Mammalia is a class of animal within the Phylum Chordata. Mammal classification has been several iterations since Carl Linnaeus initially defined the class. No classification system is accepted, McKenna & Bell and Wilson & Reader provide useful recent compendiums. Competing ideas about the relationships of mammal orders do persist and are currently in development, most significantly in recent years, cladistic thinking has led to an effort to ensure that all taxonomic designations represent monophyletic groups. The field has seen a recent surge in interest and modification due to the results of molecular phylogenetics. Though field work gradually made Simpsons classification outdated, it remained the closest thing to a classification of mammals. See list of mammals and list of monotremes and marsupials for more detailed information on mammal genera. Molecular studies by molecular systematists, based on DNA analysis, in the early 21st century have revealed new relationships among mammal families, the relationships between these three lineages is contentious, and all three have been proposed as basal in different hypotheses.
The first divergence was that of the Afrotheria 110–100 million years ago, the Afrotheria proceeded to evolve and diversify in the isolation of the African-Arabian continent. The Xenarthra, isolated in South America, diverged from the Boreoeutheria approximately 100–95 mya, the Boreoeutheria split into the Laurasiatheria and Euarchontoglires between 95 and 85 mya, both of these groups evolved on the northern continent of Laurasia. With the exception of bats and murine rodents, no land mammals reached Australasia until the first human settlers arrived approximately 50,000 years ago. It should however be noted that these results are still controversial mainly because they are not reflected by morphological data. It is important to note that fossil taxa are not and, in most cases cannot, the following taxonomy of extant and recently extinct mammals is taken from Vaughan et al. This approach emphasizes an initial split between egg-laying prototherians and live-bearing therians, the therians are further divided into the marsupial Metatheria and the placental Eutheria.
No attempt is made in this classification to further distinguish among the orders within these subclasses and infraclasses and this system makes no note of the position of entirely fossil groups. In this and taxonomies, families are listed under the order to which they belong. More detailed relationships among families is presented in the article of each order, McKenna and Susan K. Bell, which has resulted in the McKenna/Bell classification. The authors worked together as paleontologists at the American Museum of Natural History, McKenna inherited the project from Simpson and, with Bell, constructed a completely updated hierarchical system, covering living and extinct taxa that reflects the historical genealogy of Mammalia
Darwins fox or Darwins Zorro is a small Endangered canine from the genus Lycalopex. It is known as the Zorro Chilote or Zorro de Darwin in Spanish and lives on Nahuelbuta National Park, Darwins fox was first collected from San Pedro Island off the coast of Chile by the naturalist Charles Darwin in 1834. In 2012 and 2013 the presence of the Darwins fox at Oncol Park, Alerce Costero National Park, pseudalopex is a South American genus of canine distantly related to wolves and is technically not a fox. He said it was a species, indicating that it was distinct from the species that occur on the mainland. Later, Darwins fox was classified as a subspecies of the latter, Darwins fox does not interbreed with the other Lycalopex species, only lives in forests, and is smaller and darker-colored than the other species. In 1990 a small population of Darwins fox was found on the mainland in the forested Nahuelbuta National Park, according to Yahnke the present restricted range is a relic of a much wider former range.
Zoologists noted the distinctiveness in the niche, appearance. In the late Pleistocene, Chiloé Island was connected to mainland Chile by a land bridge, the land bridge was severed about 15,000 years ago when the sea level rose following the last glaciation. This created two isolated populations of Darwins fox, Darwins fox has a vast diet. In dense forests, where it exists, the hunt for mammals, beetles. Sometimes it selects fruits and berries and amphibians to a lesser degree are consumed. It sometimes eats carrion, but it mostly eats live animals and this makes it mostly an omnivore, sometimes a scavenger. Darwins fox is believed to be a forest obligate species found only in southern temperate rainforests. They only occur in areas of primary forest on Chiloé and on the mainland and they are most active at twilight and before sunrise. In contrast to other Lycalopex species, Darwins fox prefers open spaces, the population of Chiloé has about 200 individuals, and Nahuelbuta on the mainland contains about 50 individuals.
