104-538: For prehistoric genera, see List of penguins#Fossil genera Penguins are a group of aquatic flightless birds from the family Spheniscidae ( / s f ɪ ˈ n ɪ s ɪ d iː , - d aɪ / ) of the order Sphenisciformes ( / s f ɪ ˈ n ɪ s ə f ɔːr m iː z / ). They live almost exclusively in the Southern Hemisphere : only one species , the Galápagos penguin , is found north of
208-518: A leopard seal ) has difficulty distinguishing between a white penguin belly and the reflective water surface. The dark plumage on their backs camouflages them from above. Gentoo penguins are the fastest underwater birds in the world. They are capable of reaching speeds up to 36 km (about 22 miles) per hour while searching for food or escaping from predators. They are also able to dive to depths of 170–200 meters (about 560–660 feet). The small penguins do not usually dive deep; they catch their prey near
312-620: A monophyletic lineage, or whether gigantism was evolved independently in a restricted Palaeeudyptinae and the Anthropornithinae – whether they were considered valid, or whether there was a wide size range present in the Palaeeudyptinae as delimited (i.e., including Anthropornis nordenskjoeldi ). The oldest well-described giant penguin, the 5-foot (1.5 m)-tall Icadyptes salasi , existed as far north as northern Peru about 36 mya. Gigantic penguins had disappeared by
416-469: A basis of morphological and physiological facts as possible, and one in which "place is found for all observational and experimental data relating, even if indirectly, to the constitution, subdivision, origin, and behaviour of species and other taxonomic groups". Ideals can, it may be said, never be completely realized. They have, however, a great value of acting as permanent stimulants, and if we have some, even vague, ideal of an "omega" taxonomy we may progress
520-557: A chaotic and disorganized taxonomic literature. He not only introduced the standard of class, order, genus, and species, but also made it possible to identify plants and animals from his book, by using the smaller parts of the flower (known as the Linnaean system ). Plant and animal taxonomists regard Linnaeus' work as the "starting point" for valid names (at 1753 and 1758 respectively). Names published before these dates are referred to as "pre-Linnaean", and not considered valid (with
624-543: A continuous circumpolar flow only around 30 mya, on the one hand forcing the Antarctic cooling, and on the other facilitating the eastward expansion of Spheniscus to South America and eventually beyond. Despite this, there is no fossil evidence to support the idea of crown radiation from the Antarctic continent in the Paleogene, although DNA study favors such a radiation. Later, an interspersed period of slight warming
728-703: A derivation from Welsh pen , 'head' and gwyn , 'white', including the Oxford English Dictionary , the American Heritage Dictionary , the Century Dictionary and Merriam-Webster , on the basis that the name was originally applied to the great auk, either because it was found on White Head Island ( Welsh : Pen Gwyn ) in Newfoundland, or because it had white circles around its eyes (though
832-443: A different sense, to mean the delimitation of species (not subspecies or taxa of other ranks), using whatever investigative techniques are available, and including sophisticated computational or laboratory techniques. Thus, Ernst Mayr in 1968 defined " beta taxonomy " as the classification of ranks higher than species. An understanding of the biological meaning of variation and of the evolutionary origin of groups of related species
936-460: A group of penguins on land is a waddle , and a group of penguins in the water is a raft . Since 1871, the Latin word Pinguinus has been used in scientific classification to name the genus of the great auk ( Pinguinus impennis , meaning "plump or fat without flight feathers "), which became extinct in the mid-19th century. As confirmed by a 2004 genetic study, the genus Pinguinus belongs in
1040-455: A little way down the Greek alphabet. Some of us please ourselves by thinking we are now groping in a "beta" taxonomy. Turrill thus explicitly excludes from alpha taxonomy various areas of study that he includes within taxonomy as a whole, such as ecology, physiology, genetics, and cytology. He further excludes phylogenetic reconstruction from alpha taxonomy. Later authors have used the term in
1144-485: A mostly Subantarctic distribution centred on South America ; some, however, range quite far northwards. They all lack carotenoid colouration and the former genus has a conspicuous banded head pattern; they are unique among living penguins by nesting in burrows. This group probably radiated eastwards with the Antarctic Circumpolar Current out of the ancestral range of modern penguins throughout
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#17327719256121248-504: A notable renaissance, principally with respect to theoretical content. Part of the theoretical material has to do with evolutionary areas (topics e and f above), the rest relates especially to the problem of classification. Taxonomy is that part of Systematics concerned with topics (a) to (d) above. A whole set of terms including taxonomy, systematic biology, systematics , scientific classification, biological classification, and phylogenetics have at times had overlapping meanings – sometimes
1352-545: A range map is not available, a description of the penguin's range is provided. Ranges are based on the IOC World Bird List for that species unless otherwise noted. Population estimates are of the number of mature individuals and are taken from the IUCN Red List. This list follows the taxonomic treatment (designation and order of species) and nomenclature (scientific and common names) of version 13.2 of
