37-703: Golden moles are small insectivorous burrowing mammals endemic to Sub-Saharan Africa . They comprise the family Chrysochloridae (the only family in the suborder Chrysochloridea ) and as such they are taxonomically distinct from the true moles , family Talpidae , and other mole -like families, all of which, to various degrees, they resemble as a result of evolutionary convergence . There are 21 species. Some (e.g., Chrysochloris asiatica , Amblysomus hottentotus ) are relatively common, whereas others (e.g., species of Chrysospalax , Cryptochloris , Neamblysomus ) are rare and endangered. Despite their extreme evolutionary convergence with moles, their closest relatives are
74-510: A torpor when resting or during cold weather enables them to conserve energy and reduce urgent requirements for food. Similarly, they have developed particularly efficient kidneys, and some species do not need to drink water at all. They tend to drown if they fall into water. Chrysochloridae are subterranean, afrotherian mammals endemic to sub-Saharan Africa, and most of which are recorded from South Africa in particular. Other regions include Lake Victoria , Western Cape , and Namibia. They live in
111-894: A major role in the Neolithic Revolution , and resulted in farming replacing hunting and gathering as the primary source of food for humans. This led to a major restructuring of human societies from nomadic to sedentary, with more co-operation among larger and larger groups, and ultimately the development of the first civilizations . Domesticated mammals provided, and continue to provide, power for transport and agriculture, as well as food ( meat and dairy products ), fur , and leather . Mammals are also hunted and raced for sport, kept as pets and working animals of various types, and are used as model organisms in science. Mammals have been depicted in art since Paleolithic times, and appear in literature, film, mythology, and religion. Decline in numbers and extinction of many mammals
148-447: A number of features, varying by species, seldom seen elsewhere among living mammals, including three forearm long-bones, hyoid - mandible articulation, and a hypertrophied malleus . Some species have hypertrophied (enlarged) middle ear ossicles , in particular the malleus. These animals have the largest malleus relative to body size of any animal. This morphology may be adapted for the detection of seismic signals. In this respect there
185-497: A variety of environments; forest, swamps, deserts, or mountainous terrain. Chrysospalax species tend to forage above ground in leaf litter in forests or in meadows. Eremitalpa species such as Grant's golden mole live in the sandy Namib desert , where they cannot form tunnels because the sand collapses. Instead during the day, when they must seek shelter, they "swim" through the loose sand, using their broad claws to paddle, and dive down some 50 centimetres (20 in) to where it
222-432: Is a golden mole species. It is the only member of the genus Eremitalpa . Like all other golden moles, the build of these animals is similar to the moles , though they are not closely related, and are adapted to a life of digging. The front extremities are remodeled to digging claws; in contrast to most other species of its family, they have three claws each. The tail is physically not visible, there are no auricles,
259-537: Is bearably cool. There they enter a state of torpor , thus conserving energy. At night they emerge to forage on the surface rather than wasting energy shifting sand. Their main prey are termites that live under isolated grass clumps, and they might travel for 6 kilometres (3.7 mi) a night in search of food. They seek promising clumps by listening for wind-rustled grass-root stresses and termites' head-banging alarm signals, neither of which can be heard easily above ground, so they stop periodically and dip their heads under
296-444: Is dry areas, mostly sandy deserts. In contrast to many other golden moles, Grant's golden mole rarely builds lasting tunnels. It "swims" through the sand just under or on the surface while searching for food. It is mainly a nocturnal animal , resting by day in small caves beneath sheltering plants. It is a solitary animal, with stomping grounds averaging 4.6 ha . When foraging at night, the animal will alternate between moving over
