哺乳动物或哺乳类是对脊椎动物下哺乳纲（学名：Mammalia，出自拉丁语mamma，即“胸部”）动物的统称。与同属羊膜动物、在石炭紀（約30億年前）分化的爬蟲類、鳥類不同的是，哺乳类具有新皮质、毛皮、三個听小骨和乳腺，雌性还會用乳腺分泌乳汁餵養幼崽。目前，人们共发表了约 6400 个哺乳類物种，其中物种数量最多的目有囓齒目、翼手目和真盲缺目（刺猬、鼹鼠、鼩鼱等），多樣性略低於以上三目的有灵长目（包含人類在內的猿、猴等）、偶蹄目（鯨豚類和其他偶蹄目）和食肉目（猫、狗、海豹等）。
以支序學的角度來看，哺乳類是合弓綱中的唯一成員，而合弓綱和蜥形綱組合成了一個更大的演化支羊膜動物。合弓綱哺乳動物的先祖為楔齒龍類中的盤龍目，包含非哺乳類的異齒龍屬。在 30 億年前，石炭紀末期，合弓綱從蜥形綱中分化出來後，其中一個分支演化成了哺乳類，而蜥形綱則成為了現生的鳥類和爬蟲類。在二疊紀早期獸孔目出現之前，楔齒龍類的基群演化成了好幾支多樣性高的非哺乳類合弓綱，這些生物偶爾會被誤認為類似哺乳類的爬蟲類。現生的哺乳類起源於新生代的古近紀和新近紀，大約6600萬年前，也就是非鳥恐龍滅絕之後，且自出現以來便是陸生動物中最具優勢的類群。
自从卡尔·林奈首次将哺乳类分为一纲以来，哺乳动物的定义曾多次变动。目前，人们对哺乳动物的分类方式还没有明确的共识；最新有关方面的研究由麦肯纳与贝尔（1997年）和威尔森与里德尔（2005年）作出。喬治·蓋洛德·辛普森的“哺乳动物分类与分类原则”（AMNH Bulletin v. 85, 1945）从系統分類學上阐述了哺乳动物的起源、关系，他的理论直到20世纪末都还出现在各个教科书中。自辛普森发明了分类系统以来，化石记录已几经修正。分类系统理论本身也经多方讨论、发展壮大，在支序分類學出现后更是愈演愈烈。虽然实地考察中新发现的生物证据让辛普森的分类系统逐渐落伍，但他的分类方式依然是哺乳动物分类体系中最为权威的。
T·S·坎普（T. S. Kemp）曾提出过更为传统的定义：“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, the clade originating with the last common ancestor of 中國尖齒獸 and living mammals. The earliest known synapsid satisfying Kemp's definitions is Tikitherium, dated 2.25亿年前, so the appearance of mammals in this broader sense can be given this Late Triassic date.
In 1997, the mammals were comprehensively revised by Malcolm C. McKenna and Susan K. Bell, which has resulted in the McKenna/Bell classification. Their 1997 book, Classification of Mammals above the Species Level, is a comprehensive work on the systematics, relationships and occurrences of all mammal taxa, living and extinct, down through the rank of genus, though molecular genetic data challenge several of the higher level groupings. The authors worked together as paleontologists at the American Museum of Natural History, New York. 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.
- 原兽亚纲 Prototheria：
- 獸形亞綱 Theriiformes：現存的哺乳動物與其已滅絕的近親
- †异兽亚纲 Allotheria: multituberculates
- †真三尖齿兽目 Eutriconodonta: eutriconodonts
- 完獸亞綱 Holotheria：現存的哺乳動物與其已滅絕的近親
- 獸亞綱 Theria：現存的哺乳動物
- 有袋類 Marsupialia
- 胎盤動物 Placentalia
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 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 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.
- 非洲食蟲類 Afroinsectiphilia
- 近蹄類 Paenungulata
- 靈長總目 Euarchontoglires
- 勞亞獸總目 Laurasiatheria
哺乳動物的肺部呈海綿狀及蜂巢狀。Breathing is mainly achieved with the diaphragm, which divides the thorax from the abdominal cavity, forming a dome convex to the thorax. Contraction of the diaphragm flattens the dome, increasing the volume of the lung cavity. Air enters through the oral and nasal cavities, and travels through the larynx, trachea and bronchi, and expands the alveoli. Relaxing the diaphragm has the opposite effect, decreasing the volume of the lung cavity, causing air to be pushed out of the lungs. During exercise, the abdominal wall contracts, increasing pressure on the diaphragm, which forces air out quicker and more forcefully. The rib cage is able to expand and contract the chest cavity through the action of other respiratory muscles. Consequently, air is sucked into or expelled out of the lungs, always moving down its pressure gradient. This type of lung is known as a bellows lung due to its resemblance to blacksmith bellows.
The mammalian heart has four chambers, two upper atria, the receiving chambers, and two lower ventricles, the discharging chambers. The heart has four valves, which separate its chambers and ensures blood flows in the correct direction through the heart (preventing backflow). After gas exchange in the pulmonary capillaries (blood vessels in the lungs), oxygen-rich blood returns to the left atrium via one of the four pulmonary veins. Blood flows nearly continuously back into the atrium, which acts as the receiving chamber, and from here through an opening into the left ventricle. Most blood flows passively into the heart while both the atria and ventricles are relaxed, but toward the end of the ventricular relaxation period, the left atrium will contract, pumping blood into the ventricle. The heart also requires nutrients and oxygen found in blood like other muscles, and is supplied via coronary arteries.
The integumentary system (skin) is made up of three layers: the outermost epidermis, the dermis and the hypodermis. The epidermis is typically 10 to 30 cells thick; its main function is to provide a waterproof layer. Its outermost cells are constantly lost; its bottommost cells are constantly dividing and pushing upward. The middle layer, the dermis, is 15 to 40 times thicker than the epidermis. The dermis is made up of many components, such as bony structures and blood vessels. The hypodermis is made up of adipose tissue, which stores lipids and provides cushioning and insulation. The thickness of this layer varies widely from species to species;:97 marine mammals require a thick hypodermis (blubber) for insulation, and right whales have the thickest blubber at 20英寸（51厘米）. Although other animals have features such as whiskers, feathers, setae, or cilia that superficially resemble it, no animals other than mammals have hair. It is a definitive characteristic of the class. Though some mammals have very little, careful examination reveals the characteristic, often in obscure parts of their bodies.:61
Herbivores have developed a diverse range of physical structures to facilitate the consumption of plant material. To break up intact plant tissues, mammals have developed teeth structures that reflect their feeding preferences. For instance, frugivores (animals that feed primarily on fruit) and herbivores that feed on soft foliage have low-crowned teeth specialized for grinding foliage and seeds. Grazing animals that tend to eat hard, silica-rich grasses, have high-crowned teeth, which are capable of grinding tough plant tissues and do not wear down as quickly as low-crowned teeth. Most carnivorous mammals have carnassialiforme teeth (of varying length depending on diet), long canines and similar tooth replacement patterns.
The stomach of Artiodactyls is divided into four sections: the rumen, the reticulum, the omasum and the abomasum (only ruminants have a rumen). After the plant material is consumed, it is mixed with saliva in the rumen and reticulum and separates into solid and liquid material. The solids lump together to form a bolus (or cud), and is regurgitated. When the bolus enters the mouth, the fluid is squeezed out with the tongue and swallowed again. Ingested food passes to the rumen and reticulum where cellulytic microbes (bacteria, protozoa and fungi) produce cellulase, which is needed to break down the cellulose in plants. Perissodactyls, in contrast to the ruminants, store digested food that has left the stomach in an enlarged cecum, where it is fermented by bacteria. Carnivora have a simple stomach adapted to digest primarily meat, as compared to the elaborate digestive systems of herbivorous animals, which are necessary to break down tough, complex plant fibers. The caecum is either absent or short and simple, and the large intestine is not sacculated or much wider than the small intestine.
The mammalian excretory system involves many components. Like most other land animals, mammals are ureotelic, and convert ammonia into urea, which is done by the liver as part of the urea cycle. Bilirubin, a waste product derived from blood cells, is passed through bile and urine with the help of enzymes excreted by the liver. The passing of bilirubin via bile through the intestinal tract gives mammalian feces a distinctive brown coloration. Distinctive features of the mammalian kidney include the presence of the renal pelvis and renal pyramids, and of a clearly distinguishable cortex and medulla, which is due to the presence of elongated loops of Henle. Only the mammalian kidney has a bean shape, although there are some exceptions, such as the multilobed reniculate kidneys of pinnipeds, cetaceans and bears. Most adult placental mammals have no remaining trace of the cloaca. In the embryo, the embryonic cloaca divides into a posterior region that becomes part of the anus, and an anterior region that has different fates depending on the sex of the individual: in females, it develops into the vestibule that receives the urethra and vagina, while in males it forms the entirety of the penile urethra. However, the tenrecs, golden moles, and some shrews retain a cloaca as adults. In marsupials, the genital tract is separate from the anus, but a trace of the original cloaca does remain externally. Monotremes, which translates from Greek into "single hole", have a true cloaca.