1456-477: A single continuum, as per the scala naturae (the Natural Ladder). This, as well, was taken into consideration in the great chain of being. Advances were made by scholars such as Procopius , Timotheus of Gaza , Demetrios Pepagomenos , and Thomas Aquinas . Medieval thinkers used abstract philosophical and logical categorizations more suited to abstract philosophy than to pragmatic taxonomy. During
1560-652: A sub-area of systematics (definition 2), invert that relationship (definition 6), or appear to consider the two terms synonymous. There is some disagreement as to whether biological nomenclature is considered a part of taxonomy (definitions 1 and 2), or a part of systematics outside taxonomy. For example, definition 6 is paired with the following definition of systematics that places nomenclature outside taxonomy: In 1970, Michener et al. defined "systematic biology" and "taxonomy" (terms that are often confused and used interchangeably) in relation to one another as follows: Systematic biology (hereafter called simply systematics)
1664-524: A truly scientific attempt to classify organisms did not occur until the 18th century, with the possible exception of Aristotle, whose works hint at a taxonomy. Earlier works were primarily descriptive and focused on plants that were useful in agriculture or medicine. There are a number of stages in this scientific thinking. Early taxonomy was based on arbitrary criteria, the so-called "artificial systems", including Linnaeus 's system of sexual classification for plants (Linnaeus's 1735 classification of animals
1768-497: Is a critical component of the taxonomic process. As a result, it informs the user as to what the relatives of the taxon are hypothesized to be. Biological classification uses taxonomic ranks, including among others (in order from most inclusive to least inclusive): Domain , Kingdom , Phylum , Class , Order , Family , Genus , Species , and Strain . The "definition" of a taxon is encapsulated by its description or its diagnosis or by both combined. There are no set rules governing
1872-400: Is a novel analysis of the variation patterns in a particular taxon . This analysis may be executed on the basis of any combination of the various available kinds of characters, such as morphological, anatomical , palynological , biochemical and genetic . A monograph or complete revision is a revision that is comprehensive for a taxon for the information given at a particular time, and for
1976-458: Is a resource for fossils. Biological taxonomy is a sub-discipline of biology , and is generally practiced by biologists known as "taxonomists", though enthusiastic naturalists are also frequently involved in the publication of new taxa. Because taxonomy aims to describe and organize life , the work conducted by taxonomists is essential for the study of biodiversity and the resulting field of conservation biology . Biological classification
2080-405: Is different from albinism. Isabelline penguins tend to live shorter lives than normal penguins, as they are not well-camouflaged against the deep and are often passed over as mates. Penguins for the most part breed in large colonies, the exceptions being the yellow-eyed and Fiordland species; these colonies may range in size from as few as 100 pairs for gentoo penguins to several hundred thousand in
2184-419: Is even more important for the second stage of taxonomic activity, the sorting of species into groups of relatives ("taxa") and their arrangement in a hierarchy of higher categories. This activity is what the term classification denotes; it is also referred to as "beta taxonomy". How species should be defined in a particular group of organisms gives rise to practical and theoretical problems that are referred to as
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#17327719256122288-460: Is much greater than in air). The emperor penguin has a maximum feather density of about nine feathers per square centimeter which is actually much lower than other birds that live in Antarctic environments. However, they have been identified as having at least four different types of feather: in addition to the traditional feather, the emperor has afterfeathers , plumules , and filoplumes . The afterfeathers are downy plumes that attach directly to
2392-487: Is or includes the paleeudyptines as recognized today – occurred on most Antarctic and Subantarctic coasts. Size plasticity was significant at this initial stage of radiation : on Seymour Island , Antarctica, for example, around 10 known species of penguins ranging in size from medium to large apparently coexisted some 35 mya during the Priabonian (Late Eocene). It is not known whether the palaeeudyptines constitute
2496-486: Is sometimes called " higher waterbirds " to distinguish them from the more ancient waterfowl . This group contains such birds as storks , rails , and the seabirds , with the possible exception of the Charadriiformes . Inside this group, penguin relationships are far less clear. Depending on the analysis and dataset, a close relationship to Ciconiiformes or to Procellariiformes has been suggested. Some think
2600-428: Is sometimes used in botany in place of phylum ), class , order , family , genus , and species . The Swedish botanist Carl Linnaeus is regarded as the founder of the current system of taxonomy, as he developed a ranked system known as Linnaean taxonomy for categorizing organisms and binomial nomenclature for naming organisms. With advances in the theory, data and analytical technology of biological systematics,
2704-449: Is the scientific study of naming, defining ( circumscribing ) and classifying groups of biological organisms based on shared characteristics. Organisms are grouped into taxa (singular: taxon) and these groups are given a taxonomic rank ; groups of a given rank can be aggregated to form a more inclusive group of higher rank, thus creating a taxonomic hierarchy. The principal ranks in modern use are domain , kingdom , phylum ( division
2808-400: Is the field that (a) provides scientific names for organisms, (b) describes them, (c) preserves collections of them, (d) provides classifications for the organisms, keys for their identification, and data on their distributions, (e) investigates their evolutionary histories, and (f) considers their environmental adaptations. This is a field with a long history that in recent years has experienced
