Penguins are a group of aquatic flightless birds from the order Sphenisciformes of the family Spheniscidae. They live almost exclusively in the Southern Hemisphere: only one species, the Galápagos penguin, is found north of the Equator. Highly adapted for life in the ocean water, penguins have countershaded dark and white plumage and flippers for swimming. Most penguins feed on krill, fish, squid and other forms of sea life which they catch with their bills and swallow whole while swimming. A penguin has a spiny tongue and powerful jaws to grip slippery prey.
Charadriiformes is a diverse order of small to medium-large birds. It includes about 390 species and has members in all parts of the world. Most charadriiform birds live near water and eat invertebrates or other small animals; however, some are pelagic (seabirds), others frequent deserts, and a few are found in dense forest. Members of this group can also collectively be referred to as shorebirds.
The mousebirds are birds in the order Coliiformes. They are the sister group to the clade Eucavitaves, which includes the Leptosomiformes, Trogoniformes (trogons), Bucerotiformes, Piciformes and Coraciformes. This group is now confined to sub-Saharan Africa, and it is the only bird order confined entirely to that continent, with the possible exception of turacos which are considered by some as the distinct order Musophagiformes, and the cuckoo roller, which is the only member of the order Leptosomiformes, and which is found in Madagascar but not mainland Africa. Mousebirds had a wider range in the Paleogene, with a widespread distribution in Europe and North America during the Paleocene.
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.
Waimanu is a genus of early penguin which lived during the Paleocene, soon after the Cretaceous–Paleogene extinction event, around 62–60 million years ago. It was about the size of an emperor penguin. It is one of the most important bird fossils for understanding the origin and evolution of birds because of the time period it comes from, and the position of penguins near the base of the bird family tree.
Archaeospheniscus lopdelli was the largest species of the extinct penguin genus Archaeospheniscus, standing about 90–120 cm (35–47 in) high, or somewhat less than the extant emperor penguin. It is only known from bones of a single individual which was found in the Late Oligocene Kokoamu Greensand Formation at Duntroon, New Zealand. Bones apparently belonging to this species are now also known from the Late Eocene La Meseta Formation on Seymour Island, Antarctica.
Palaeeudyptes antarcticus, also referred to as the narrow-flippered penguin, is the type species of the extinct penguin genus Palaeeudyptes. It was a huge species, albeit probably with a large size variation. Although the size range can only be loosely estimated, the birds seem to have stood between 43 and 55 inches high in life, placing this species and its congener Palaeeudyptes marplesi among the largest penguin species known. It was the last known Palaeeudyptes species, and although the exact time when it lived is not precisely determined, it may have evolved from P. marplesi, or they might even have been a single species which slightly decreased in size over time.
Gun Penguin is an extinct species of the extinct penguin genus Palaeeudyptes. It was a bit smaller than its congener Palaeeudyptes antarcticus of New Zealand, standing between 110 and 125 cm high, approximately the size of the emperor penguin. It is known from dozens of fossil bones from Middle or Late Eocene strata of the La Meseta Formation on Seymour Island, Antarctica. Initially, it was described as a separate genus, Eosphaeniscus. However, this was based on a single weathered and broken tarsometatarsus. Better material recovered later showed that the species belongs into the present genus.
Palaeeudyptes klekowskii, is an extinct species of the penguin genus Palaeeudyptes. It was until recently thought to have been approximately the size of its congener Palaeeudyptes antarcticus, which would mean it was somewhat larger than the modern emperor penguin, but a new study shows it was in fact almost twice as tall. Its maximum height is estimated to be up to 2 meters (6.6 ft) and maximum body mass up to 116 kg (256 lb). Knowledge of it comes from an extensive collection of fossil bones from the Late Eocene of the La Meseta Formation on Seymour Island, Antarctica. P. klekowskii was at first not recognized as a distinct species, and despite the coexistence of two so closely related species of similar size as Palaeeudyptes gunnari and P. klekowskii seeming somewhat improbable, the amount of fossil material suggests that the two species are indeed diagnosably different.
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.
Odontopteryx is a genus of the extinct pseudotooth birds or pelagornithids. These were probably rather close relatives of either pelicans and storks, or of waterfowl, and are here placed in the order Odontopterygiformes to account for this uncertainty.
Australornis is a genus of extinct seabird discovered in New Zealand. It lived in the Paleocene epoch, 60.5 to 61.6 million years ago (Ma). The type species name originates from australis, Latin for "southern", and ornis, the Greek word for "bird", and lovei commemorates Leigh Love, an amateur paleontologist who discovered it.
Kumimanu is an extinct genus of giant penguin, which lived around 60 to 56 million years ago. The type species is K. biceae, which arose after the extinction of the non-avian dinosaurs. Fossils were found in New Zealand, and the discovery was announced in December 2017. A second species, Kumimanu fordycei, was named in February 2023.
Muriwaimanu is an extinct genus of early penguin.
Sequiwaimanu is an extinct genus of early penguin. The type species, Sequiwaimanu rosieae, was named and described by Gerald Mayr in 2018.
Kupoupou is an extinct genus of bird from the Paleocene-aged Takatika Grit of the Chatham Islands, New Zealand which is believed to be the oldest penguin genus known to date. The type species, K. stilwelli, was named and described by Blokland et al. in 2019.
The Waipara Greensand is a geological rock unit found in Canterbury, New Zealand. It dates from just after the Cretaceous–Paleogene extinction event, the Thanetian and Selandian, around 61–62 million years ago in the early Palaeocene. It is well known for its fossils, particularly for containing the oldest penguins (Sphenisciformes).
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.
Klallamornis is an extinct genus of Plotopteridae, a family of large, flightless birds related to modern cormorants, darters, gannets, and boobies. This genus included the largest North American plotopterids. Its remains can be found in Late Eocene to Late Oligocene rocks from the Makah Formation, the overlying Pysht Formation and the Lincoln Creek Formation of the State of Washington. During its existence, Klallamornis was the largest plotopterid on the North American continent. The first fossil remains attributed to the taxon were collected in 1983, although the genus wasn't described until 2016.