As in all other tetrapods, mammals have a larynx that can quickly open and close to produce sounds, and a supralaryngeal vocal tract which filters this sound. The lungs and surrounding musculature provide the air stream and pressure required to phonate. The larynx controls the pitch and volume of sound, but the strength the lungs exert to exhale also contributes to volume. More primitive mammals, such as the echidna, can only hiss, as sound is achieved solely through exhaling through a partially closed larynx. Other mammals phonate using vocal folds, as opposed to the vocal cords seen in birds and reptiles. The movement or tenseness of the vocal folds can result in many sounds such as purring and screaming. Mammals can change the position of the larynx, allowing them to breathe through the nose while swallowing through the mouth, and to form both oral and nasal sounds; nasal sounds, such as a dog whine, are generally soft sounds, and oral sounds, such as a dog bark, are generally loud.
Some mammals have a large larynx and thus a low-pitched voice, namely the hammer-headed bat (Hypsignathus monstrosus) where the larynx can take up the entirety of the thoracic cavity while pushing the lungs, heart, and trachea into the abdomen. Large vocal pads can also lower the pitch, as in the low-pitched roars of big cats. The production of infrasound is possible in some mammals such as the African elephant (Loxodonta spp.) and baleen whales. Small mammals with small larynxes have the ability to produce ultrasound, which can be detected by modifications to the middle ear and cochlea. Ultrasound is inaudible to birds and reptiles, which might have been important during the Mesozoic, when birds and reptiles were the dominant predators. This private channel is used by some rodents in, for example, mother-to-pup communication, and by bats when echolocating. Toothed whales also use echolocation, but, as opposed to the vocal membrane that extends upward from the vocal folds, they have a melon to manipulate sounds. Some mammals, namely the primates, have air sacs attached to the larynx, which may function to lower the resonances or increase the volume of sound.
The vocal production system is controlled by the cranial nerve nuclei in the brain, and supplied by the recurrent laryngeal nerve and the superior laryngeal nerve, branches of the vagus nerve. The vocal tract is supplied by the hypoglossal nerve and facial nerves. Electrical stimulation of the periaqueductal gray (PEG) region of the mammalian midbrain elicit vocalizations. The ability to learn new vocalizations is only exemplified in humans, seals, cetaceans, elephants and possibly bats; in humans, this is the result of a direct connection between the motor cortex, which controls movement, and the motor neurons in the spinal cord.
- 定期毛髮（Definitive）– 當達到一定長度後即會脫落。
- 感覺毛（Vibrissae）– 用於感測周遭環境。
- 毛皮（Pelage）– 包括護毛、絨毛與芒毛。
- 棘刺（Spine）– 堅硬的毛髮，用於防衛（例如豪豬背上的長刺）。
- 剛毛（Bristle）– 主要用於展示視覺訊號（例如獅子的鬃毛）。
- 柔毛（Velli）– 用於保暖，主要常見於新生的哺乳動物。
- 羊毛（Wool]）– 長而柔軟的卷曲毛髮。
毛髮長度與體溫調節無關：例如，部分棲息於熱帶地區的哺乳動物，如樹懶，具有與極區哺乳動物等長度的毛髮，然而並不具有相當保暖的能力；反而，部分僅具有短毛的熱帶哺乳動物，保暖能力卻與極區哺乳動物相當。毛髮生長的密度可以影響保暖的能力，尤其棲息於極區的哺乳動物都舉有相當高密度的毛髮，例如麝牛除了具有30 cm（12英寸）長的護毛外，還具有高密度的絨毛，能有效鎖住並減少體熱的散失，讓牠們能於−40 °C（−40 °F）的環境下生存:162–163。有些棲息於沙漠的哺乳動物，如駱駝，則透過高密度的毛來將外在環境的熱度隔絕於外，確保個體不會過熱；在夏天時，駱駝的毛髮溫度可達70 °C（158 °F），而皮膚溫度則能維持40 °C（104 °F）:188。水生哺乳動物也具有高密度的毛髮，透過將水隔絕於外保持皮膚乾燥的方式來減少體熱散失:162–163。
大多哺乳動物都會仰賴牠們的體色來進行偽裝，減少被獵物或掠食者發現的機會。棲息於北極及亞北極地區的哺乳動物，如北極狐（Alopex lagopus）、環頸旅鼠 （Dicrostonyx groenlandicus）、白鼬（Mustela erminea）、與白靴兔（Lepus americanus），於夏天時體色為棕色，而在冬天體色為白色，透過這樣毛色的變化來融入周遭環境。樹棲的哺乳動物，主要為靈長類和有袋類，在身上的某些部位具有紫色、綠色或藍色的斑塊，這樣的趋同演化顯示這些斑塊可能有助於牠們在樹棲的環境中生存。
In male placentals, the penis is used both for urination and copulation. Depending on the species, an erection may be fueled by blood flow into vascular, spongy tissue or by muscular action. A penis may be contained in a prepuce when not erect, and some placentals also have a penis bone (baculum). Marsupials typically have forked penises, while the echidna penis generally has four heads with only two functioning. The testes of most mammals descend into the scrotum which is typically posterior to the penis but is often anterior in marsupials. Female mammals generally have a clitoris, labia majora and labia minora on the outside, while the internal system contains paired oviducts, 1-2 uteri, 1-2 cervices and a vagina. Marsupials have two lateral vaginas and a medial vagina. The "vagina" of monotremes is better understood as a "urogenital sinus". The uterine systems of placental mammals can vary between a duplex, were there are two uteri and cervices which open into the vagina, a bipartite, were two uterine horns have a single cervix that connects to the vagina, a bicornuate, which consists where two uterine horns that are connected distally but separate medially creating a Y-shape, and a simplex, which has a single uterus.:220–221, 247
The ancestral condition for mammal reproduction is the birthing of relatively undeveloped, either through direct vivipary or a short period as soft-shelled eggs. This is likely due to the fact that the torso could not expand due to the presence of epipubic bones. The oldest demonstration of this reproductive style is with Kayentatherium, which produced undeveloped perinates, but at much higher litter sizes than any modern mammal, 38 specimens. Most modern mammals are viviparous, giving birth to live young. However, the five species of monotreme, the platypus and the four species of echidna, lay eggs. The monotremes have a sex determination system different from that of most other mammals. In particular, the sex chromosomes of a platypus are more like those of a chicken than those of a therian mammal.
Viviparous mammals are in the subclass Theria; those living today are in the marsupial and placental infraclasses. Marsupials have a short gestation period, typically shorter than its estrous cycle and gives birth to an undeveloped newborn that then undergoes further development; in many species, this takes place within a pouch-like sac, the marsupium, located in the front of the mother's abdomen. This is the plesiomorphic condition among viviparous mammals; the presence of epipubic bones in all non-placental mammals prevents the expansion of the torso needed for full pregnancy. Even non-placental eutherians probably reproduced this way. The placentals give birth to relatively complete and developed young, usually after long gestation periods. They get their name from the placenta, which connects the developing fetus to the uterine wall to allow nutrient uptake. In placental mammals, the epipubic is either completely lost or converted into the baculum; allowing the torso to be able to expand and thus birth developed offspring.
The mammary glands of mammals are specialized to produce milk, the primary source of nutrition for newborns. The monotremes branched early from other mammals and do not have the nipples seen in most mammals, but they do have mammary glands. The young lick the milk from a mammary patch on the mother's belly. Compared to placental mammals, the milk of marsupials changes greatly in both production rate and in nutrient composition, due to the underdeveloped young. In addition, the mammary glands have more autonomy allowing them to supply separate milks to young at different development stages. Lactose is the main sugar in placental mammal milk while monotreme and marsupial milk is dominated by oligosaccharides. Weaning is the process in which a mammal becomes less dependent on their mother's milk and more on solid food.
Nearly all mammals are endothermic ("warm-blooded"). Most mammals also have hair to help keep them warm. Like birds, mammals can forage or hunt in weather and climates too cold for ectothermic ("cold-blooded") reptiles and insects. Endothermy requires plenty of food energy, so mammals eat more food per unit of body weight than most reptiles. Small insectivorous mammals eat prodigious amounts for their size. A rare exception, the naked mole-rat produces little metabolic heat, so it is considered an operational poikilotherm. Birds are also endothermic, so endothermy is not unique to mammals.