2912-402: Is used by parents and chicks to locate one another in crowded colonies . Their eyes are adapted for underwater vision and are their primary means of locating prey and avoiding predators; in air it has been suggested that they are nearsighted , although research has not supported this hypothesis. Penguins have a thick layer of insulating feathers that keeps them warm in water (heat loss in water
3016-470: The Antarctic Peninsula and Patagonia have not yielded Paleogene fossils of the subfamily. Also, the earliest spheniscine lineages are those with the most southern distribution. The genus Aptenodytes appears to be the basalmost divergence among living penguins. They have bright yellow-orange neck, breast, and bill patches; incubate by placing their eggs on their feet, and when they hatch
3120-529: The Aristotelian system , with additions concerning the philosophical and existential order of creatures. This included concepts such as the great chain of being in the Western scholastic tradition, again deriving ultimately from Aristotle. The Aristotelian system did not classify plants or fungi , due to the lack of microscopes at the time, as his ideas were based on arranging the complete world in
3224-640: The Campanian – Maastrichtian boundary, around 70–68 mya. The oldest known fossil penguin species is Waimanu manneringi , which lived 62 mya in New Zealand. While they were not as well-adapted to aquatic life as modern penguins, Waimanu were flightless, with short wings adapted for deep diving. They swam on the surface using mainly their feet, but the wings were – as opposed to most other diving birds (both living and extinct) – already adapting to underwater locomotion. Perudyptes from northern Peru
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3328-613: The Chattian (Late Oligocene), starting approximately 28 mya. While the two genera separated during this time, the present-day diversity is the result of a Pliocene radiation, taking place some 4–2 mya. The Megadyptes – Eudyptes clade occurs at similar latitudes (though not as far north as the Galápagos penguin ), has its highest diversity in the New Zealand region, and represents a westward dispersal. They are characterized by hairy yellow ornamental head feathers; their bills are at least partly red. These two genera diverged apparently in
3432-460: 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. They spend about half of their lives on land and
3536-619: The International Ornithologists' Union , distributed among six genera. Many species of fossil penguins are known from the Paleocene onwards; however, their exact number and taxonomy are unsettled due to ongoing discoveries. Conservation status codes listed follow the International Union for Conservation of Nature (IUCN) Red List of Threatened Species . Range maps are provided wherever possible; if
3640-585: The Neomura , the clade that groups together the Archaea and Eucarya , would have evolved from Bacteria, more precisely from Actinomycetota . His 2004 classification treated the archaeobacteria as part of a subkingdom of the kingdom Bacteria, i.e., he rejected the three-domain system entirely. Stefan Luketa in 2012 proposed a five "dominion" system, adding Prionobiota ( acellular and without nucleic acid ) and Virusobiota (acellular but with nucleic acid) to
3744-512: The Renaissance and the Age of Enlightenment , categorizing organisms became more prevalent, and taxonomic works became ambitious enough to replace the ancient texts. This is sometimes credited to the development of sophisticated optical lenses, which allowed the morphology of organisms to be studied in much greater detail. One of the earliest authors to take advantage of this leap in technology
3848-493: The phylogenetic taxon Spheniscidae to what here is referred to as Spheniscinae. Furthermore, they restrict the phylogenetic taxon Sphenisciformes to flightless taxa, and establish the phylogenetic taxon Pansphenisciformes as equivalent to the Linnean taxon Sphenisciformes, i.e., including any flying basal "proto-penguins" to be discovered eventually. Given that neither the relationships of the penguin subfamilies to each other nor
3952-439: The species problem . The scientific work of deciding how to define species has been called microtaxonomy. By extension, macrotaxonomy is the study of groups at the higher taxonomic ranks subgenus and above, or simply in clades that include more than one taxon considered a species, expressed in terms of phylogenetic nomenclature . While some descriptions of taxonomic history attempt to date taxonomy to ancient civilizations,
4056-467: The vertebrates ), as well as groups like the sharks and cetaceans , are commonly used. His student Theophrastus (Greece, 370–285 BC) carried on this tradition, mentioning some 500 plants and their uses in his Historia Plantarum . Several plant genera can be traced back to Theophrastus, such as Cornus , Crocus , and Narcissus . Taxonomy in the Middle Ages was largely based on
4160-578: The "heterothermic loophole" that penguins utilize in order to survive in Antarctica. All extant penguins, even those that live in warmer climates, have a counter-current heat exchanger called the humeral plexus. The flippers of penguins have at least three branches of the axillary artery, which allows cold blood to be heated by blood that has already been warmed and limits heat loss from the flippers. This system allows penguins to efficiently use their body heat and explains why such small animals can survive in
4264-488: The 1960s. In 1958, Julian Huxley used the term clade . Later, in 1960, Cain and Harrison introduced the term cladistic . The salient feature is arranging taxa in a hierarchical evolutionary tree , with the desideratum that all named taxa are monophyletic. A taxon is called monophyletic if it includes all the descendants of an ancestral form. Groups that have descendant groups removed from them are termed paraphyletic , while groups representing more than one branch from