The total population size is about 250 mature individuals with at least 90% of the population occurring in one subspopulation, current estimates of the total population are still low, with an estimated minimum 227 individuals on the mainland and 412 on Chiloé Island. Persecution by people who think that the foxes attack domestic fowls, though they pose little threat, is a potential problem
The Ethiopian wolf is a canid native to the Ethiopian Highlands. It is similar to the coyote in size and build, and is distinguished by its long and narrow skull, unlike most large canids, which are widespread, generalist feeders, the Ethiopian wolf is a highly specialised feeder of Afroalpine rodents with very specific habitat requirements. It is one of the worlds rarest canids, and Africas most endangered carnivore, the Ethiopian wolf is listed as endangered by the IUCN, on account of its small numbers and fragmented range. Threats include increasing pressure from expanding populations, resulting in habitat degradation through overgrazing. Its conservation is headed by Oxford Universitys Ethiopian Wolf Conservation Programme, alternative English names for the Ethiopian wolf include Abyssinian wolf, Simien fox, Simien jackal, Ethiopian jackal, red fox, red jackal, Abyssinian dog and cuberow. Since then, it was heard of in Europe up until the early 20th century. The Ethiopian wolf was recognised as requiring protection in 1938, the first in-depth studies on the species occurred in the 1980s with the onset of the American-sponsored Bale Mountains Research Project.
In response, the IUCN reclassified the species from endangered to endangered in 1994. The IUCN/SSC Canid Specialist Group advocated a three-front strategy of education, wolf population monitoring, the establishment of the Ethiopian Wolf Conservation Programme in Bale soon followed in 1995 by Oxford University, in conjunction with the Ethiopian Wildlife Conservation Authority. Soon after, a wolf population was discovered in the Central Highlands. Wolves were recorded in the Arsi Mountains since the early 20th century, the status of the Ethiopian wolf was reassessed in the late 1990s, following improvements in travel conditions into northern Ethiopia. The surveys taken revealed local extinctions in Mount Choqa and this revelation stressed the importance of the Bale Mountains wolf populations for the species long-term survival, as well as the need to protect other surviving populations. Although fossil records exist of wolf-like canids from Late Pleistocene Eurasia, see further, Canis evolution Due to the high density of rodents in their new Afroalpine habitat, the ancestors of the Ethiopian wolf gradually developed into specialised rodent hunters.
This specialisation is reflected in the skull morphology, with its very elongated head, long jaw. During this period, the species likely attained its highest abundance and this changed about 15,000 years ago with the onset of the current interglacial, which caused the species Afroalpine habitat to fragment, thus isolating Ethiopian wolf populations from each other. The Ethiopian wolf is one of five Canis species present in Africa, and is distinguishable from jackals by its larger size, relatively longer legs, distinct reddish coat. John Edward Gray and Glover Morrill Allen originally classified the species under a genus, Simenia. Juliet Clutton-Brock refuted the separate genus in favour of placing the species in the genus Canis, further studies on RAD sequences found instances of Ethiopian wolves hybridizing with African golden wolves
The Iberian lynx is a wild cat species native to the Iberian Peninsula in southwestern Europe that is listed as Endangered on the IUCN Red List. It preys almost exclusively on the European rabbit, by the turn of the 21st century, the Iberian lynx was on the verge of extinction, as only about 100 individuals survived in two isolated subpopulations in Andalusia. As an attempt to save species from extinction, an EU LIFE project is underway that includes habitat preservation, lynx population monitoring. Formerly considered a subspecies of the Eurasian lynx, the Iberian lynx is now classified as a separate species, both species occurred together in Central Europe in the Pleistocene and evolved as distinct species in the Late Pleistocene. The Iberian lynx is thought to have evolved from Lynx issiodorensis, the Iberian lynx has a bright yellowish to tawny colored spotted and short fur, a short body, long legs, a short tail, a small head with tufted ears and facial whiskers, called a ruff. Head and body length of males is 74.7 to 82 cm with a 12.5 to 16 cm long tail, males are larger than females who have a head-to-body-length of 68.2 to 77.5 cm and weigh 9.2 to 10 kg.