Among mammals, species maximum lifespan varies significantly (for example the shrew has a lifespan of two years, whereas the oldest bowhead whale is recorded to be 211 years). Although the underlying basis for these lifespan differences is still uncertain, numerous studies indicate that the ability to repair DNA damage is an important determinant of mammalian lifespan. In a 1974 study by Hart and Setlow, it was found that DNA excision repair capability increased systematically with species lifespan among seven mammalian species. Species lifespan was observed to be robustly correlated with the capacity to recognize DNA double-strand breaks as well as the level of the DNA repair protein Ku80. In a study of the cells from sixteen mammalian species, genes employed in DNA repair were found to be up-regulated in the longer-lived species. The cellular level of the DNA repair enzyme poly ADP ribose polymerase was found to correlate with species lifespan in a study of 13 mammalian species. Three additional studies of a variety of mammalian species also reported a correlation between species lifespan and DNA repair capability.
Most vertebrates—the amphibians, the reptiles and some mammals such as humans and bears—are plantigrade, walking on the whole of the underside of the foot. Many mammals, such as cats and dogs, are digitigrade, walking on their toes, the greater stride length allowing more speed. Digitigrade mammals are also often adept at quiet movement. Some animals such as horses are unguligrade, walking on the tips of their toes. This even further increases their stride length and thus their speed. A few mammals, namely the great apes, are also known to walk on their knuckles, at least for their front legs. Giant anteaters and platypuses are also knuckle-walkers. Some mammals are bipeds, using only two limbs for locomotion, which can be seen in, for example, humans and the great apes. Bipedal species have a larger field of vision than quadrupeds, conserve more energy and have the ability to manipulate objects with their hands, which aids in foraging. Instead of walking, some bipeds hop, such as kangaroos and kangaroo rats.
Animals will use different gaits for different speeds, terrain and situations. For example, horses show four natural gaits, the slowest horse gait is the walk, then there are three faster gaits which, from slowest to fastest, are the trot, the canter and the gallop. Animals may also have unusual gaits that are used occasionally, such as for moving sideways or backwards. For example, the main human gaits are bipedal walking and running, but they employ many other gaits occasionally, including a four-legged crawl in tight spaces. Mammals show a vast range of gaits, the order that they place and lift their appendages in locomotion. Gaits can be grouped into categories according to their patterns of support sequence. For quadrupeds, there are three main categories: walking gaits, running gaits and leaping gaits. Walking is the most common gait, where some feet are on the ground at any given time, and found in almost all legged animals. Running is considered to occur when at some points in the stride all feet are off the ground in a moment of suspension.
Arboreal animals frequently have elongated limbs that help them cross gaps, reach fruit or other resources, test the firmness of support ahead and, in some cases, to brachiate (swing between trees). Many arboreal species, such as tree porcupines, silky anteaters, spider monkeys, and possums, use prehensile tails to grasp branches. In the spider monkey, the tip of the tail has either a bare patch or adhesive pad, which provides increased friction. Claws can be used to interact with rough substrates and reorient the direction of forces the animal applies. This is what allows squirrels to climb tree trunks that are so large to be essentially flat from the perspective of such a small animal. However, claws can interfere with an animal's ability to grasp very small branches, as they may wrap too far around and prick the animal's own paw. Frictional gripping is used by primates, relying upon hairless fingertips. Squeezing the branch between the fingertips generates frictional force that holds the animal's hand to the branch. However, this type of grip depends upon the angle of the frictional force, thus upon the diameter of the branch, with larger branches resulting in reduced gripping ability. To control descent, especially down large diameter branches, some arboreal animals such as squirrels have evolved highly mobile ankle joints that permit rotating the foot into a 'reversed' posture. This allows the claws to hook into the rough surface of the bark, opposing the force of gravity. Small size provides many advantages to arboreal species: such as increasing the relative size of branches to the animal, lower center of mass, increased stability, lower mass (allowing movement on smaller branches) and the ability to move through more cluttered habitat. Size relating to weight affects gliding animals such as the sugar glider. Some species of primate, bat and all species of sloth achieve passive stability by hanging beneath the branch. Both pitching and tipping become irrelevant, as the only method of failure would be losing their grip.
A fossorial (from Latin fossor, meaning "digger") is an animal adapted to digging which lives primarily, but not solely, underground. Some examples are badgers, and naked mole-rats. Many rodent species are also considered fossorial because they live in burrows for most but not all of the day. Species that live exclusively underground are subterranean, and those with limited adaptations to a fossorial lifestyle sub-fossorial. Some organisms are fossorial to aid in temperature regulation while others use the underground habitat for protection from predators or for food storage.
Fossorial mammals have a fusiform body, thickest at the shoulders and tapering off at the tail and nose. Unable to see in the dark burrows, most have degenerated eyes, but degeneration varies between species; pocket gophers, for example, are only semi-fossorial and have very small yet functional eyes, in the fully fossorial marsupial mole the eyes are degenerated and useless, talpa moles have vestigial eyes and the cape golden mole has a layer of skin covering the eyes. External ears flaps are also very small or absent. Truly fossorial mammals have short, stout legs as strength is more important than speed to a burrowing mammal, but semi-fossorial mammals have cursorial legs. The front paws are broad and have strong claws to help in loosening dirt while excavating burrows, and the back paws have webbing, as well as claws, which aids in throwing loosened dirt backwards. Most have large incisors to prevent dirt from flying into their mouth.
Fully aquatic mammals, the cetaceans and sirenians, have lost their legs and have a tail fin to propel themselves through the water. Flipper movement is continuous. Whales swim by moving their tail fin and lower body up and down, propelling themselves through vertical movement, while their flippers are mainly used for steering. Their skeletal anatomy allows them to be fast swimmers. Most species have a dorsal fin to prevent themselves from turning upside-down in the water. The flukes of sirenians are raised up and down in long strokes to move the animal forward, and can be twisted to turn. The forelimbs are paddle-like flippers which aid in turning and slowing.
Semi-aquatic mammals, like pinnipeds, have two pairs of flippers on the front and back, the fore-flippers and hind-flippers. The elbows and ankles are enclosed within the body. Pinnipeds have several adaptions for reducing drag. In addition to their streamlined bodies, they have smooth networks of muscle bundles in their skin that may increase laminar flow and make it easier for them to slip through water. They also lack arrector pili, so their fur can be streamlined as they swim. They rely on their fore-flippers for locomotion in a wing-like manner similar to penguins and sea turtles. Fore-flipper movement is not continuous, and the animal glides between each stroke. Compared to terrestrial carnivorans, the fore-limbs are reduced in length, which gives the locomotor muscles at the shoulder and elbow joints greater mechanical advantage; the hind-flippers serve as stabilizers. Other semi-aquatic mammals include beavers, hippopotamuses, otters and platypuses. Hippos are very large semi-aquatic mammals, and their barrel-shaped bodies have graviportal skeletal structures, adapted to carrying their enormous weight, and their specific gravity allows them to sink and move along the bottom of a river.
Many mammals communicate by vocalizing. Vocal communication serves many purposes, including in mating rituals, as warning calls, to indicate food sources, and for social purposes. Males often call during mating rituals to ward off other males and to attract females, as in the roaring of lions and red deer. The songs of the humpback whale may be signals to females; they have different dialects in different regions of the ocean. Social vocalizations include the territorial calls of gibbons, and the use of frequency in greater spear-nosed bats to distinguish between groups. The vervet monkey gives a distinct alarm call for each of at least four different predators, and the reactions of other monkeys vary according to the call. For example, if an alarm call signals a python, the monkeys climb into the trees, whereas the eagle alarm causes monkeys to seek a hiding place on the ground. Prairie dogs similarly have complex calls that signal the type, size, and speed of an approaching predator. Elephants communicate socially with a variety of sounds including snorting, screaming, trumpeting, roaring and rumbling. Some of the rumbling calls are infrasonic, below the hearing range of humans, and can be heard by other elephants up to 6英里（9.7公里） away at still times near sunrise and sunset.
Mammals signal by a variety of means. Many give visual anti-predator signals, as when deer and gazelle stot, honestly indicating their fit condition and their ability to escape, or when white-tailed deer and other prey mammals flag with conspicuous tail markings when alarmed, informing the predator that it has been detected. Many mammals make use of scent-marking, sometimes possibly to help defend territory, but probably with a range of functions both within and between species. Microbats and toothed whales including oceanic dolphins vocalize both socially and in echolocation.