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4368-733: The IOC World Bird List. Where the taxonomy proposed by the IOC World Bird List conflicts with the taxonomy followed by the IUCN or the 2023 edition of The Clements Checklist of Birds of the World , the disagreement is noted next to the species's common name (for nomenclatural disagreements) or scientific name (for taxonomic disagreements). The International Ornithologists' Union (IOU) recognises 18 species of penguins in six genera. This list does not include hybrid species , extinct prehistoric species, or putative species not yet accepted by
4472-1108: The IOU. Family Spheniscidae [REDACTED] 1,084,320–1,228,320 breeding pairs [REDACTED] [REDACTED] 256,500 breeding pairs [REDACTED] [REDACTED] 1,084,320–1,228,320 breeding pairs [REDACTED] [REDACTED] 8,000,000 [REDACTED] [REDACTED] 774,000 [REDACTED] [REDACTED] 469,760 [REDACTED] [REDACTED] 1,200 [REDACTED] [REDACTED] 23,800 [REDACTED] [REDACTED] 2,200,000–3,200,000 [REDACTED] [REDACTED] 41,700 [REDACTED] [REDACTED] 2,600–3,000 [REDACTED] [REDACTED] 6,300,000 breeding pairs [REDACTED] [REDACTED] 1,340,000–1,660,000 [REDACTED] [REDACTED] 413,700 [REDACTED] [REDACTED] 2,500,000 [REDACTED] [REDACTED] 12,500–50,000 [REDACTED] [REDACTED] 63,000 [REDACTED] [REDACTED] 150,000 [REDACTED] The Early Oligocene genus Cruschedula
4576-535: The Linnaean system has transformed into a system of modern biological classification intended to reflect the evolutionary relationships among organisms, both living and extinct. The exact definition of taxonomy varies from source to source, but the core of the discipline remains: the conception, naming, and classification of groups of organisms. As points of reference, recent definitions of taxonomy are presented below: The varied definitions either place taxonomy as
4680-524: The Middle Miocene ( Langhian , roughly 15–14 mya), although the living species of Eudyptes are the product of a later radiation, stretching from about the late Tortonian (Late Miocene, 8 mya) to the end of the Pliocene. The geographical and temporal pattern of spheniscine evolution corresponds closely to two episodes of global cooling documented in the paleoclimatic record . The emergence of
4784-491: The Origin of Species (1859) led to a new explanation for classifications, based on evolutionary relationships. This was the concept of phyletic systems, from 1883 onwards. This approach was typified by those of Eichler (1883) and Engler (1886–1892). The advent of cladistic methodology in the 1970s led to classifications based on the sole criterion of monophyly , supported by the presence of synapomorphies . Since then,
4888-696: The Southern Hemisphere, they noticed their similar appearance to the great auk of the Northern Hemisphere and named them after this bird, although they are not closely related. The etymology of the word penguin is still debated. The English word is not apparently of French , Breton or Spanish origin (the latter two are attributed to the French word pingouin ), but first appears in English or Dutch. Some dictionaries suggest
4992-540: The Spheniscinae lies probably in the latest Paleogene and, geographically, it must have been much the same as the general area in which the order evolved: the oceans between the Australia-New Zealand region and the Antarctic. Presumably diverging from other penguins around 40 mya, it seems that the Spheniscinae were for quite some time limited to their ancestral area, as the well-researched deposits of
5096-681: The Spheniscinae, as Aptenodytes ' autapomorphies are, in most cases, fairly pronounced adaptations related to that genus' extreme habitat conditions. As the former genus, Pygoscelis seems to have diverged during the Bartonian, but the range expansion and radiation that led to the present-day diversity probably did not occur until much later; around the Burdigalian stage of the Early Miocene , roughly 20–15 mya. The genera Spheniscus and Eudyptula contain species with
5200-541: The Subantarctic lineage at the end of the Bartonian corresponds with the onset of the slow period of cooling that eventually led to the ice ages some 35 million years later. With habitat on the Antarctic coasts declining, by the Priabonian more hospitable conditions for most penguins existed in the Subantarctic regions rather than in Antarctica itself. Notably, the cold Antarctic Circumpolar Current also started as
5304-531: The air. In the water, however, penguins are astonishingly agile. Penguins' swimming looks very similar to birds' flight in the air. Within the smooth plumage a layer of air is preserved, ensuring buoyancy. The air layer also helps insulate the birds in cold waters. On land, penguins use their tails and wings to maintain balance for their upright stance. All penguins are countershaded for camouflage – that is, they have black backs and wings with white fronts. A predator looking up from below (such as an orca or
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#17327719256125408-522: The animal and plant kingdoms toward the end of the 18th century, well before Charles Darwin's On the Origin of Species was published. The pattern of the "Natural System" did not entail a generating process, such as evolution, but may have implied it, inspiring early transmutationist thinkers. Among early works exploring the idea of a transmutation of species were Zoonomia in 1796 by Erasmus Darwin (Charles Darwin's grandfather), and Jean-Baptiste Lamarck 's Philosophie zoologique of 1809. The idea
5512-422: The case of king, macaroni and chinstrap penguins. Living in colonies results in a high level of social interaction between birds, which has led to a large repertoire of visual as well as vocal displays in all penguin species. Agonistic displays are those intended to confront or drive off, or alternately appease and avoid conflict with, other individuals. Penguins form monogamous pairs for a breeding season, though