333-572: Is primarily driven by human poaching and habitat destruction , primarily deforestation . Over 70% of mammal species are in the orders Rodentia , Chiroptera , and Eulipotyphla . Mammal classification has been through several revisions since Carl Linnaeus initially defined the class, and at present , no classification system is universally accepted. McKenna & Bell (1997) and Wilson & Reeder (2005) provide useful recent compendiums. Simpson (1945) provides systematics of mammal origins and relationships that had been taught universally until
370-664: Is some apparent convergent evolution to burrowing reptiles in the family Amphisbaenidae . Females give birth to one to three hairless young in a grass-lined nest within the burrow system. Breeding occurs throughout the year. The adults are solitary, and their burrowing territory may be aggressively defended from intruders, especially where resources are relatively scarce. Of the 21 species of golden mole, no fewer than 11 are threatened with extinction. The primary cause being human-induced habitat loss. Additionally sand mining , poor agricultural practices, and predation by domestic cats and dogs are causes of population decline. The taxonomy of
407-526: The Carboniferous Period over 300 million years ago. Around 6,400 extant species of mammals have been described and divided into 27 orders . The largest orders of mammals, by number of species , are the rodents , bats , and Eulipotyphla (including hedgehogs , moles and shrews ). The next three are the primates (including humans , monkeys and lemurs ), the even-toed ungulates (including pigs , camels , and whales ), and
SECTION 10
#1732797622048444-530: The Carnivora (including cats , dogs , and seals ). Mammals are the only living members of Synapsida ; this clade , together with Sauropsida (reptiles and birds), constitutes the larger Amniota clade. Early synapsids are referred to as " pelycosaurs ." The more advanced therapsids became dominant during the Guadalupian . Mammals originated from cynodonts , an advanced group of therapsids, during
481-473: The Cretaceous . The relationships between these three lineages is contentious, and all three possible hypotheses have been proposed with respect to which group is basal . These hypotheses are Atlantogenata (basal Boreoeutheria), Epitheria (basal Xenarthra) and Exafroplacentalia (basal Afrotheria). Boreoeutheria in turn contains two major lineages— Euarchontoglires and Laurasiatheria . Estimates for
518-564: The International Union for Conservation of Nature (IUCN) completed a five-year Global Mammal Assessment for its IUCN Red List , which counted 5,488 species. According to research published in the Journal of Mammalogy in 2018, the number of recognized mammal species is 6,495, including 96 recently extinct. The word " mammal " is modern, from the scientific name Mammalia coined by Carl Linnaeus in 1758, derived from
555-556: The Latin mamma ("teat, pap"). In an influential 1988 paper, Timothy Rowe defined Mammalia phylogenetically as the crown group of mammals, the clade consisting of the most recent common ancestor of living monotremes ( echidnas and platypuses ) and therian mammals ( marsupials and placentals ) and all descendants of that ancestor. Since this ancestor lived in the Jurassic period, Rowe's definition excludes all animals from
592-550: The biological classification scheme used, are the primates : apes , monkeys , and lemurs ; the Cetartiodactyla : whales and even-toed ungulates ; and the Carnivora which includes cats , dogs , weasels , bears , seals , and allies. According to Mammal Species of the World , 5,416 species were identified in 2006. These were grouped into 1,229 genera , 153 families and 29 orders. In 2008,
629-478: The marsupial / placental divide notwithstanding, some argued that they were related. Considerations that influenced the debate might have included the view that the Chrysochloridae are very primitive placentals and the fact that they have many mole-like specializations similar to specializations in marsupial moles. The rhinarium is a greatly enlarged, dry leathery pad that protects their nostrils while
666-409: The otter shrews and tenrecs . They are more distantly related to other insectivorous African mammals such as aardvarks and elephant shrews , and even more distantly related to elephants and sirenians . Like most burrowing mammals with similar habits, the Chrysochloridae have short legs with powerful digging claws, very dense fur that repels dirt and moisture, and toughened skin, particularly on
703-490: The Chrysochloridae is undergoing a review in the light of new genetic information. They have traditionally been listed with the shrews , hedgehogs and a grab-bag of small, difficult-to-place creatures as part of the order Insectivora . Some authorities retain this classification, at least for the time being. Others group the golden moles with the tenrecs in a new order, which is sometimes known as Tenrecomorpha , while others call it Afrosoricida and reserve Tenrecomorpha for