To maintain a high constant body temperature is energy expensive—mammals therefore need a nutritious and plentiful diet. While the earliest mammals were probably predators, different species have since adapted to meet their dietary requirements in a variety of ways. Some eat other animals—this is a carnivorous diet (and includes insectivorous diets). Other mammals, called herbivores, eat plants, which contain complex carbohydrates such as cellulose. An herbivorous diet includes subtypes such as granivory (seed eating), folivory (leaf eating), frugivory (fruit eating), nectarivory (nectar eating), gummivory (gum eating) and mycophagy (fungus eating). The digestive tract of an herbivore is host to bacteria that ferment these complex substances, and make them available for digestion, which are either housed in the multichambered stomach or in a large cecum. Some mammals are coprophagous, consuming feces to absorb the nutrients not digested when the food was first ingested.:131–137 An omnivore eats both prey and plants. Carnivorous mammals have a simple digestive tract because the proteins, lipids and minerals found in meat require little in the way of specialized digestion. Exceptions to this include baleen whales who also house gut flora in a multi-chambered stomach, like terrestrial herbivores.
The size of an animal is also a factor in determining diet type (Allen's rule). Since small mammals have a high ratio of heat-losing surface area to heat-generating volume, they tend to have high energy requirements and a high metabolic rate. Mammals that weigh less than about 18盎司（510克；1.1英磅） are mostly insectivorous because they cannot tolerate the slow, complex digestive process of an herbivore. Larger animals, on the other hand, generate more heat and less of this heat is lost. They can therefore tolerate either a slower collection process (carnivores that feed on larger vertebrates) or a slower digestive process (herbivores). Furthermore, mammals that weigh more than 18盎司（510克；1.1英磅） usually cannot collect enough insects during their waking hours to sustain themselves. The only large insectivorous mammals are those that feed on huge colonies of insects (ants or termites).
Some mammals are omnivores and display varying degrees of carnivory and herbivory, generally leaning in favor of one more than the other. Since plants and meat are digested differently, there is a preference for one over the other, as in bears where some species may be mostly carnivorous and others mostly herbivorous. They are grouped into three categories: mesocarnivory (50–70% meat), hypercarnivory (70% and greater of meat), and hypocarnivory (50% or less of meat). The dentition of hypocarnivores consists of dull, triangular carnassial teeth meant for grinding food. Hypercarnivores, however, have conical teeth and sharp carnassials meant for slashing, and in some cases strong jaws for bone-crushing, as in the case of hyenas, allowing them to consume bones; some extinct groups, notably the Machairodontinae, had saber-shaped canines.
Some physiological carnivores consume plant matter and some physiological herbivores consume meat. From a behavioral aspect, this would make them omnivores, but from the physiological standpoint, this may be due to zoopharmacognosy. Physiologically, animals must be able to obtain both energy and nutrients from plant and animal materials to be considered omnivorous. Thus, such animals are still able to be classified as carnivores and herbivores when they are just obtaining nutrients from materials originating from sources that do not seemingly complement their classification. For example, it is well documented that some ungulates such as giraffes, camels, and cattle, will gnaw on bones to consume particular minerals and nutrients. Also, cats, which are generally regarded as obligate carnivores, occasionally eat grass to regurgitate indigestible material (such as hairballs), aid with hemoglobin production, and as a laxative.
Many mammals, in the absence of sufficient food requirements in an environment, suppress their metabolism and conserve energy in a process known as hibernation. In the period preceding hibernation, larger mammals, such as bears, become polyphagic to increase fat stores, whereas smaller mammals prefer to collect and stash food. The slowing of the metabolism is accompanied by a decreased heart and respiratory rate, as well as a drop in internal temperatures, which can be around ambient temperature in some cases. For example, the internal temperatures of hibernating arctic ground squirrels can drop to −2.9 °C（26.8 °F）, however the head and neck always stay above 0 °C（32 °F）. A few mammals in hot environments aestivate in times of drought or extreme heat, namely the 肥尾鼠狐猴（Cheirogaleus medius）.
In intelligent mammals, such as primates, the cerebrum is larger relative to the rest of the brain. Intelligence itself is not easy to define, but indications of intelligence include the ability to learn, matched with behavioral flexibility. Rats, for example, are considered to be highly intelligent, as they can learn and perform new tasks, an ability that may be important when they first colonize a fresh habitat. In some mammals, food gathering appears to be related to intelligence: a deer feeding on plants has a brain smaller than a cat, which must think to outwit its prey.
Tool use by animals may indicate different levels of learning and cognition. The sea otter uses rocks as essential and regular parts of its foraging behaviour (smashing abalone from rocks or breaking open shells), with some populations spending 21% of their time making tools. Other tool use, such as chimpanzees using twigs to "fish" for termites, may be developed by watching others use tools and may even be a true example of animal teaching. Tools may even be used in solving puzzles in which the animal appears to experience a "Eureka moment". Other mammals that do not use tools, such as dogs, can also experience a Eureka moment.
Brain size was previously considered a major indicator of the intelligence of an animal. Since most of the brain is used for maintaining bodily functions, greater ratios of brain to body mass may increase the amount of brain mass available for more complex cognitive tasks. Allometric analysis indicates that mammalian brain size scales at approximately the 2⁄3 or 3⁄4 exponent of the body mass. Comparison of a particular animal's brain size with the expected brain size based on such allometric analysis provides an encephalisation quotient that can be used as another indication of animal intelligence. Sperm whales have the largest brain mass of any animal on earth, averaging 8,000立方厘米（490立方英寸） and 7.8公斤（17英磅） in mature males.
Self-awareness appears to be a sign of abstract thinking. Self-awareness, although not well-defined, is believed to be a precursor to more advanced processes such as metacognitive reasoning. The traditional method for measuring this is the mirror test, which determines if an animal possesses the ability of self-recognition. Mammals that have passed the mirror test include Asian elephants (some pass, some do not); chimpanzees; bonobos; orangutans; humans, from 18 months (mirror stage); bottlenose dolphins[a] killer whales; and false killer whales.
Eusociality is the highest level of social organization. These societies have an overlap of adult generations, the division of reproductive labor and cooperative caring of young. Usually insects, such as bees, ants and termites, have eusocial behavior, but it is demonstrated in two rodent species: the naked mole-rat and the Damaraland mole-rat.
Presociality is when animals exhibit more than just sexual interactions with members of the same species, but fall short of qualifying as eusocial. That is, presocial animals can display communal living, cooperative care of young, or primitive division of reproductive labor, but they do not display all of the three essential traits of eusocial animals. Humans and some species of Callitrichidae (marmosets and tamarins) are unique among primates in their degree of cooperative care of young. Harry Harlow set up an experiment with rhesus monkeys, presocial primates, in 1958; the results from this study showed that social encounters are necessary in order for the young monkeys to develop both mentally and sexually.
A fission-fusion society is a society that changes frequently in its size and composition, making up a permanent social group called the "parent group". Permanent social networks consist of all individual members of a community and often varies to track changes in their environment. In a fission–fusion society, the main parent group can fracture (fission) into smaller stable subgroups or individuals to adapt to environmental or social circumstances. For example, a number of males may break off from the main group in order to hunt or forage for food during the day, but at night they may return to join (fusion) the primary group to share food and partake in other activities. Many mammals exhibit this, such as primates (for example orangutans and spider monkeys), elephants, spotted hyenas, lions, and dolphins.
Solitary animals defend a territory and avoid social interactions with the members of its species, except during breeding season. This is to avoid resource competition, as two individuals of the same species would occupy the same niche, and to prevent depletion of food. A solitary animal, while foraging, can also be less conspicuous to predators or prey.
In a hierarchy, individuals are either dominant or submissive. A despotic hierarchy is where one individual is dominant while the others are submissive, as in wolves and lemurs, and a pecking order is a linear ranking of individuals where there is a top individual and a bottom individual. Pecking orders may also be ranked by sex, where the lowest individual of a sex has a higher ranking than the top individual of the other sex, as in hyenas. Dominant individuals, or alphas, have a high chance of reproductive success, especially in harems where one or a few males (resident males) have exclusive breeding rights to females in a group. Non-resident males can also be accepted in harems, but some species, such as the common vampire bat (Desmodus rotundus), may be more strict.
Some mammals are perfectly monogamous, meaning that they mate for life and take no other partners (even after the original mate's death), as with wolves, Eurasian beavers, and otters. There are three types of polygamy: either one or multiple dominant males have breeding rights (polygyny), multiple males that females mate with (polyandry), or multiple males have exclusive relations with multiple females (polygynandry). It is much more common for polygynous mating to happen, which, excluding leks, are estimated to occur in up to 90% of mammals. Lek mating occurs when males congregate around females and try to attract them with various courtship displays and vocalizations, as in harbor seals.