5616-421: The chicks are almost naked. This genus has a distribution centred on the Antarctic coasts and barely extends to some Subantarctic islands today. Pygoscelis contains species with a fairly simple black-and-white head pattern; their distribution is intermediate, centred on Antarctic coasts but extending somewhat northwards from there. In external morphology , these apparently still resemble the common ancestor of
5720-550: The definition of taxa, but the naming and publication of new taxa is governed by sets of rules. In zoology , the nomenclature for the more commonly used ranks ( superfamily to subspecies ), is regulated by the International Code of Zoological Nomenclature ( ICZN Code ). In the fields of phycology , mycology , and botany , the naming of taxa is governed by the International Code of Nomenclature for algae, fungi, and plants ( ICN ). The initial description of
5824-515: The emergence of another morphotype in the same area, the similarly sized but more gracile Palaeospheniscinae , as well as the radiation that gave rise to the current biodiversity of penguins. Modern penguins constitute two undisputed clades and another two more basal genera with more ambiguous relationships. To help resolve the evolution of this order , 19 high-coverage genomes that, together with two previously published genomes, encompass all extant penguin species have been sequenced. The origin of
5928-599: The end of the Paleogene , around 25 mya. Their decline and disappearance coincided with the spread of the Squalodontidae and other primitive, fish-eating toothed whales , which competed with them for food and were ultimately more successful. A new lineage, the Paraptenodytes , which includes smaller and stout-legged forms, had already arisen in southernmost South America by that time. The early Neogene saw
6032-399: The entire world. Other (partial) revisions may be restricted in the sense that they may only use some of the available character sets or have a limited spatial scope. A revision results in a conformation of or new insights in the relationships between the subtaxa within the taxon under study, which may lead to a change in the classification of these subtaxa, the identification of new subtaxa, or
6136-494: The evidentiary basis has been expanded with data from molecular genetics that for the most part complements traditional morphology . Naming and classifying human surroundings likely began with the onset of language. Distinguishing poisonous plants from edible plants is integral to the survival of human communities. Medicinal plant illustrations show up in Egyptian wall paintings from c. 1500 BC , indicating that
6240-538: The evolutionary history of penguins have been published since 2005. The basal penguins lived around the time of the Cretaceous–Paleogene extinction event in the general area of southern New Zealand and Byrd Land , Antarctica. Due to plate tectonics , these areas were at that time less than 1,500 kilometres (930 mi) apart rather than 4,000 kilometres (2,500 mi). The most recent common ancestor of penguins and Procellariiformes can be roughly dated to
6344-400: The exception is the little penguin, which can raise two or three broods in a season. Penguin eggs are smaller than any other bird species when compared proportionally to the weight of the parent birds; at 52 g (2 oz), the little penguin egg is 4.7% of its mothers' weight, and the 450 g (1 lb) emperor penguin egg is 2.3%. The relatively thick shell forms between 10 and 16% of
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#17327719256126448-524: The exception of spiders published in Svenska Spindlar ). Even taxonomic names published by Linnaeus himself before these dates are considered pre-Linnaean. Modern taxonomy is heavily influenced by technology such as DNA sequencing , bioinformatics , databases , and imaging . A pattern of groups nested within groups was specified by Linnaeus' classifications of plants and animals, and these patterns began to be represented as dendrograms of
6552-473: The extreme cold of the Antarctic winter, the females are at sea fishing for food, leaving the males to brave the weather by themselves. They often huddle together to keep warm and rotate positions to make sure that each penguin gets a turn in the centre of the heat pack. Calculations of the heat loss and retention ability of marine endotherms suggest that most extant penguins are too small to survive in such cold environments. In 2007, Thomas and Fordyce wrote about
6656-678: The extreme cold. They can drink salt water because their supraorbital gland filters excess salt from the bloodstream. The salt is excreted in a concentrated fluid from the nasal passages. The great auk of the Northern Hemisphere, now extinct, was superficially similar to penguins, and the word penguin was originally used for that bird centuries ago. They are only distantly related to the penguins, but are an example of convergent evolution . Around one in 50,000 penguins (of most species) are born with brown rather than black plumage. These are called isabelline penguins. Isabellinism
6760-425: The family of the auks (Alcidae), within the order of the Charadriiformes . The birds currently known as penguins were discovered later and were so named by sailors because of their physical resemblance to the great auk. Despite this resemblance, however, they are not auks, and are not closely related to the great auk. They do not belong in the genus Pinguinus , and are not classified in the same family and order as
6864-486: The first modern groups tied to fossil ancestors was birds. Using the then newly discovered fossils of Archaeopteryx and Hesperornis , Thomas Henry Huxley pronounced that they had evolved from dinosaurs, a group formally named by Richard Owen in 1842. The resulting description, that of dinosaurs "giving rise to" or being "the ancestors of" birds, is the essential hallmark of evolutionary taxonomic thinking. As more and more fossil groups were found and recognized in