740-596: The Late Triassic to Early Jurassic . Mammals achieved their modern diversity in the Paleogene and Neogene periods of the Cenozoic era, after the extinction of non-avian dinosaurs , and have been the dominant terrestrial animal group from 66 million years ago to the present. The basic mammalian body type is quadrupedal , with most mammals using four limbs for terrestrial locomotion ; but in some,
777-430: The animal digs. In this respect, too, they resemble the marsupial moles. Some authors claim their primary sense is of touch , and they are particularly sensitive to vibrations, which may indicate approaching danger. Note below, however, the observations on the malleus in the middle ear. The species range in size from about 8 centimetres (3.1 in) to about 20 centimetres (7.9 in). They have muscular shoulders and
SECTION 20
#1732797622048814-812: The clade originating with the last common ancestor of Sinoconodon and living mammals. The earliest-known synapsid satisfying Kemp's definitions is Tikitherium , dated 225 Ma , so the appearance of mammals in this broader sense can be given this Late Triassic date. However, this animal may have actually evolved during the Neogene. As of the early 21st century, molecular studies based on DNA analysis have suggested new relationships among mammal families. Most of these findings have been independently validated by retrotransposon presence/absence data . Classification systems based on molecular studies reveal three major groups or lineages of placental mammals— Afrotheria , Xenarthra and Boreoeutheria —which diverged in
851-444: The closest thing to an official classification of mammals, despite its known issues. Most mammals, including the six most species-rich orders , belong to the placental group. The three largest orders in numbers of species are Rodentia : mice , rats , porcupines , beavers , capybaras , and other gnawing mammals; Chiroptera : bats; and Eulipotyphla : shrews , moles , and solenodons . The next three biggest orders, depending on
888-1413: The divergence times between these three placental groups range from 105 to 120 million years ago, depending on the type of DNA used (such as nuclear or mitochondrial ) and varying interpretations of paleogeographic data. Monotremata Marsupialia Xenarthra Afrotheria Glires Euarchonta [REDACTED] Eulipotyphla Chiroptera Pholidota Carnivora [REDACTED] Perissodactyla [REDACTED] Artiodactyla [REDACTED] Monotremata [REDACTED] Paucituberculata [REDACTED] Didelphimorphia [REDACTED] Microbiotheria Notoryctemorphia [REDACTED] Peramelemorphia [REDACTED] Dasyuromorphia [REDACTED] Diprotodontia [REDACTED] Cingulata [REDACTED] Pilosa [REDACTED] Hyracoidea [REDACTED] Sirenia [REDACTED] Proboscidea [REDACTED] Tubulidentata [REDACTED] Macroscelidea [REDACTED] Afrosoricida [REDACTED] Eulipotyphla [REDACTED] Chiroptera [REDACTED] Pholidota [REDACTED] Carnivora [REDACTED] Perissodactyla [REDACTED] Artiodactyla [REDACTED] Scandentia [REDACTED] Lagomorpha [REDACTED] Eremitalpa E. g. granti E. g. namibensis Grant's golden mole ( Eremitalpa granti ; colloquially also: dune shark )
925-585: The earlier Triassic , despite the fact that Triassic fossils in the Haramiyida have been referred to the Mammalia since the mid-19th century. If Mammalia is considered as the crown group, its origin can be roughly dated as the first known appearance of animals more closely related to some extant mammals than to others. Ambondro is more closely related to monotremes than to therian mammals while Amphilestes and Amphitherium are more closely related to
962-451: The end of the 20th century. However, since 1945, a large amount of new and more detailed information has gradually been found: The paleontological record has been recalibrated, and the intervening years have seen much debate and progress concerning the theoretical underpinnings of systematization itself, partly through the new concept of cladistics . Though fieldwork and lab work progressively outdated Simpson's classification, it remains
999-480: The eyes are covered with fur, and the mouth is bearing a leather-like pad, which also serves for digging. Grant's golden moles have long silky fur, which is colored gray on cubs and sandy on older animals. With a length of 7.5 to 9 cm (3.0 to 3.5 in) and a weight of 15 to 25 g (0.53 to 0.88 oz) it is the smallest member of its species. Grant's golden mole lives on the western coast of South Africa and in south western Namibia . Its natural habitat
