A ratite is any of a group of mostly flightless birds within the infraclass Palaeognathae. They are mostly large, long-necked, and long-legged, the exception being the kiwi, which is also the only nocturnal extant ratite.
Struthionidae is a family of flightless birds, containing the extant ostriches and their extinct relatives. The two extant species of ostrich are the common ostrich and Somali ostrich, both in the genus Struthio, which also contains several species known from Holocene fossils such as the Asian ostrich. The common ostrich is the more widespread of the two living species, and is the largest living bird species. The extinct genus Pachystruthio from the Late Pliocene-Early Pleistocene of Eurasia is one of the largest birds ever.
Genyornis newtoni, also known as the Newton's mihirung, Newton's thunder bird or mihirung paringmal, is an extinct species of large, flightless bird that lived in Australia during the Pleistocene Epoch until around 50,000 years ago. Over two metres in height, they were likely herbivorous. Many other species of Australian megafauna became extinct in Australia around that time, coinciding with the arrival of humans. It is the last known member of the extinct flightless bird family Dromornithidae which had been part of the fauna of the Australian continent for over 30 million years. They are not closely related to ratites such as emus, and their closest living relatives are thought to be fowl.
Elephant birds are extinct flightless birds belonging to the order Aepyornithiformes that were native to the island of Madagascar. They are thought to have become extinct around 1000 AD, likely as a result of human activity. Elephant birds comprised three species, one in the genus Mullerornis, and two in Aepyornis.Aepyornis maximus is possibly the largest bird to have ever lived, with their eggs being the largest known for any amniote. Elephant birds are palaeognaths, and their closest living relatives are kiwi, suggesting that ratites did not diversify by vicariance during the breakup of Gondwana but instead convergently evolved flightlessness from ancestors that dispersed more recently by flying.
Gastornis is an extinct genus of large, flightless birds that lived during the mid-Paleocene to mid-Eocene epochs of the Paleogene period. Fossils have been found in Europe, Asia and North America, with the North American specimens formerly assigned to the genus Diatryma.
Ostriches are large flightless birds. They are the heaviest and largest living birds, with adult common ostriches weighing anywhere between 63.5 and 145 kilograms and laying the largest eggs of any living land animal. With the ability to run at 70 km/h (43.5 mph), they are the fastest birds on land. They are farmed worldwide, with significant industries in the Philippines and in Namibia. South Africa produces about 70% of global ostrich products, with the industry largely centered around the town of Oudtshoorn. Ostrich leather is a lucrative commodity, and the large feathers are used as plumes for the decoration of ceremonial headgear. Ostrich eggs have been used by humans for millennia.
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 conventionally accepted temporal range covers from 53 to 0.1 million years (Ma) ago, and perhaps even up to 21,600 ± 1,000 years ago.
Dromornithidae, known as mihirungs and informally as thunder birds or demon ducks, were a clade of large, flightless Australian birds of the Oligocene through Pleistocene Epochs. All are now extinct. They were long classified in Struthioniformes, but are now usually classified as galloanseres. Dromornithids were part of the Australian megafauna. One species, Dromornis stirtoni, was 3 m tall. Only a single species, Genyornis newtoni survived into the Late Pleistocene. They are thought to have been herbivorous.
Dromornis is a genus of large to enormous prehistoric birds native to Australia during the Oligocene to Pliocene epochs. The species were flightless, possessing greatly reduced wing structures but with large legs, similar to the modern ostrich or emu. They were likely to have been predominantly, if not exclusively, herbivorous browsers. The male of the largest species, Dromornis stirtoni, is a contender for the tallest and heaviest bird, and possibly exhibited aggressive territorial behaviour. They belong to the family Dromornithidae, extinct flightless birds known as mihirungs.
Palaeognathae is an infraclass of birds, called paleognaths or palaeognaths, within the class Aves of the clade Archosauria. It is one of the two extant infraclasses of birds, the other being Neognathae, both of which form Neornithes. Palaeognathae contains five extant branches of flightless lineages, termed ratites, and one flying lineage, the Neotropic tinamous. There are 47 species of tinamous, five of kiwis (Apteryx), three of cassowaries (Casuarius), one of emus (Dromaius), two of rheas (Rhea) and two of ostriches (Struthio). Recent research has indicated that paleognaths are monophyletic but the traditional taxonomic split between flightless and flighted forms is incorrect; tinamous are within the ratite radiation, meaning flightlessness arose independently multiple times via parallel evolution.
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.
Palaeotis is a genus of paleognath birds from the middle Eocene epoch of central Europe. One species is known, Palaeotis weigelti. The holotype specimen is a fossil tarsometatarsus and phalanx. Lambrect (1928) described it as an extinct bustard, and gave it its consequent name. After a suggestion by Storrs L. Olson, a review of the type specimen and the referral of several other fossils by Houde and Haubold (1987) concluded that Palaeotis is a palaeognath and assigned it to the same order as ostriches; the Struthioniformes. In 2021, it was considered a member of the family Paleotididae alongside Galligeranoides from the Early Eocene of France, which were found to be basal members of the Struthioniformes.
The Asian or Asiatic ostrich, is an extinct species of ostrich that lived during the Neogene period on the Indian subcontinent.
Gargantuavis is an extinct genus of large, primitive bird containing the single species Gargantuavis philoinos. It is the only member of the monotypic family Gargantuaviidae. Its fossils were discovered in several formations dating to 73.5 and 71.5 million years ago in what is now northern Spain, southern France, and Romania. Gargantuavis is the largest known bird of the Mesozoic, a size ranging between the cassowary and the ostrich, and a mass of 141 kg (311 lb) like modern ostriches, exemplifying the extinction of non-avian dinosaurs was not a necessary condition for the emergence of giant terrestrial birds. It was once thought to be closely related to modern birds, but the 2019 discovery of a pelvis from what was Hateg Island shows several primitive features.
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.
The largest prehistoric animals include both vertebrate and invertebrate species. Many of them are described below, along with their typical range of size. Many species mentioned might not actually be the largest representative of their clade due to the incompleteness of the fossil record and many of the sizes given are merely estimates since no complete specimen have been found. Their body mass, especially, is largely conjecture because soft tissue was rarely fossilized. Generally the size of extinct species was subject to energetic and biomechanical constraints.
Leptoptilos robustus is an extinct species of large-bodied stork belonging to the genus Leptoptilos that lived on the island of Flores in Indonesia during the Pleistocene epoch. It stood at about 1.8 metres (5.9 ft) tall and weighed up to an estimated 16 kilograms (35 lb). The majority of the discoveries are concentrated in Liang Bua cave located slightly north of Ruteng in the East Nusa Tenggara province.
Struthio anderssoni, also known as the East Asian ostrich, is an extinct species of ostrich that lived in the Pleistocene and Holocene in China and Mongolia. In 2023, based on a re-examination of cast of a femur, it was suggested that this species be moved the genus Pachystruthio.
Pterocles bosporanus is an extinct species of sandgrouse, described in 2023 from early Pleistocene-aged fossil material found in central Crimea. Potential additional remains are known from Italy. The only confirmed specimen is part of a limb bone, and the species is larger than other members of the genus Pterocles.