6968-687: The formal naming of clades. Linnaean ranks are optional and have no formal standing under the PhyloCode , which is intended to coexist with the current, rank-based codes. While popularity of phylogenetic nomenclature has grown steadily in the last few decades, it remains to be seen whether a majority of systematists will eventually adopt the PhyloCode or continue using the current systems of nomenclature that have been employed (and modified, but arguably not as much as some systematists wish) for over 250 years. Well before Linnaeus, plants and animals were considered separate Kingdoms. Linnaeus used this as
7072-485: The great auk. They were classified in 1831 by Charles Lucien Bonaparte in several distinct genera within the family Spheniscidae and order Sphenisciformes . The family name of Spheniscidae was given by Charles Lucien Bonaparte from the genus Spheniscus , the name of that genus comes from the Greek word σφήν sphēn " wedge " used for the shape of an African penguin 's swimming flippers. Some recent sources apply
7176-569: The head was black). However, the Welsh word pen can also be used to mean 'front' and, in a maritime context, pen blaen means 'front end or part, bow (of a ship), prow'. An alternative etymology links the word to Latin pinguis , which means 'fat' or 'oil'. Support for this etymology can be found in the alternative Germanic word for penguin, fettgans or 'fat-goose', and the related Dutch word vetgans . Adult male penguins are sometimes called cocks , females sometimes called hens ;
7280-466: The late 19th and early 20th centuries, palaeontologists worked to understand the history of animals through the ages by linking together known groups. With the modern evolutionary synthesis of the early 1940s, an essentially modern understanding of the evolution of the major groups was in place. As evolutionary taxonomy is based on Linnaean taxonomic ranks, the two terms are largely interchangeable in modern use. The cladistic method has emerged since
7384-414: The main feathers and were once believed to account for the bird's ability to conserve heat when under water; the plumules are small down feathers that attach directly to the skin, and are much more dense in penguins than other birds; lastly the filoplumes are small (less than 1 cm long) naked shafts that end in a splay of fibers— filoplumes were believed to give flying birds a sense of where their plumage
7488-401: The merger of previous subtaxa. Taxonomic characters are the taxonomic attributes that can be used to provide the evidence from which relationships (the phylogeny ) between taxa are inferred. Kinds of taxonomic characters include: The term " alpha taxonomy " is primarily used to refer to the discipline of finding, describing, and naming taxa , particularly species. In earlier literature,
7592-557: The only species to occur north of the Equator is the Galapagos penguin . The only group of birds other than the ratites to be entirely flightless, penguins are extremely adapted to their aquatic lifestyle, with a streamlined shape that minimizes drag, countershaded dark-and-white plumage , dense bones, powerful flippers, and insulating feathers that allow them to withstand very low temperatures on land and in water. There are currently 18 extant species of penguins recognised by
7696-644: The other half in the sea. The largest living species is the emperor penguin ( Aptenodytes forsteri ): on average, adults are about 1.1 m (3 ft 7 in) tall and weigh 35 kg (77 lb). The smallest penguin species is the little blue penguin ( Eudyptula minor ), also known as the fairy penguin, which stands around 30–33 cm (12–13 in) tall and weighs 1.2–1.3 kg (2.6–2.9 lb). Today, larger penguins generally inhabit colder regions, and smaller penguins inhabit regions with temperate or tropical climates . Some prehistoric penguin species were enormous: as tall or heavy as an adult human. There
7800-473: The penguin-like plotopterids (usually considered relatives of cormorants and anhingas ) may actually be a sister group of the penguins and those penguins may have ultimately shared a common ancestor with the Pelecaniformes and consequently would have to be included in that order, or that the plotopterids were not as close to other pelecaniforms as generally assumed, which would necessitate splitting
7904-593: The penguins, puffins have a white chest, black back and short stubby wings providing excellent swimming ability in icy water. But, unlike penguins, puffins can fly, as flightless birds would not survive alongside land-based predators such as polar bears and foxes; there are no such predators in the Antarctic. Their similarities indicate that similar environments, although at great distances, can result in similar evolutionary developments, i.e. convergent evolution . Penguins are superbly adapted to aquatic life. Their wings have evolved to become flippers, useless for flight in
8008-497: The placement of the penguins in the avian phylogeny is presently resolved, this is confusing, so the established Linnean system is followed here. The number of penguin species is typically listed as between seventeen and nineteen. The International Ornithologists' Union recognizes six genera and eighteen species: Although the evolutionary and biogeographic history of Sphenisciformes is well-researched, many prehistoric forms are not fully described . Some seminal articles about
8112-434: The possibilities of closer co-operation with their cytological, ecological and genetics colleagues and to acknowledge that some revision or expansion, perhaps of a drastic nature, of their aims and methods, may be desirable ... Turrill (1935) has suggested that while accepting the older invaluable taxonomy, based on structure, and conveniently designated "alpha", it is possible to glimpse a far-distant taxonomy built upon as wide