The spot pattern of the fur varies from uniformly and densely distributed small spots to more elongate spots arranged in lines that decrease in size from the back towards the sides, the Iberian lynx was once present throughout the Iberian Peninsula and southern France. In the 1950s, the population extended from the Mediterranean to Galicia and parts of northern Portugal. Populations declined from 15 subpopulations in the 1940s to only 2 subpopulations in the early 1990s, most noticeably in Montes de Toledo, before 1973, it was present in Sierra de Gata, Montes de Toledo, eastern Sierra Morena, Sierra de Relumbrar and Doñana coastal plains. Between the early 1960s and 2000, it has lost about 80% of its former range and it is now restricted to very limited areas in southern Spain, with breeding only confirmed in Sierra Morena and Doñana coastal plains. The Iberian lynx prefers heterogeneous environments of open grassland mixed with dense shrubs such as tree and juniper. It is now restricted to mountainous areas.
The Iberian lynx preys foremost on the European rabbit for the bulk of its diet, supplemented by red-legged partridge, rodents and it sometimes preys on young fallow deer, roe deer and ducks. A male requires one rabbit per day while a female raising kittens will eat three per day, there were two major outbreaks of the latter in 2011 and 2012. Recovery has occurred in some areas — in 2013, rabbit overpopulation was reported south of Córdoba, causing damage to transport infrastructure and farms. In December 2013, however, it was reported that officials were concerned about the spread of a new strain of the hemorraghic disease. Sierra Morenas rabbit population was worst affected, falling from an average of three per hectare to less than one — below the required level of 1.5 to two per hectare. Forced to travel distances for food, the lynx became more susceptible to death in road accidents
The giant otter or giant river otter is a South American carnivorous mammal. It is the longest member of the Mustelidae, or weasel family, atypical of mustelids, the giant otter is a social species, with family groups typically supporting three to eight members. The groups are centered on a dominant breeding pair and are cohesive and cooperative. Although generally peaceful, the species is territorial, and aggression has been observed between groups, the giant otter is diurnal, being active exclusively during daylight hours. It is the noisiest otter species, and distinct vocalizations have been documented that indicate alarm, the giant otter ranges across north-central South America, it lives mostly in and along the Amazon River and in the Pantanal. Its distribution has been reduced and is now discontinuous. Decades of poaching for its velvety pelt, peaking in the 1950s and 1960s, the species was listed as endangered in 1999 and wild population estimates are typically below 5,000. The Guianas are one of the last real strongholds for the species and it is one of the most endangered mammal species in the neotropics.
Habitat degradation and loss is the greatest current threat, the giant otter is rare in captivity, in 2003, only 60 animals were being held. The giant otter shows a variety of adaptations suitable to a lifestyle, including exceptionally dense fur, a wing-like tail. The species prefers freshwater rivers and streams, which are seasonally flooded. It constructs extensive campsites close to feeding areas, clearing large amounts of vegetation, the giant otter subsists almost exclusively on a diet of fish, particularly characins and catfish, but may eat crabs, turtles and small caiman. It has no natural predators other than humans, although it must compete with other species, including the neotropical otter and caiman species. The giant otter has a handful of other names, in Brazil it is known as ariranha, from the Tupí word ariraña, meaning water jaguar. All three names are in use in South America, with a number of regional variations, giant otter translates literally as nutria gigante and lontra gigante in Spanish and Portuguese, respectively.
Among the Achuar people, they are known as wankanim, the genus name, Pteronura, is derived from the Ancient Greek words pteron/πτερον and ura/ουρά, a reference to its distinctive, wing-like tail. The otters form the Lutrinae subfamily within the mustelids and the giant otter is the member of the genus Pteronura. Two subspecies are recognized by the canonical Mammal Species of the World, P. b. brasiliensis
The IUCN notes the importance of re-evaluating near-threatened taxa at appropriate intervals. The rationale used for near-threatened taxa usually includes the criteria of vulnerable which are plausible or nearly met, the 402 conservation-dependent taxa may be considered near-threatened. Prior to 2001, the IUCN used the version 2.3 Categories and Criteria, with this category system, Near Threatened and Conservation Dependent were both subcategories of the category Lower Risk. IUCN Red List near threatened species, ordered by taxonomic rank, category, IUCN Red List near threatened species, ordered alphabetically
Saimaa ringed seal
The Saimaa ringed seal is a subspecies of ringed seal. They are among the most endangered seals in the world, having a population of only about 320 individuals. The only existing population of seals is found in Lake Saimaa. The population is descended from ringed seals that were separated from the rest when the land rose after the last ice age and this seal, along with the Ladoga seal and the Baikal seal, is one of the few living freshwater seals. An adult Saimaa ringed seal is between 85 and 160 centimetres in length and weighs between 50 and 90 kilograms, males usually being larger than females and they are coloured dark gray, with a gray-black dorsal with circular white rings. The Saimaa ringed seal is darker in color than other ringed seals, Saimaa ringed seals become mature between the ages of 4 and 6 on average. Their pregnancy rate is between 80 and 95 percent, ringed seals gestation lasts 11 months. Their pups are between 55 and 65 centimetres, and 4 to 5 kilograms at birth, the Saimaa ringed seals longevity is just over 20 years.
