a land area of 786,000 km2. Located in the southwest Pacific Ocean, it lies geographically to the east of the Malay Archipelago, with which it is sometimes included as part of a greater Indo-Australian Archipelago...
.
Systematics and evolution
This family is placed in the orderOrder (biology)
In scientific classification used in biology, the order is# a taxonomic rank used in the classification of organisms. Other well-known ranks are life, domain, kingdom, phylum, class, family, genus, and species, with order fitting in between class and family...
Anseriformes
Anseriformes
The order Anseriformes contains about 150 living species of birds in three extant families: the Anhimidae , Anseranatidae , and the Anatidae, which includes over 140 species of waterfowl, among them the ducks, geese, and swans.All species in the order are highly adapted for an aquatic existence at...
, having the characteristic bill structure, but is considered to be distinct from the other families in this taxon
Taxon
|thumb|270px|[[African elephants]] form a widely-accepted taxon, the [[genus]] LoxodontaA taxon is a group of organisms, which a taxonomist adjudges to be a unit. Usually a taxon is given a name and a rank, although neither is a requirement...
. The related and extant families, Anhimidae (screamer
Screamer
The screamers are a small family of birds, the Anhimidae. For a long time they were thought to be related to the Galliformes because of similar bills, but they are truly related to ducks , most closely to the Magpie Goose...
s) and Anatidae
Anatidae
Anatidae is the biological family of birds that includes ducks, geese and swans. The family has a cosmopolitan distribution, occurring on all the world's continents except Antarctica and on most of the world's islands and island groups...
(duck
Duck
Duck is the common name for a large number of species in the Anatidae family of birds, which also includes swans and geese. The ducks are divided among several subfamilies in the Anatidae family; they do not represent a monophyletic group but a form taxon, since swans and geese are not considered...
s, geese
Goose
The word goose is the English name for a group of waterfowl, belonging to the family Anatidae. This family also includes swans, most of which are larger than true geese, and ducks, which are smaller....
and swan
Swan
Swans, genus Cygnus, are birds of the family Anatidae, which also includes geese and ducks. Swans are grouped with the closely related geese in the subfamily Anserinae where they form the tribe Cygnini. Sometimes, they are considered a distinct subfamily, Cygninae...
s), contain all the other taxa.
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
Living fossil
Living fossil is an informal term for any living species which appears similar to a species otherwise only known from fossils and which has no close living relatives, or a group of organisms which have long fossil records...
, having apparently diverged before the Cretaceous–Paleogene mass extinction - the relative Vegavis iaai lived some 68-67 million years ago. The fossil
Fossil
Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...
record is limited, nonetheless. The enigmatic genus Anatalavis
Anatalavis
Anatalavis is genus of prehistoric birds related to ducks and geese, perhaps in particular the Magpie-goose. The species Anatalavis rex - formerly placed in Telmatornis - is known from the Hornerstown Formation of New Jersey...
(Hornerstown
Hornerstown Formation
The Hornerstown Formation is a Paleogene or latest Mesozoic geologic formation. The age of these deposits have been controversial. While most fossils are of animals types known from the earliest Cenozoic era, several fossils of otherwise exclusively Cretaceous age have been found...
Late Cretaceous
Late Cretaceous
The Late Cretaceous is the younger of two epochs into which the Cretaceous period is divided in the geologic timescale. Rock strata from this epoch form the Upper Cretaceous series...
or Early Paleocene of New Jersey, USA - London Clay
London Clay
The London Clay Formation is a marine geological formation of Ypresian age which crops out in the southeast of England. The London Clay is well known for the fossils it contains. The fossils from the Lower Eocene indicate a moderately warm climate, the flora being tropical or subtropical...
Early Eocene of Walton-on-the-Naze
Walton-on-the-Naze
Walton-on-the-Naze is a small town in Essex, England, on the North Sea coast in the Tendring district. It is north of Clacton and south of the port of Harwich. It abuts Frinton-on-Sea to the south, and is part of the parish of Frinton and Walton. It is a resort town, with a permanent population of...
, England) is sometimes considered to be the earliest known anseranatid. Other Paleogene
Paleogene
The Paleogene is a geologic period and system that began 65.5 ± 0.3 and ended 23.03 ± 0.05 million years ago and comprises the first part of the Cenozoic Era...
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
Billy, Allier
Billy is a commune in the Allier department in central France.Between this village and nearby Créchy, lagerstätten have yielded a rich assemblage of fossils from the Oligocene-Miocene boundary .-Population:...
-Créchy
Créchy
Créchy is a commune in the Allier department in central France.Between this village and nearby Billy, lagerstätten have yielded a rich assemblage of fossils from the Oligocene-Miocene boundary Créchy is a commune in the Allier department in central France.Between this village and nearby Billy,...
(France
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...
). The earliest known member of the group in Australia is an unnamed species represented by fossils found in the late Oligocene
Oligocene
The Oligocene is a geologic epoch of the Paleogene Period and extends from about 34 million to 23 million years before the present . As with other older geologic periods, the rock beds that define the period are well identified but the exact dates of the start and end of the period are slightly...
Carl Creek Limestone of Queensland
Queensland
Queensland is a state of Australia, occupying the north-eastern section of the mainland continent. It is bordered by the Northern Territory, South Australia and New South Wales to the west, south-west and south respectively. To the east, Queensland is bordered by the Coral Sea and Pacific Ocean...
. Additional fossils from North America and Europe suggest that the family was spread across the globe during the late Paleogene
Paleogene
The Paleogene is a geologic period and system that began 65.5 ± 0.3 and ended 23.03 ± 0.05 million years ago and comprises the first part of the Cenozoic Era...
period.