All higher mammals (excluding monotremes) share two major adaptations for care of the young: live birth and lactation. These imply a group-wide choice of a degree of parental care. They may build nests and dig burrows to raise their young in, or feed and guard them often for a prolonged period of time. Many mammals are K-selected, and invest more time and energy into their young than do r-selected animals. When two animals mate, they both share an interest in the success of the offspring, though often to different extremes. Mammalian females exhibit some degree of maternal aggression, another example of parental care, which may be targeted against other females of the species or the young of other females; however, some mammals may "aunt" the infants of other females, and care for them. Mammalian males may play a role in child rearing, as with tenrecs, however this varies species to species, even within the same genus. For example, the males of the southern pig-tailed macaque (Macaca nemestrina) do not participate in child care, whereas the males of the Japanese macaque (M. fuscata) do.
Non-human mammals play a wide variety of roles in human culture. They are the most popular of pets, with tens of millions of dogs, cats and other animals including rabbits and mice kept by families around the world. Mammals such as mammoths, horses and deer are among the earliest subjects of art, being found in Upper Paleolithic cave paintings such as at Lascaux. Major artists such as Albrecht Dürer, George Stubbs and Edwin Landseer are known for their portraits of mammals. Many species of mammals have been hunted for sport and for food; deer and wild boar are especially popular as game animals. Mammals such as horses and dogs are widely raced for sport, often combined with betting on the outcome. There is a tension between the role of animals as companions to humans, and their existence as individuals with rights of their own. Mammals further play a wide variety of roles in literature, film, mythology, and religion.
Domestic mammals form a large part of the livestock raised for meat across the world. They include (2009) around 1.4 billion cattle, 1 billion sheep, 1 billion domestic pigs, and (1985) over 700 million rabbits. Working domestic animals including cattle and horses have been used for work and transport from the origins of agriculture, their numbers declining with the arrival of mechanised transport and agricultural machinery. In 2004 they still provided some 80% of the power for the mainly small farms in the third world, and some 20% of the world's transport, again mainly in rural areas. In mountainous regions unsuitable for wheeled vehicles, pack animals continue to transport goods. Mammal skins provide leather for shoes, clothing and upholstery. Wool from mammals including sheep, goats and alpacas has been used for centuries for clothing. Mammals serve a major role in science as experimental animals, both in fundamental biological research, such as in genetics, and in the development of new medicines, which must be tested exhaustively to demonstrate their safety. Millions of mammals, especially mice and rats, are used in experiments each year. A knockout mouse is a genetically modified mouse with an inactivated gene, replaced or disrupted with an artificial piece of DNA. They enable the study of sequenced genes whose functions are unknown. A small percentage of the mammals are non-human primates, used in research for their similarity to humans.
Charles Darwin, Jared Diamond and others have noted the importance of domesticated mammals in the Neolithic development of agriculture and of civilization, causing farmers to replace hunter-gatherers around the world.[b] This transition from hunting and gathering to herding flocks and growing crops was a major step in human history. The new agricultural economies, based on domesticated mammals, caused "radical restructuring of human societies, worldwide alterations in biodiversity, and significant changes in the Earth's landforms and its atmosphere... momentous outcomes".
Hybrids are offspring resulting from the breeding of two genetically distinct individuals, which usually will result in a high degree of heterozygosity, though hybrid and heterozygous are not synonymous. The deliberate or accidental hybridizing of two or more species of closely related animals through captive breeding is a human activity which has been in existence for millennia and has grown for economic purposes. Hybrids between different subspecies within a species (such as between the Bengal tiger and Siberian tiger) are known as intra-specific hybrids. Hybrids between different species within the same genus (such as between lions and tigers) are known as interspecific hybrids or crosses. Hybrids between different genera (such as between sheep and goats) are known as intergeneric hybrids. Natural hybrids will occur in hybrid zones, where two populations of species within the same genera or species living in the same or adjacent areas will interbreed with each other. Some hybrids have been recognized as species, such as the red wolf (though this is controversial).
Artificial selection, the deliberate selective breeding of domestic animals, is being used to breed back recently extinct animals in an attempt to achieve an animal breed with a phenotype that resembles that extinct wildtype ancestor. A breeding-back (intraspecific) hybrid may be very similar to the extinct wildtype in appearance, ecological niche and to some extent genetics, but the initial gene pool of that wild type is lost forever with its extinction. As a result, bred-back breeds are at best vague look-alikes of extinct wildtypes, as Heck cattle are of the aurochs.
Purebred wild species evolved to a specific ecology can be threatened with extinction through the process of genetic pollution, the uncontrolled hybridization, introgression genetic swamping which leads to homogenization or out-competition from the heterosic hybrid species. When new populations are imported or selectively bred by people, or when habitat modification brings previously isolated species into contact, extinction in some species, especially rare varieties, is possible. Interbreeding can swamp the rarer gene pool and create hybrids, depleting the purebred gene pool. For example, the endangered wild water buffalo is most threatened with extinction by genetic pollution from the domestic water buffalo. Such extinctions are not always apparent from a morphological standpoint. Some degree of gene flow is a normal evolutionary process, nevertheless, hybridization threatens the existence of rare species.
The loss of species from ecological communities, defaunation, is primarily driven by human activity. This has resulted in empty forests, ecological communities depleted of large vertebrates. In the Quaternary extinction event, the mass die-off of megafaunal variety coincided with the appearance of humans, suggesting a human influence. One hypothesis is that humans hunted large mammals, such as the woolly mammoth, into extinction. The 2019 Global Assessment Report on Biodiversity and Ecosystem Services by IPBES states that the total biomass of wild mammals has declined by 82 percent since the beginning of human civilization.
Various species are predicted to become extinct in the near future, among them the rhinoceros, primates, pangolins, and giraffes. Hunting alone threatens hundreds of mammalian species around the world. Scientists claim that the growing demand for meat is contributing to biodiversity loss as this is a significant driver of deforestation and habitat destruction; species-rich habitats, such as significant portions of the Amazon rainforest, are being converted to agricultural land for meat production. According to the World Wildlife Fund's 2016 Living Planet Index, global wildlife populations have declined 58% since 1970, primarily due to habitat destruction, over-hunting and pollution. They project that if current trends continue, 67% of wildlife could disappear by 2020. Another influence is over-hunting and poaching, which can reduce the overall population of game animals, especially those located near villages, as in the case of peccaries. The effects of poaching can especially be seen in the ivory trade with African elephants.[來源請求] Marine mammals are at risk from entanglement from fishing gear, notably cetaceans, with discard mortalities ranging from 65,000 to 86,000 individuals annually.
Attention is being given to endangered species globally, notably through the Convention on Biological Diversity, otherwise known as the Rio Accord, which includes 189 signatory countries that are focused on identifying endangered species and habitats. Another notable conservation organization is the IUCN, which has a membership of over 1,200 governmental and non-governmental organizations.
Recent extinctions can be directly attributed to human influences. The IUCN characterizes 'recent' extinction as those that have occurred past the cut-off point of 1500, and around 80 mammal species have gone extinct since that time and 2015. Some species, such as the Père David's deer are extinct in the wild, and survive solely in captive populations. Other species, such as the Florida panther, are ecologically extinct, surviving in such low numbers that they essentially have no impact on the ecosystem.:318 Other populations are only locally extinct (extirpated), still existing elsewhere, but reduced in distribution,:75–77 as with the extinction of gray whales in the Atlantic.
- List of mammal genera – living mammals
- List of mammalogists
- List of monotremes and marsupials
- List of placental mammals
- List of prehistoric mammals
- List of threatened mammals of the United States
- Lists of mammals by population size
- Lists of mammals by region
- Mammals described in the 2000s
- Mammals in culture
- Benton, Michael; Donoghue, Philip. Paleontological Evidence to Date the Tree of Life. Molecular Biology and Evolution. 2007, 24 (1): 26-53. PMID 17047029. doi:10.1093/molbev/msl150.
- Burgin, C. J.; Colella, J. P.; Kahn, P. L.; Upham, N. S. How many species of mammals are there?. Journal of Mammalogy. 2018, 99 (1): 1–14. ISSN 0022-2372. doi:10.1093/jmammal/gyx147.
- Vaughan TA, Ryan JM, Czaplewski NJ. Classification of Mammals. Mammalogy 6. Jones and Bartlett Learning. 2013. ISBN 978-1-284-03209-3.
- Szalay FS. Classification of Mammals above the Species Level: Review. Journal of Vertebrate Paleontology. 1999, 19 (1): 191–195. JSTOR 4523980. doi:10.1080/02724634.1999.10011133.
- Wilson, D. E., and Reeder, D. M. (编). Mammal species of the world 3rd edition. Johns Hopkins University Press. 2005年. ISBN 0-801-88221-4 （英语）.
- Mammals. The IUCN Red List of Threatened Species. IUCN. April 2010 [23 August 2016].