The Saimaa ringed seal has been protected since 1955, in 1983, the population was between 100 and 150 seals. In 2005, it was about 270, but as a result of two breeding seasons,2006 and 2007, the number dropped down to 260. In 2013 the population was estimated at just over 300 and the numbers were in a slight growth. The number of breeding-aged females was 87 and it is thought that the immediate threat of extinction would be alleviated if the population grew to over 400 individuals. It is listed as endangered by the U. S. government under the Endangered Species Act, in spring 2016,79 pups were found, four of which were dead. In order to protect the Saimaa ringed seal, there are voluntary restrictions in a part of their living areas. The most important form of restriction is a ban for fishing nets from April 15 to the end of June in about 15% of the lake, bycatch mortality has, remained high with estimated mortality of 20–30 seals annually, most of them pups of the same year. In 2016, one act and mutual agreements between authorities and owners of fishing waters replace earlier two acts, the fishing co-operatives get 1.7 euros per hectare to monitor that fishing limitations are followed.
Net fishing is forbidden between 15th April and end of June in certain areas, which have drawn at 5 km radius from nesting sites. Breeding success of Saimaa ringed seal depends on sufficient ice and snow cover, the loss of snow and ice caused by the ongoing climate change poses a direct threat to them
Such a name is called a binomial name, a binomen, binominal name or a scientific name, more informally it is called a Latin name. The first part of the name identifies the genus to which the species belongs, for example, humans belong to the genus Homo and within this genus to the species Homo sapiens. The formal introduction of system of naming species is credited to Carl Linnaeus. But Gaspard Bauhin, in as early as 1623, had introduced in his book Pinax theatri botanici many names of genera that were adopted by Linnaeus. Although the general principles underlying binomial nomenclature are common to these two codes, there are differences, both in the terminology they use and in their precise rules. Similarly, both parts are italicized when a binomial name occurs in normal text, thus the binomial name of the annual phlox is now written as Phlox drummondii. In scientific works, the authority for a name is usually given, at least when it is first mentioned. In zoology Patella vulgata Linnaeus,1758, the original name given by Linnaeus was Fringilla domestica, the parentheses indicate that the species is now considered to belong in a different genus.
The ICZN does not require that the name of the person who changed the genus be given, nor the date on which the change was made, in botany Amaranthus retroflexus L. – L. is the standard abbreviation used in botany for Linnaeus. – Linnaeus first named this bluebell species Scilla italica, Rothmaler transferred it to the genus Hyacinthoides, the ICN does not require that the dates of either publication be specified. Prior to the adoption of the binomial system of naming species. Together they formed a system of polynomial nomenclature and these names had two separate functions. First, to designate or label the species, and second, to be a diagnosis or description, such polynomial names may sometimes look like binomials, but are significantly different. For example, Gerards herbal describes various kinds of spiderwort, The first is called Phalangium ramosum, Branched Spiderwort, is aptly termed Phalangium Ephemerum Virginianum, Soon-Fading Spiderwort of Virginia. The Latin phrases are short descriptions, rather than identifying labels, the Bauhins, in particular Caspar Bauhin, took some important steps towards the binomial system, by pruning the Latin descriptions, in many cases to two words.