1036-497: The family Tenrecidae. Mammal A mammal (from Latin mamma 'breast') is a vertebrate animal of the class Mammalia ( / m ə ˈ m eɪ l i . ə / ). Mammals are characterized by the presence of milk -producing mammary glands for feeding their young, a broad neocortex region of the brain, fur or hair , and three middle ear bones . These characteristics distinguish them from reptiles and birds , from which their ancestors diverged in
1073-419: The forelimbs are radically adapted for digging; all the toes on the forefeet have been reduced, except for a large, pick-like third claw on the third toe. In comparison to true moles, the fifth digit is absent and the first and fourth digits are vestigial. The adaptations of the hind feet are less dramatic: They retain all five toes and are webbed as an adaptation to efficient backward shoveling of soil loosened by
1110-611: The front claws. At one time, the Chrysochloridae were regarded as primitive . Supporting arguments of this included that they were thought to have originated in Gondwana , that they had a low resting metabolic rate, and that they could switch off thermoregulation when inactive. Like the tenrecs , they possess a cloaca , and males lack a scrotum . However, these points are no longer regarded as strongly suggestive of golden moles as undeveloped "reptilian mammals"; some are seen rather as adaptations to regional climatic conditions. Going into
1147-423: The head. The fur varies from black to pale yellow or grey, and has an iridescent sheen of green, blue, violet or copper when viewed in light. Their eyes are non-functional and covered with furred skin. The external ears are just tiny openings. In particular, golden moles bear a remarkable resemblance to the marsupial moles of Australia , family Notoryctidae , which they resemble so suggestively that at one time,
Golden mole - Misplaced Pages Continue
1184-451: The limbs are adapted for life at sea , in the air , in trees or underground . The bipeds have adapted to move using only the two lower limbs, while the rear limbs of cetaceans and the sea cows are mere internal vestiges . Mammals range in size from the 30–40 millimetres (1.2–1.6 in) bumblebee bat to the 30 metres (98 ft) blue whale —possibly the largest animal to have ever lived. Maximum lifespan varies from two years for
1221-415: The production of ultrasound , scent marking , alarm signals , singing , echolocation ; and, in the case of humans, complex language . Mammals can organize themselves into fission–fusion societies , harems , and hierarchies —but can also be solitary and territorial . Most mammals are polygynous , but some can be monogamous or polyandrous . Domestication of many types of mammals by humans played
1258-411: The sand to listen. Most other species construct both foraging superficial burrows and deeper permanent burrows for residence. Residential burrows are relatively complex in form and may penetrate as far as 1 metre (3 ft 3 in) below ground and include deep chambers for use for refuge, and other chambers as latrines. They push excavated soil up to the surface, as in mole-hills, or compact it into
1295-503: The shrew to 211 years for the bowhead whale . All modern mammals give birth to live young, except the five species of monotremes , which lay eggs. The most species-rich group is the viviparous placental mammals , so named for the temporary organ ( placenta ) used by offspring to draw nutrition from the mother during gestation . Most mammals are intelligent , with some possessing large brains, self-awareness , and tool use . Mammals can communicate and vocalize in several ways, including
1332-548: The therians; as fossils of all three genera are dated about 167 million years ago in the Middle Jurassic , this is a reasonable estimate for the appearance of the crown group. T. S. Kemp has provided a more traditional definition: " Synapsids that possess a dentary – squamosal jaw articulation and occlusion between upper and lower molars with a transverse component to the movement" or, equivalently in Kemp's view,
1369-472: The tunnel walls. They feed on small insects and earthworms or small vertebrates such as lizards or burrowing snakes. They depend on their sense of hearing to locate much of their prey, and the cochleas of a number of golden mole species have been found to be long and highly coiled, which may indicate a greater ecological dependence on low frequency auditory cues than seen in Talpid moles. Golden moles share
#47952