8216-818: The rank of Order, although both exclude fossil representatives. A separate compilation (Ruggiero, 2014) covers extant taxa to the rank of Family. Other, database-driven treatments include the Encyclopedia of Life , the Global Biodiversity Information Facility , the NCBI taxonomy database , the Interim Register of Marine and Nonmarine Genera , the Open Tree of Life , and the Catalogue of Life . The Paleobiology Database
8320-426: The rate the same pair recouples varies drastically. Most penguins lay two eggs in a clutch, although the two largest species, the emperor and the king penguins , lay only one. With the exception of the emperor penguin, where the male does it all, all penguins share the incubation duties. These incubation shifts can last days and even weeks as one member of the pair feeds at sea. Penguins generally only lay one brood;
8424-407: The same, sometimes slightly different, but always related and intersecting. The broadest meaning of "taxonomy" is used here. The term itself was introduced in 1813 by de Candolle , in his Théorie élémentaire de la botanique . John Lindley provided an early definition of systematics in 1830, although he wrote of "systematic botany" rather than using the term "systematics". Europeans tend to use
8528-544: The strong adaptive autapomorphies of the Sphenisciformes; a sometimes perceived fairly close relationship between penguins and grebes is almost certainly an error based on both groups' strong diving adaptations, which are homoplasies . On the other hand, different DNA sequence datasets do not agree in detail with each other either. What seems clear is that penguins belong to a clade of Neoaves (living birds except for paleognaths and fowl ) that comprises what
8632-639: The surface in dives that normally last only one or two minutes. Larger penguins can dive deep in case of need. Emperor penguins are the world's deepest-diving birds. They can dive to depths of approximately 550 meters (1,800 feet) while searching for food. Penguins either waddle on their feet or slide on their bellies across the snow while using their feet to propel and steer themselves, a movement called "tobogganing", which conserves energy while moving quickly. They also jump with both feet together if they want to move more quickly or cross steep or rocky terrain. Penguins have an average sense of hearing for birds; this
8736-472: The term had a different meaning, referring to morphological taxonomy, and the products of research through the end of the 19th century. William Bertram Turrill introduced the term "alpha taxonomy" in a series of papers published in 1935 and 1937 in which he discussed the philosophy and possible future directions of the discipline of taxonomy. ... there is an increasing desire amongst taxonomists to consider their problems from wider viewpoints, to investigate
8840-482: The terms "systematics" and "biosystematics" for the study of biodiversity as a whole, whereas North Americans tend to use "taxonomy" more frequently. However, taxonomy, and in particular alpha taxonomy , is more specifically the identification, description, and naming (i.e., nomenclature) of organisms, while "classification" focuses on placing organisms within hierarchical groups that show their relationships to other organisms. A taxonomic revision or taxonomic review
8944-510: The three-domain method is the separation of Archaea and Bacteria , previously grouped into the single kingdom Bacteria (a kingdom also sometimes called Monera ), with the Eukaryota for all organisms whose cells contain a nucleus . A small number of scientists include a sixth kingdom, Archaea, but do not accept the domain method. Thomas Cavalier-Smith , who published extensively on the classification of protists , in 2002 proposed that
9048-427: The top rank, dividing the physical world into the vegetable, animal and mineral kingdoms. As advances in microscopy made the classification of microorganisms possible, the number of kingdoms increased, five- and six-kingdom systems being the most common. Domains are a relatively new grouping. First proposed in 1977, Carl Woese 's three-domain system was not generally accepted until later. One main characteristic of
9152-553: The traditional Pelecaniformes into three. A 2014 analysis of whole genomes of 48 representative bird species has concluded that penguins are the sister group of Procellariiformes, from which they diverged about 60 million years ago (95% CI, 56.8–62.7). The distantly related Puffins , which live in the North Pacific and North Atlantic, developed similar characteristics to survive in the Arctic and sub-Arctic environments. Like
9256-436: The traditional three domains. Partial classifications exist for many individual groups of organisms and are revised and replaced as new information becomes available; however, comprehensive, published treatments of most or all life are rarer; recent examples are that of Adl et al., 2012 and 2019, which covers eukaryotes only with an emphasis on protists, and Ruggiero et al., 2015, covering both eukaryotes and prokaryotes to
9360-518: The tree of life are called polyphyletic . Monophyletic groups are recognized and diagnosed on the basis of synapomorphies , shared derived character states. Cladistic classifications are compatible with traditional Linnean taxonomy and the Codes of Zoological and Botanical nomenclature , to a certain extent. An alternative system of nomenclature, the International Code of Phylogenetic Nomenclature or PhyloCode has been proposed, which regulates
9464-642: The uses of different species were understood and that a basic taxonomy was in place. Organisms were first classified by Aristotle ( Greece , 384–322 BC) during his stay on the Island of Lesbos . He classified beings by their parts, or in modern terms attributes , such as having live birth, having four legs, laying eggs, having blood, or being warm-bodied. He divided all living things into two groups: plants and animals . Some of his groups of animals, such as Anhaima (animals without blood, translated as invertebrates ) and Enhaima (animals with blood, roughly