- Burgin CJ, Colella JP, Kahn PL, Upham NS. How many species of mammals are there?. 哺乳动物学杂志. February 1, 2018, 99 (1): 1–14. doi:10.1093/jmammal/gyx147. 已忽略未知参数
- Rowe T. Definition, diagnosis, and origin of Mammalia (PDF). Journal of Vertebrate Paleontology. 1988, 8 (3): 241–264. doi:10.1080/02724634.1988.10011708.
- Lyell C. The Student's Elements of Geology. London: John Murray. 1871: 347. ISBN 978-1-345-18248-4.
- Cifelli RL, Davis BM. Paleontology. Marsupial origins. Science. December 2003, 302 (5652): 1899–900. PMID 14671280. doi:10.1126/science.1092272.
- Kemp TS. The Origin and Evolution of Mammals (PDF). United Kingdom: Oxford University Press. 2005: 3. ISBN 978-0-19-850760-4. OCLC 232311794.
- Datta PM. Earliest mammal with transversely expanded upper molar from the Late Triassic (Carnian) Tiki Formation, South Rewa Gondwana Basin, India. Journal of Vertebrate Paleontology. 2005, 25 (1): 200–207. doi:10.1671/0272-4634(2005)025[0200:EMWTEU]2.0.CO;2.
- Luo ZX, Martin T. Analysis of Molar Structure and Phylogeny of Docodont Genera (PDF). Bulletin of Carnegie Museum of Natural History. 2007, 39: 27–47 [April 8, 2013]. doi:10.2992/0145-9058(2007)39[27:AOMSAP]2.0.CO;2. （原始内容 (PDF)存档于March 3, 2016）.
- McKenna MC, Bell SG. Classification of Mammals above the Species Level. New York: Columbia University Press. 1997. ISBN 978-0-231-11013-6. OCLC 37345734.
- Nilsson MA, Churakov G, Sommer M, Tran NV, Zemann A, Brosius J, Schmitz J. Tracking marsupial evolution using archaic genomic retroposon insertions. PLoS Biology. July 2010, 8 (7): e1000436. PMC 2910653. PMID 20668664. doi:10.1371/journal.pbio.1000436.
- Kriegs JO, Churakov G, Kiefmann M, Jordan U, Brosius J, Schmitz J. Retroposed elements as archives for the evolutionary history of placental mammals. PLoS Biology. April 2006, 4 (4): e91. PMC 1395351. PMID 16515367. doi:10.1371/journal.pbio.0040091.
- Nishihara H, Maruyama S, Okada N. Retroposon analysis and recent geological data suggest near-simultaneous divergence of the three superorders of mammals. Proceedings of the National Academy of Sciences of the United States of America. March 2009, 106 (13): 5235–40. Bibcode:2009PNAS..106.5235N. PMC 2655268. PMID 19286970. doi:10.1073/pnas.0809297106.
- Springer MS, Murphy WJ, Eizirik E, O'Brien SJ. Placental mammal diversification and the Cretaceous-Tertiary boundary. Proceedings of the National Academy of Sciences of the United States of America. February 2003, 100 (3): 1056–61. Bibcode:2003PNAS..100.1056S. PMC 298725. PMID 12552136. doi:10.1073/pnas.0334222100.
- Tarver JE, Dos Reis M, Mirarab S, Moran RJ, Parker S, O'Reilly JE, 等. The Interrelationships of Placental Mammals and the Limits of Phylogenetic Inference. Genome Biology and Evolution. January 2016, 8 (2): 330–44. PMC 4779606. PMID 26733575. doi:10.1093/gbe/evv261. hdl:1983/64d6e437-3320-480d-a16c-2e5b2e6b61d4.
- Springer MS, Meredith RW, Janecka JE, Murphy WJ. The historical biogeography of Mammalia. Philosophical Transactions of the Royal Society of London B. September 2011, 366 (1577): 2478–502. PMC 3138613. PMID 21807730. doi:10.1098/rstb.2011.0023.
- Meng J, Wang Y, Li C. Transitional mammalian middle ear from a new Cretaceous Jehol eutriconodont. Nature. April 2011, 472 (7342): 181–5. Bibcode:2011Natur.472..181M. PMID 21490668. doi:10.1038/nature09921.
- Ahlberg PE, Milner AR. The Origin and Early Diversification of Tetrapods. Nature. April 1994, 368 (6471): 507–514. Bibcode:1994Natur.368..507A. doi:10.1038/368507a0.
- Amniota – Palaeos. （原始内容存档于2010-12-20）.
- Synapsida overview – Palaeos. （原始内容存档于2010-12-20）.
- Kemp TS. The origin and early radiation of the therapsid mammal-like reptiles: a palaeobiological hypothesis (PDF). Journal of Evolutionary Biology. July 2006, 19 (4): 1231–47. PMID 16780524. doi:10.1111/j.1420-9101.2005.01076.x.
- Bennett AF, Ruben JA. The metabolic and thermoregulatory status of therapsids. (编) Hotton III N, MacLean JJ, Roth J, Roth EC. The ecology and biology of mammal-like reptiles. Washington, DC: Smithsonian Institution Press. 1986: 207–218. ISBN 978-0-87474-524-5.
- Kermack DM, Kermack KA. The evolution of mammalian characters. Washington D.C.: Croom Helm. 1984. ISBN 978-0-7099-1534-8. OCLC 10710687.
- Tanner LH, Lucas SG, Chapman MG. Assessing the record and causes of Late Triassic extinctions (PDF). Earth-Science Reviews. 2004, 65 (1–2): 103–139. Bibcode:2004ESRv...65..103T. doi:10.1016/S0012-8252(03)00082-5. （原始内容 (PDF)存档于October 25, 2007）.
- Brusatte SL, Benton MJ, Ruta M, Lloyd GT. Superiority, competition, and opportunism in the evolutionary radiation of dinosaurs (PDF). Science. September 2008, 321 (5895): 1485–8. Bibcode:2008Sci...321.1485B. PMID 18787166. doi:10.1126/science.1161833.
- Gauthier JA. Saurischian monophyly and the origin of birds. (编) Padian K. The Origin of Birds and the Evolution of Flight. Memoirs of the California Academy of Sciences 8. San Francisco: California Academy of Sciences. 1986: 1–55.
- Sereno PC. Basal archosaurs: phylogenetic relationships and functional implications. Memoirs of the Society of Vertebrate Paleontology. 1991, 2: 1–53. JSTOR 3889336. doi:10.2307/3889336.
- MacLeod N, Rawson PF, Forey PL, Banner FT, Boudagher-Fadel MK, Bown PR, 等. The Cretaceous–Tertiary biotic transition. Journal of the Geological Society. 1997, 154 (2): 265–292. Bibcode:1997JGSoc.154..265M. doi:10.1144/gsjgs.154.2.0265.
- Hunt DM, Hankins MW, Collin SP, Marshall NJ. Evolution of Visual and Non-visual Pigments. London: Springer. : 73. ISBN 978-1-4614-4354-4. OCLC 892735337.
- Bakalar N. Jurassic "Beaver" Found; Rewrites History of Mammals. National Geographic News. 2006 [28 May 2016].
- Hall MI, Kamilar JM, Kirk EC. Eye shape and the nocturnal bottleneck of mammals. Proceedings of the Royal Society B: Biological Sciences. December 2012, 279 (1749): 4962–8. PMC 3497252. PMID 23097513. doi:10.1098/rspb.2012.2258.
- Luo ZX. Transformation and diversification in early mammal evolution. Nature. December 2007, 450 (7172): 1011–9. Bibcode:2007Natur.450.1011L. PMID 18075580. doi:10.1038/nature06277.
- Pickrell J. Oldest Marsupial Fossil Found in China. National Geographic News. 2003 [28 May 2016].
- Luo ZX, Yuan CX, Meng QJ, Ji Q. A Jurassic eutherian mammal and divergence of marsupials and placentals. Nature. August 2011, 476 (7361): 442–5. Bibcode:2011Natur.476..442L. PMID 21866158. doi:10.1038/nature10291.
- Ji Q, Luo ZX, Yuan CX, Wible JR, Zhang JP, Georgi JA. The earliest known eutherian mammal. Nature. April 2002, 416 (6883): 816–22. Bibcode:2002Natur.416..816J. PMID 11976675. doi:10.1038/416816a.
- Novacek MJ, Rougier GW, Wible JR, McKenna MC, Dashzeveg D & Horovitz I. Epipubic bones in eutherian mammals from the late Cretaceous of Mongolia. Nature. October 1997, 389 (6650): 483–6. Bibcode:1997Natur.389..483N. PMID 9333234. doi:10.1038/39020.
- Power ML, Schulkin J. Evolution of Live Birth in Mammals. Evolution of the Human Placenta. Baltimore: Johns Hopkins University Press. 2012: 68. ISBN 978-1-4214-0643-5.