The adoption by biologists of a system of binomial nomenclature is due to Swedish botanist and physician Carl von Linné. It was in his 1753 Species Plantarum that he first began using a one-word trivial name together with a generic name in a system of binomial nomenclature. This trivial name is what is now known as an epithet or specific name
Mediterranean monk seal
The Mediterranean monk seal is a pinniped belonging to the family Phocidae. It is believed to be the worlds rarest pinniped species and this species of seal grows from approximately 80 centimetres long at birth up to an average of 2.4 metres as adults. Males weigh an average of 320 kilograms and females weigh 300 kilograms and they are thought to live up to 45 years old, the average life span is thought to be 20 to 25 years old and reproductive maturity is reached at around age four. The monk seals pups are about 1 metre long and weigh around 15–18 kilograms, their skin being covered by 1–1.5 centimeter-long, on their bellies, there is a white stripe, which differs in color and shape between the two sexes. In females the stripe is usually rectangular in shape whereas in males it is usually butterfly shaped and this hair is replaced after six to eight weeks by the usual short hair adults carry. Pregnant Mediterranean monk seals typically use inaccessible undersea caves while giving birth, there are eight pairs of teeth in both jaws.
Believed to have the shortest hair of any pinniped, the Mediterranean monk seal fur is black or brown to grey, with a paler belly. The snout is broad and flat, with very pronounced, long nostrils that face upward, unlike their Hawaiian relative. The flippers are short, with small slender claws. Monk seals have two pairs of abdominal teats, unlike most other pinnipeds. Very little is known of this seals reproduction, scientists have suggested that they are polygynous, with males being very territorial where they mate with females. Although there is no breeding season since births take place year round and this is the time when caves are prone to wash out due to high surf or storm surge, which causes high mortality rates among monk seal pups, especially at the key Cabo Blanco colony. According to the IUCN species factsheet, pup survival is low, survival of pups born from September to January is 29%. This very low rate is associated with mortality caused by severe storms, and high swells and tides.
Pups born during the rest of the year had a rate of 71%. Pups make first contact with the two weeks after their birth and are weaned at around 18 weeks of age, females caring for pups will go off to feed for an average of nine hours. Most individuals are believed to reach maturity at four years of age, the gestation period lasts close to a year. However, it is believed to be common among monk seals of the Cabo Blanco colony to have a period lasting slightly longer than a year
The black-footed ferret, known as the American polecat or prairie dog hunter, is a species of mustelid native to central North America. It is listed as endangered by the IUCN, because of its very small, first discovered by Audubon and Bachman in 1851, the species declined throughout the 20th century, primarily as a result of decreases in prairie dog populations and sylvatic plague. It was declared extinct in 1979 until Lucille Hoggs dog brought a dead black-footed ferret to her door in Meeteetse and that remnant population of a few dozen ferrets lasted there until the animals were considered extinct in the wild in 1987. However, a breeding program launched by the United States Fish and Wildlife Service resulted in its reintroduction into eight western states. There are now over 1,000 mature, wild-born individuals in the wild across 18 populations, with four self-sustaining populations in South Dakota and Wyoming. The black-footed ferret is roughly the size of a mink, in contrast, differences between the black-footed ferret and the steppe polecat of Asia are slight, to the point where the two species were once thought to be conspecific.
The only noticeable differences between the black-footed ferret and the steppe polecat are the much shorter and coarser fur, larger ears. It is largely nocturnal and solitary, except when breeding or raising litters, up to 91% of its diet is composed of prairie dogs. Like its close cousin, the Asian steppe polecat, the ferret represents a more progressive form than the European polecat in the direction of carnivory. The black-footed ferrets most likely ancestor was Mustela stromeri, which originated in Europe during the Middle Pleistocene, molecular evidence indicates that the steppe polecat and black-footed ferret diverged from Mustela stromeri sometime between 500,000 and 2,000,000 years ago, perhaps in Beringia. The species appeared in the Great Basin and the Rockies by 750,000 years ago, the oldest recorded fossil find originates from Cathedral Cave, White Pine County and dates back to 750, 000–950,000 years ago. Prairie dog fossils have found in six sites where ferrets are yielded. This suggests that the ferret and prairie dogs did not historically have an obligate predator-prey relationship.