9568-401: The vicinity assist the defending mother in keeping her chick. In some species, such as emperor and king penguins, the chicks assemble in large groups called crèches . List of penguins#Fossil genera Penguins are birds in the family Spheniscidae in the monotypic order Sphenisciformes. They inhabit high-productivity marine habitats, almost exclusively in the Southern Hemisphere;
9672-489: The weight of a penguin egg, presumably to reduce the effects of dehydration and to minimize the risk of breakage in an adverse nesting environment. The yolk, too, is large and comprises 22–31% of the egg. Some yolk often remains when a chick is born, and is thought to help sustain the chick if the parents are delayed in returning with food. When emperor penguin mothers lose a chick, they sometimes attempt to "steal" another mother's chick, usually unsuccessfully as other females in
9776-486: Was Methodus Plantarum Nova (1682), in which he published details of over 18,000 plant species. At the time, his classifications were perhaps the most complex yet produced by any taxonomist, as he based his taxa on many combined characters. The next major taxonomic works were produced by Joseph Pitton de Tournefort (France, 1656–1708). His work from 1700, Institutiones Rei Herbariae , included more than 9000 species in 698 genera, which directly influenced Linnaeus, as it
9880-473: Was a great diversity of species in subantarctic regions, and at least one giant species in a region around 2,000 km south of the equator 35 mya , during the Late Eocene , a climate decidedly warmer than today. The word penguin first appears in literature at the end of the 16th century as a synonym for the great auk . When European explorers discovered what are today known as penguins in
9984-416: Was and whether or not it needed preening, so their presence in penguins may seem inconsistent, but penguins also preen extensively. The emperor penguin has the largest body mass of all penguins, which further reduces relative surface area and heat loss. They also are able to control blood flow to their extremities, reducing the amount of blood that gets cold, but still keeping the extremities from freezing. In
10088-643: Was dated to 42 mya. An unnamed fossil from Argentina proves that, by the Bartonian (Middle Eocene), some 39–38 mya, primitive penguins had spread to South America and were in the process of expanding into Atlantic waters. During the Late Eocene and the Early Oligocene (40–30 mya), some lineages of gigantic penguins existed. Nordenskjoeld's giant penguin was the tallest, growing nearly 1.80 meters (5.9 feet) tall. The New Zealand giant penguin
10192-770: Was ended by the Middle Miocene Climate Transition , a sharp drop in global average temperature from 14 to 12 mya, and similar abrupt cooling events followed at 8 mya and 4 mya; by the end of the Tortonian, the Antarctic ice sheet was already much like today in volume and extent. The emergence of most of today's Subantarctic penguin species almost certainly was caused by this sequence of Neogene climate shifts. Penguin ancestry beyond Waimanu remains unknown and not well-resolved by molecular or morphological analyses. The latter tend to be confounded by
10296-555: Was entitled " Systema Naturae " ("the System of Nature"), implying that he, at least, believed that it was more than an "artificial system"). Later came systems based on a more complete consideration of the characteristics of taxa, referred to as "natural systems", such as those of de Jussieu (1789), de Candolle (1813) and Bentham and Hooker (1862–1863). These classifications described empirical patterns and were pre- evolutionary in thinking. The publication of Charles Darwin 's On
10400-471: Was formerly thought to belong to Spheniscidae; however, re-examination of the holotype in 1943 resulted in the genus being placed in Accipitridae . Further examination in 1980 resulted in placement as Aves incertae sedis . Taxonomy (biology) In biology , taxonomy (from Ancient Greek τάξις ( taxis ) 'arrangement' and -νομία ( -nomia ) ' method ')
10504-615: Was popularized in the Anglophone world by the speculative but widely read Vestiges of the Natural History of Creation , published anonymously by Robert Chambers in 1844. With Darwin's theory, a general acceptance quickly appeared that a classification should reflect the Darwinian principle of common descent . Tree of life representations became popular in scientific works, with known fossil groups incorporated. One of
10608-606: Was probably the heaviest, weighing 80 kilograms (180 lb) or more. Both were found on New Zealand, the former also in the Antarctic farther eastwards. Traditionally, most extinct species of penguins, giant or small, had been placed in the paraphyletic subfamily called Palaeeudyptinae . More recently, with new taxa being discovered and placed in the phylogeny if possible, it is becoming accepted that there were at least two major extinct lineages. One or two closely related ones occurred in Patagonia , and at least one other—which
10712-543: Was the Italian physician Andrea Cesalpino (1519–1603), who has been called "the first taxonomist". His magnum opus De Plantis came out in 1583, and described more than 1500 plant species. Two large plant families that he first recognized are in use: the Asteraceae and Brassicaceae . In the 17th century John Ray ( England , 1627–1705) wrote many important taxonomic works. Arguably his greatest accomplishment
10816-429: Was the text he used as a young student. The Swedish botanist Carl Linnaeus (1707–1778) ushered in a new era of taxonomy. With his major works Systema Naturae 1st Edition in 1735, Species Plantarum in 1753, and Systema Naturae 10th Edition , he revolutionized modern taxonomy. His works implemented a standardized binomial naming system for animal and plant species, which proved to be an elegant solution to
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