Frigatebirds are a family of seabirds called Fregatidae which are found across all tropical and subtropical oceans. The five extant species are classified in a single genus, Fregata. All have predominantly black plumage, long, deeply forked tails and long hooked bills. Females have white underbellies and males have a distinctive red gular pouch, which they inflate during the breeding season to attract females. Their wings are long and pointed and can span up to 2.3 metres (7.5 ft), the largest wing area to body weight ratio of any bird.
The family Threskiornithidae includes 36 species of large wading birds. The family has been traditionally classified into two subfamilies, the ibises and the spoonbills; however recent genetic studies have cast doubt on this arrangement, and have found the spoonbills to be nested within the Old World ibises, and the New World ibises as an early offshoot.
The bird family Sulidae comprises the gannets and boobies. Collectively called sulids, they are medium-large coastal seabirds that plunge-dive for fish and similar prey. The 10 species in this family are often considered congeneric in older sources, placing all in the genus Sula. However, Sula and Morus (gannets) can be readily distinguished by morphological, behavioral, and DNA sequence characters. Abbott's booby (Papasula) is given its own genus, as it stands apart from both in these respects. It appears to be a distinct and ancient lineage, maybe closer to the gannets than to the true boobies.
Plotopteridae is an extinct family of flightless seabirds with uncertain placement, generally considered as member of order Suliformes. They exhibited remarkable convergent evolution with the penguins, particularly with the now extinct giant penguins. That they lived in the North Pacific, the other side of the world from the penguins, has led to them being described at times as the Northern Hemisphere's penguins, though they were not closely related. More recent studies have shown, however, that the shoulder-girdle, forelimb and sternum of plotopterids differ significantly from those of penguins, so comparisons in terms of function may not be entirely accurate. Plotopterids are regarded as closely related to Anhingidae (darters) and Phalacrocoracidae (cormorants). On the other hand, there is a theory that this group may have a common ancestor with penguins due to the similarity of forelimb and brain morphology. However, the endocast morphology of stem group Sphenisciformes differs from both Plotopteridae and modern penguins.
The lesser frigatebird is a seabird of the frigatebird family Fregatidae. At around 75 cm (30 in) in length, it is the smallest species of frigatebird. It occurs over tropical and subtropical waters across the Indian and Pacific Oceans as well as off the Atlantic coast of Brazil.
The Pelagornithidae, commonly called pelagornithids, pseudodontorns, bony-toothed birds, false-toothed birds or pseudotooth birds, are a prehistoric family of large seabirds. Their fossil remains have been found all over the world in rocks dating between the Early Paleocene and the Pliocene-Pleistocene boundary.
Copepteryx is an extinct genus of flightless bird of the family Plotopteridae, endemic to Japan during the Oligocene living from 28.4 to 23 mya, meaning it existed for approximately 5.4 million years.
Rhynchaeites is an extinct genus of wading bird, likely a stem-group ibis, from the Eocene. It is one of the oldest members of the Threskiornithidae known from fossil remains.
Dasornis is a genus of prehistoric pseudotooth birds. These were probably close relatives of either pelicans and storks or waterfowl; they are placed in the order Odontopterygiformes to account for this uncertainty.
Gigantornis eaglesomei is a very large prehistoric bird described from a fragmentary specimen from the Eocene of Nigeria. It was originally described as a representative of the albatross family, Diomedeidae, but was later referred to the pseudotooth or bony-toothed bird family, Pelagornithidae. Gigantornis is one of the largest pseudotooth birds, with an inferred wingspan of about 6 m (20 ft) it is among the largest birds ever.
Eurofluvioviridavis is a genus of extinct primitive birds from the Middle Eocene Messel Pit, Germany. It contains a single species, Eurofluvioviridavis robustipes. It is related to Avolatavis and Vastanavis, other members of the family Vastanavidae.
Eostrix is a genus of extinct primitive owls in the family Protostrigidae, along with Oligostrix and Minerva. These owls date from the early Eocene of the United States, Europe, and Mongolia. They have been described based on fossil remains. The genus was created by Pierce Brodkorb in 1971 to place a fossil species known until that time as Protostrix mimica.
The magnificent frigatebird, frigate petrel or man o' war is a seabird of the frigatebird family Fregatidae. With a length of 89–114 centimetres and wingspan of 2.17–2.44 m it is the largest species of frigatebird. It occurs over tropical and subtropical waters off America, between northern Mexico and Perú on the Pacific coast and between Florida and southern Brazil along the Atlantic coast. There are also populations on the Galápagos Islands in the Pacific and the Cape Verde islands in the Atlantic. It is one of the fastest birds in the world, flying at speeds of up to 95 miles per hour.
The order Suliformes is an order of birds recognised by the International Ornithologist's Union. Regarding the recent evidence that the traditional Pelecaniformes is polyphyletic, it has been suggested that the group be divided to reflect the true evolutionary relationships; a 2017 study indicated that they are most closely related to Otidiformes (bustards) and Ciconiiformes (storks).
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.
Tonsala is an extinct genus of Plotopteridae, a family of flightless seabird similar in biology with penguins, but more closely related to modern cormorants. The genus is known from terrains dated from the Late Oligocene of the State of Washington and Japan.
Phocavis is an extinct genus of flightless seabird, belonging to the family Plotopteridae, and distantly related with modern cormorants. Its fossils, found in the Keasey Formation in Oregon, are dated from the Late Eocene.
Cyrilavis is an extinct genus of halcyornithid bird from the Early Eocene Fossil Butte Member of the Green River Formation, United States. The genus contains two species, Cyrilavis olsoni and Cyrilavis colburnorum.
The Green River Formation is a geological formation located in the Intermountain West of the United States, in the states of Colorado, Utah, and Wyoming. It comprises sediments deposited during the Early Eocene in a series of large freshwater lakes: Lake Gosiute, Lake Uinta, and Fossil Lake. It preserves a high diversity of freshwater fish, birds, reptiles, and mammals, with some sections of the formation qualifying as Konservat-Lagerstätten due to their extremely well-preserved fossils.
The Sankarewang Formation is an ?Eocene-aged geological formation in Sumatra, Indonesia near Padang. It is among the very few Paleogene fossil deposits from Southeast Asia that preserves a freshwater ecosystem, and contains many of the earliest records of freshwater fish taxa that now predominate the region. Many of the fishes from this formation are well-preserved as articulated skeletons. The fossils of the formation have been known since the 1870s, although they only received significant attention during the 1930s and again starting from the mid-2010s.