- Rowe T, Rich TH, Vickers-Rich P, Springer M, Woodburne MO. The oldest platypus and its bearing on divergence timing of the platypus and echidna clades. Proceedings of the National Academy of Sciences of the United States of America. January 2008, 105 (4): 1238–42. Bibcode:2008PNAS..105.1238R. PMC 2234122. PMID 18216270. doi:10.1073/pnas.0706385105.
- Grant T. Reproduction. The Platypus: A Unique Mammal. Sydney: University of New South Wales. 1995: 55. ISBN 978-0-86840-143-0. OCLC 33842474.
- Goldman AS. Evolution of immune functions of the mammary gland and protection of the infant. Breastfeeding Medicine. June 2012, 7 (3): 132–42. PMID 22577734. doi:10.1089/bfm.2012.0025.
- Rose KD. The Beginning of the Age of Mammals. Baltimore: Johns Hopkins University Press. 2006: 82–83. ISBN 978-0-8018-8472-6. OCLC 646769601.
- Brink AS. A study on the skeleton of Diademodon. Palaeontologia Africana. 1955, 3: 3–39.
- Kemp TS. Mammal-like reptiles and the origin of mammals. London: Academic Press. 1982: 363. ISBN 978-0-12-404120-2. OCLC 8613180.
- Estes R. Cranial anatomy of the cynodont reptile Thrinaxodon liorhinus. Bulletin of the Museum of Comparative Zoology. 1961, (1253): 165–180.
- Thrinaxodon: The Emerging Mammal. National Geographic Daily News. February 11, 2009 [August 26, 2012].
- Bajdek P, Qvarnström M, Owocki K, Sulej T, Sennikov AG, Golubev VK, Niedźwiedzki G. Microbiota and food residues including possible evidence of pre-mammalian hair in Upper Permian coprolites from Russia. Lethaia. 2015, 49 (4): 455–477. doi:10.1111/let.12156.
- Botha-Brink J, Angielczyk KD. Do extraordinarily high growth rates in Permo-Triassic dicynodonts (Therapsida, Anomodontia) explain their success before and after the end-Permian extinction?. Zoological Journal of the Linnean Society. 2010, 160 (2): 341–365. doi:10.1111/j.1096-3642.2009.00601.x.
- Paul GS. Predatory Dinosaurs of the World. New York: Simon and Schuster. 1988: 464. ISBN 978-0-671-61946-6. OCLC 18350868.
- Watson JM, Graves JA. Monotreme Cell-Cycles and the Evolution of Homeothermy. Australian Journal of Zoology. 1988, 36 (5): 573–584. doi:10.1071/ZO9880573.
- McNab BK. Energetics and the limits to the temperate distribution in armadillos. Journal of Mammalogy. 1980, 61 (4): 606–627. JSTOR 1380307. doi:10.2307/1380307.
- Kielan-Jaworowska Z, Hurum JH. Limb posture in early mammals: Sprawling or parasagittal (PDF). Acta Palaeontologica Polonica. 2006, 51 (3): 10237–10239.
- Lillegraven JA, Kielan-Jaworowska Z, Clemens WA. Mesozoic Mammals: The First Two-Thirds of Mammalian History. University of California Press. 1979: 321. ISBN 978-0-520-03951-3. OCLC 5910695.
- Oftedal OT. The mammary gland and its origin during synapsid evolution. Journal of Mammary Gland Biology and Neoplasia. July 2002, 7 (3): 225–52. PMID 12751889. doi:10.1023/A:1022896515287.
- Oftedal OT. The origin of lactation as a water source for parchment-shelled eggs. Journal of Mammary Gland Biology and Neoplasia. July 2002, 7 (3): 253–66. PMID 12751890. doi:10.1023/A:1022848632125.
- Sahney S, Benton MJ, Ferry PA. Links between global taxonomic diversity, ecological diversity and the expansion of vertebrates on land (PDF). Biology Letters. August 2010, 6 (4): 544–7 [2011-02-10]. PMC 2936204. PMID 20106856. doi:10.1098/rsbl.2009.1024. （原始内容 (PDF)存档于2015-11-06）.
- Smith FA, Boyer AG, Brown JH, Costa DP, Dayan T, Ernest SK, 等. The evolution of maximum body size of terrestrial mammals. Science. November 2010, 330 (6008): 1216–9. Bibcode:2010Sci...330.1216S. PMID 21109666. doi:10.1126/science.1194830.
- Simmons NB, Seymour KL, Habersetzer J, Gunnell GF. Primitive Early Eocene bat from Wyoming and the evolution of flight and echolocation. Nature. February 2008, 451 (7180): 818–21. Bibcode:2008Natur.451..818S. PMID 18270539. doi:10.1038/nature06549. hdl:2027.42/62816.
- Bininda-Emonds OR, Cardillo M, Jones KE, MacPhee RD, Beck RM, Grenyer R, 等. The delayed rise of present-day mammals (PDF). Nature. March 2007, 446 (7135): 507–12. Bibcode:2007Natur.446..507B. PMID 17392779. doi:10.1038/nature05634.
- Wible JR, Rougier GW, Novacek MJ, Asher RJ. Cretaceous eutherians and Laurasian origin for placental mammals near the K/T boundary. Nature. June 2007, 447 (7147): 1003–6. Bibcode:2007Natur.447.1003W. PMID 17581585. doi:10.1038/nature05854.
- O'Leary MA, Bloch JI, Flynn JJ, Gaudin TJ, Giallombardo A, Giannini NP, 等. The placental mammal ancestor and the post-K-Pg radiation of placentals. Science. February 2013, 339 (6120): 662–7. Bibcode:2013Sci...339..662O. PMID 23393258. doi:10.1126/science.1229237.
- Halliday TJ, Upchurch P, Goswami A. Resolving the relationships of Paleocene placental mammals. Biological Reviews of the Cambridge Philosophical Society. February 2017, 92 (1): 521–550. PMC 6849585. PMID 28075073. doi:10.1111/brv.12242.
- Halliday TJ, Upchurch P, Goswami A. Eutherians experienced elevated evolutionary rates in the immediate aftermath of the Cretaceous-Palaeogene mass extinction. Proceedings. Biological Sciences. June 2016, 283 (1833): 20153026. PMC 4936024. PMID 27358361. doi:10.1098/rspb.2015.3026.
- Ni X, Gebo DL, Dagosto M, Meng J, Tafforeau P, Flynn JJ, Beard KC. The oldest known primate skeleton and early haplorhine evolution. Nature. June 2013, 498 (7452): 60–4. Bibcode:2013Natur.498...60N. PMID 23739424. doi:10.1038/nature12200.
- Romer SA, Parsons TS. The Vertebrate Body. Philadelphia: Holt-Saunders International. 1977: 129–145. ISBN 978-0-03-910284-5. OCLC 60007175.
- Purves WK, Sadava DE, Orians GH, Helle HC. Life: The Science of Biology 6. New York: Sinauer Associates, Inc. 2001: 593. ISBN 978-0-7167-3873-2. OCLC 874883911.
- Anthwal N, Joshi L, Tucker AS. Evolution of the mammalian middle ear and jaw: adaptations and novel structures. Journal of Anatomy. January 2013, 222 (1): 147–60. PMC 3552421. PMID 22686855. doi:10.1111/j.1469-7580.2012.01526.x.
- van Nievelt AF, Smith KK. To replace or not to replace: the significance of reduced functional tooth replacement in marsupial and placental mammals. Paleobiology. 2005, 31 (2): 324–346. doi:10.1666/0094-8373(2005)031[0324:trontr]2.0.co;2.
- Libertini, G.; Ferrara, N. Aging of perennial cells and organ parts according to the programmed aging paradigm. AGE. 2016, 38 (35). PMC 5005898. PMID 26957493. doi:10.1007/s11357-016-9895-0.
- Mao F, Wang Y, Meng J. A Systematic Study on Tooth Enamel Microstructures of Lambdopsalis bulla (Multituberculate, Mammalia)--Implications for Multituberculate Biology and Phylogeny. PLOS ONE. 2015, 10 (5): e0128243. Bibcode:2015PLoSO..1028243M. PMC 4447277. PMID 26020958. doi:10.1371/journal.pone.0128243.
- Osborn HF. Origin of the Mammalia, III. Occipital Condyles of Reptilian Tripartite Type. The American Naturalist. 1900, 34 (408): 943–947. JSTOR 2453526. doi:10.1086/277821.
- Crompton AW, Jenkins Jr FA. Mammals from Reptiles: A Review of Mammalian Origins. Annual Review of Earth and Planetary Sciences. 1973, 1: 131–155. Bibcode:1973AREPS...1..131C. doi:10.1146/annurev.ea.01.050173.001023.