The species has always been rare, and the modern black-footed ferret represents a relic population. The earliest reported occurrence of the species is from a late Illinoian deposit in Clay County, fossils have been found in Alaska dating from the Pleistocene. The black-footed ferret has a body and a blunt head. The forehead is arched and broad, and the muzzle is short and it has few whiskers, and its ears are triangular, short and broad at the base. The neck is long and the short and stout
Julian Huxley invented the term in his 1942 book, The Modern Synthesis. The modern synthesis solved difficulties and confusions caused by the specialisation, at its heart was the question of whether Mendelian genetics could be reconciled with gradual evolution by means of natural selection. A second issue was whether the changes of macroevolution seen by palaeontologists could be explained by changes seen in the microevolution of local populations. The synthesis included evidence from geneticists who studied populations in the field and these studies were crucial to evolutionary theory. The synthesis drew together ideas from several branches of biology which had separated, particularly genetics, systematics, botany. The modern synthesis of the early 20th century bridged the gap between the work of geneticists and naturalists, and paleontologists. It states that, All evolutionary phenomena can be explained in a way consistent with known genetic mechanisms, Evolution is gradual, small genetic changes regulated by natural selection accumulate over long periods.
Discontinuities amongst species are explained as originating gradually through geographical separation and extinction and this theory contrasts with the saltation theory of William Bateson. Natural selection is by far the main mechanism of change, even slight advantages are important when continued, the object of selection is the phenotype in its surrounding environment. The role of genetic drift is equivocal, though strongly supported initially by Dobzhansky, it was downgraded as results from ecological genetics were obtained. Thinking in terms of populations, rather than individuals, is primary, in palaeontology, the ability to explain historical observations by extrapolation from microevolution to macroevolution is proposed. Historical contingency means explanations at different levels may exist, gradualism does not mean constant rate of change. The idea that speciation occurs after populations are reproductively isolated has been much debated, in plants, polyploidy must be included in any view of speciation.
Formulations such as evolution consists primarily of changes in the frequencies of alleles between one generation and another were proposed rather later. The traditional view is that biology played little part in the synthesis. In the 19th and early 20th centuries, variations of Lamarckism, also, Darwin did not offer a precise explanation of how new species arise. Weismann and Wallace rejected the Lamarckian idea of inheritance of acquired characteristics, weismann was translated into English, and though he was influential, it took many years for the full significance of his work to be appreciated. Gregor Mendels work was re-discovered by Hugo de Vries and Carl Correns in 1900, news of this reached William Bateson in England, who reported on the paper during a presentation to the Royal Horticultural Society in May 1900
The leopard cat is a small wild cat native to South and East Asia. Since 2002 it has been assessed as Least Concern on the IUCN Red List as it is widely distributed but threatened by habitat loss, Leopard cat subspecies differ widely in fur colour, tail length, skull shape and size of carnassials. Archaeological evidence from China indicates that the cat was the first cat species to be domesticated. A leopard cat is about the size of a domestic cat and its small head is marked with two prominent dark stripes and a short and narrow white muzzle. There are two stripes running from the eyes to the ears, and smaller white streaks running from the eyes to the nose. The backs of its long and rounded ears are black with central white spots. Body and limbs are marked with spots of varying size and color. The tail is half the size of its head-body length and is spotted with a few indistinct rings near the black tip. The background color of the fur is tawny, with a white chest. However, in their range, they vary so much in coloration and size of spots as well as in body size.
The fur color is brown in the southern populations. The black markings may be spotted, rosetted, or may even form dotted streaks, depending on subspecies. In the tropics, leopard cats weigh 0.55 to 3.8 kg, have lengths of 38.8 to 66 cm. In northern China and Siberia, they weigh up to 7.1 kg, shoulder height is about 41 cm. Leopard cats in the Sundaic region are darker, have smaller spots, Leopard cats are the most widely distributed Asian small cats. They live in evergreen rainforests and plantations at sea level. They are able to tolerate human-modified landscapes with vegetation cover to some degree, in 2009, a leopard cat was camera trapped in Nepals Makalu-Barun National Park at an altitude of 3,254 m. At least six individuals inhabit the area, which is dominated by associations of rhododendron, oak