The Gruiformes are an order containing a considerable number of living and extinct bird families, with a widespread geographical diversity. Gruiform means "crane-like".
Phorusrhacids, colloquially known as terror birds, are an extinct family of large carnivorous, mostly flightless birds that were among the largest apex predators in South America during the Cenozoic era. Their definitive fossil records range from the Middle Eocene to the Late Pleistocene around 43 to 0.1 million years ago, though some specimens suggest that they were present since the Early Eocene.
Phorusrhacos is an extinct genus of giant flightless terror birds that inhabited South America during the Miocene epoch. Phorusrhacos was one of the dominant land predators in South America at the time it existed. It is thought to have lived in woodlands and grasslands.
Andalgalornis is a genus of flightless predatory birds of the extinct family Phorusrhacidae that lived in Argentina. The type and only species is A. steulleti.
Brontornis is an extinct genus of giant bird that inhabited Argentina during the Early to Middle Miocene. Its taxonomic position is highly controversial, with authors alternatively considering it to be a cariamiform, typically a phorusrhacid or an anserimorph.
Strigogyps is an extinct genus of prehistoric bird from the Middle Eocene to Early Oligocene of France and Germany. It was probably around the size of a large chicken or a guan, weighing not quite 1 kilogram (2.2 lb). Apparently, as indicated by the ratio of lengths of wing to leg bones, S. sapea was flightless. Its legs were not adapted to running, so it seems to have had a walking lifestyle similar to trumpeters. Unlike other Cariamiformes which appear to have been mostly carnivorous, the specimens of one species, Strigogyps sapea, suggest a facultatively herbivorous or omnivorous diet.
The Sophiornithidae are an extinct family of chicken-sized predatory birds that lived from the Paleocene to the Eocene periods of the Cenozoic, and were found primarily in Europe, and are thought to be primitive owls.
The red-legged seriema, also known as the crested cariama and crested seriema, is a mostly predatory terrestrial bird in the seriema family (Cariamidae), included in the Gruiformes in the old paraphyletic circumscription but recently placed in a distinct order: Cariamiformes.
The black-legged seriema is one of two living species of seriemas in the family Cariamidae. It is found from southeastern Bolivia and northern Paraguay south into north-central Argentina. It is a large, mostly grey bird with a long neck, a long tail, and long, slender black legs. Its belly, vent and thighs are yellowish-white. The sexes look similar, as do immature birds, though the latter are more patterned on head, neck and back. First described for science by Gustav Hartlaub in 1860, it is monotypic, with no subspecies. Like its red-legged cousin, it is an omnivore. It seldom flies, instead pursuing prey and eluding danger on foot. Its loud calls, said to sound like kookaburras, turkeys or yelping dogs, are often given in duet. Little is known about its breeding ecology. It is known to breed in November and December, building a platform nest of sticks and laying two white eggs, which are sometimes marked with a few brownish or purple spots. The International Union for Conservation of Nature rates the species as one of least concern, due to its large range and apparently stable numbers.
Paraphysornis is an extinct genus of giant flightless terror birds that inhabited Brazil during Late Oligocene or Early Miocene epochs. Although not the tallest phorusrhacid, Paraphysornis measured up to 1.4 metres tall at the hips and weighed around 180–240 kilograms (400–530 lb). It was also a notably robust bird, having short and robust tarsal bones not suited for pursuit hunting.
Patagornis is a genus of extinct flightless predatory birds of the family Phorusrhacidae. Known as "terror birds", these lived in what is now Argentina during the Early and Middle Miocene; the Santa Cruz Formation in Patagonia contains numerous specimens. Patagornis was an agile, medium sized Patagornithine and was likely a pursuit predator.
Procariama is an extinct monotypic genus of phorusrhacid, which lived from the Late Miocene to the Late Pliocene of Argentina. Fossils of the animal have been found in six places, in the Cerro Azul and Andalhuala Formations. More specifically in the Andagalá department and in the north of the Belén department of the Catamarca province, with a single location in the La Pampa province. The type and only species, Procariama simplex, is the largest member of the subfamily Psilopterinae.
Psilopterus is an extinct genus of phorusrhacid from the Middle Oligocene to possibly the Late Pleistocene of Argentina and Uruguay. Compared to other phorusrhacids, members of the genus are both relatively gracile and diminutive, and include the smallest known species of terror bird: with the head raised P. bachmanni was 70–80 centimeters (2.3–2.6 ft) in height and weighed about 5 kilograms (11 lb), while the largest members of the genus were only about 8 kilograms (18 lb). The birds resemble the modern cariama, except with a heavier build and considerably smaller wings. Fossil finds in Uruguay indicate the genus may have survived until 96,040 ± 6,300 years ago, millions of years after the larger phorusrhacids became extinct.
Cariamiformes is an order of primarily flightless birds that has existed for over 50 million years. The group includes the family Cariamidae (seriemas) and the extinct families such as Phorusrhacidae, Bathornithidae, Idiornithidae and Ameghinornithidae. Extant members (seriemas) are only known from South America, but fossils of many extinct taxa are also found in other continents including Europe and North America. Though traditionally considered a suborder within Gruiformes, both morphological and genetic studies show that it belongs to a separate group of birds, Australaves, whose other living members are Falconidae, Psittaciformes and Passeriformes.
Chunga is one of two known genera of seriemas in the family Cariamidae. It is found in Argentina, Bolivia, and Paraguay. It contains one living species, the black-legged seriema. A prehistoric species, Chunga incerta, has been described from the Miocene and Pliocene Monte Hermoso Formation of Argentina.
Bathornithidae is an extinct family of birds from the Eocene to Miocene of North America. Part of Cariamiformes, they are related to the still extant seriemas and the extinct Phorusrhacidae. They were likely similar in habits, being terrestrial, long-legged predators, some of which attained massive sizes.
Paracrax is a genus of extinct North American flightless birds, possibly related to modern seriemas and the extinct terror birds. Part of Bathornithidae, it is a specialised member of this group, being cursorial carnivores much like their South American cousins, some species attaining massive sizes.
Bathornis is an extinct lineage of birds related to modern day seriemas, that lived in North America about 37–20 million years ago. Like the closely related and also extinct phorusrhacids, it was a flightless predator, occupying predatory niches in environments classically considered to be dominated by mammals. It was a highly diverse and successful genus, spanning a large number of species that occurred from the Priabonian Eocene to the Burdigalian Miocene epochs.
Elaphrocnemus is a genus of extinct bird from the Eocene and Oligocene periods of Europe. Part of Cariamiformes, its closest living relatives are seriemas, though it differs significantly from them, being a better flyer.
Chunga incerta is an extinct species of cariamid bird which inhabited the Pliocene of the central-eastern Southern Cone of South America. It belongs to the genus Chunga, today only represented by one species, Chunga burmeisteri.