- Power ML, Schulkin J. The Evolution Of The Human Placenta. Baltimore: Johns Hopkins University Press. 2013: 1890–1891. ISBN 978-1-4214-0643-5. OCLC 940749490.
- Dierauf LA, Gulland FM. CRC Handbook of Marine Mammal Medicine: Health, Disease, and Rehabilitation 2. Boca Raton: CRC Press. 2001: 154. ISBN 978-1-4200-4163-7. OCLC 166505919.
- Lui JH, Hansen DV, Kriegstein AR. Development and evolution of the human neocortex. Cell. July 2011, 146 (1): 18–36. PMC 3610574. PMID 21729779. doi:10.1016/j.cell.2011.06.030.
- Keeler CE. Absence of the Corpus Callosum as a Mendelizing Character in the House Mouse. Proceedings of the National Academy of Sciences of the United States of America. June 1933, 19 (6): 609–11. Bibcode:1933PNAS...19..609K. JSTOR 86284. PMC 1086100. PMID 16587795. doi:10.1073/pnas.19.6.609.
- Levitzky MG. Mechanics of Breathing. Pulmonary physiology 8. New York: McGraw-Hill Medical. 2013. ISBN 978-0-07-179313-1. OCLC 940633137.
- Umesh KB. Pulmonary Anatomy and Physiology. Handbook of Mechanical Ventilation 1. New Delhi: Jaypee Brothers Medical Publishing. 2011: 12. ISBN 978-93-80704-74-6. OCLC 945076700.
- Standring S, Borley NR. Gray's anatomy: the anatomical basis of clinical practice 40. London: Churchill Livingstone. 2008: 960–962. ISBN 978-0-8089-2371-8. OCLC 213447727.
- Betts JG, Desaix P, Johnson E, Johnson JE, Korol O, Kruse D, Poe B, Wise JA, Womble M, Young KA. Anatomy & physiology. Houston: Rice University Press. 2013: 787–846. ISBN 978-1-938168-13-0. OCLC 898069394.
- Feldhamer GA, Drickamer LC, Vessey SH, Merritt JH, Krajewski C. Mammalogy: Adaptation, Diversity, Ecology 3. Baltimore: Johns Hopkins University Press. 2007. ISBN 978-0-8018-8695-9. OCLC 124031907.
- Tinker SW. Whales of the World. Brill Archive. 1988: 51. ISBN 978-0-935848-47-2.
- Romer AS. The vertebrate story 4. Chicago: University of Chicago Press. 1959. ISBN 978-0-226-72490-4. 已忽略未知参数
- de Muizon C, Lange-Badré B. Carnivorous dental adaptations in tribosphenic mammals and phylogenetic reconstruction. Lethaia. 1997, 30 (4): 353–366. doi:10.1111/j.1502-3931.1997.tb00481.x.
- Langer P. Comparative anatomy of the stomach in mammalian herbivores. Quarterly Journal of Experimental Physiology. July 1984, 69 (3): 615–25. PMID 6473699. doi:10.1113/expphysiol.1984.sp002848.
- Vaughan TA, Ryan JM, Czaplewski NJ. Perissodactyla. Mammalogy 5. Jones and Bartlett. 2011: 322. ISBN 978-0-7637-6299-5. OCLC 437300511.
- Flower WH, Lydekker R. An Introduction to the Study of Mammals Living and Extinct. London: Adam and Charles Black. 1946: 496. ISBN 978-1-110-76857-8.
- Sreekumar S. Basic Physiology. PHI Learning Pvt. Ltd. 2010: 180–181. ISBN 978-81-203-4107-4.
- Cheifetz AS. Oxford American Handbook of Gastroenterology and Hepatology. Oxford: Oxford University Press, US. 2010: 165. ISBN 978-0-19-983012-1.
- Kuntz E. Hepatology: Textbook and Atlas. Germany: Springer. 2008: 38. ISBN 978-3-540-76838-8.
- Ortiz RM. Osmoregulation in marine mammals. The Journal of Experimental Biology. June 2001, 204 (Pt 11): 1831–44. PMID 11441026.
- Roman AS, Parsons TS. The Vertebrate Body. Philadelphia: Holt-Saunders International. 1977: 396–399. ISBN 978-0-03-910284-5.
- Biological Reviews – Cambridge Journals
- Dawkins R, Wong Y. The Ancestor's Tale: A Pilgrimage to the Dawn of Evolution 2nd. Boston: Mariner Books. 2016: 281. ISBN 978-0-544-85993-7.
- Fitch WT. Production of Vocalizations in Mammals (PDF). (编) Brown K. Encyclopedia of Language and Linguistics. Oxford: Elsevier. 2006: 115–121.
- Langevin P, Barclay RM. Hypsignathus monstrosus. Mammalian Species. 1990, 357 (357): 1–4. JSTOR 3504110. doi:10.2307/3504110.
- Weissengruber GE, Forstenpointner G, Peters G, Kübber-Heiss A, Fitch WT. Hyoid apparatus and pharynx in the lion (Panthera leo), jaguar (Panthera onca), tiger (Panthera tigris), cheetah (Acinonyxjubatus) and domestic cat (Felis silvestris f. catus). Journal of Anatomy. September 2002, 201 (3): 195–209. PMC 1570911. PMID 12363272. doi:10.1046/j.1469-7580.2002.00088.x.
- Stoeger AS, Heilmann G, Zeppelzauer M, Ganswindt A, Hensman S, Charlton BD. Visualizing sound emission of elephant vocalizations: evidence for two rumble production types. PLOS ONE. 2012, 7 (11): e48907. Bibcode:2012PLoSO...748907S. PMC 3498347. PMID 23155427. doi:10.1371/journal.pone.0048907.
- Clark CW. Baleen whale infrasonic sounds: Natural variability and function. Journal of the Acoustical Society of America. 2004, 115 (5): 2554. Bibcode:2004ASAJ..115.2554C. doi:10.1121/1.4783845.
- Dawson TJ, Webster KN, Maloney SK. The fur of mammals in exposed environments; do crypsis and thermal needs necessarily conflict? The polar bear and marsupial koala compared. Journal of Comparative Physiology B. February 2014, 184 (2): 273–84. PMID 24366474. doi:10.1007/s00360-013-0794-8.
- Slominski A, Tobin DJ, Shibahara S, Wortsman J. Melanin pigmentation in mammalian skin and its hormonal regulation. Physiological Reviews. October 2004, 84 (4): 1155–228. PMID 15383650. doi:10.1152/physrev.00044.2003.
- Hilton Jr B. South Carolina Wildlife. Animal Colors (Hilton Pond Center). 1996, 43 (4): 10–15 [26 November 2011].
- Prum RO, Torres RH. Structural colouration of mammalian skin: convergent evolution of coherently scattering dermal collagen arrays (PDF). The Journal of Experimental Biology. May 2004, 207 (Pt 12): 2157–72. PMID 15143148. doi:10.1242/jeb.00989. hdl:1808/1599.
- Suutari M, Majaneva M, Fewer DP, Voirin B, Aiello A, Friedl T, 等. Molecular evidence for a diverse green algal community growing in the hair of sloths and a specific association with Trichophilus welckeri (Chlorophyta, Ulvophyceae). BMC Evolutionary Biology. March 2010, 10 (86): 86. PMC 2858742. PMID 20353556. doi:10.1186/1471-2148-10-86.
- Caro T. The Adaptive Significance of Coloration in Mammals (PDF). BioScience. 2005, 55 (2): 125–136. doi:10.1641/0006-3568(2005)055[0125:tasoci]2.0.co;2.
- Mills LS, Zimova M, Oyler J, Running S, Abatzoglou JT, Lukacs PM. Camouflage mismatch in seasonal coat color due to decreased snow duration. Proceedings of the National Academy of Sciences of the United States of America. April 2013, 110 (18): 7360–5. Bibcode:2013PNAS..110.7360M. PMC 3645584. PMID 23589881. doi:10.1073/pnas.1222724110.
- Caro T. Contrasting coloration in terrestrial mammals. Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences. February 2009, 364 (1516): 537–48. PMC 2674080. PMID 18990666. doi:10.1098/rstb.2008.0221.
- Plavcan JM. Sexual dimorphism in primate evolution. American Journal of Physical Anthropology. 2001,. Suppl 33 (33): 25–53. PMID 11786990. doi:10.1002/ajpa.10011.
- Bradley BJ, Gerald MS, Widdig A, Mundy NI. Coat Color Variation and Pigmentation Gene Expression in Rhesus Macaques (Macaca Mulatta) (PDF). Journal of Mammalian Evolution. 2012, 20 (3): 263–270. doi:10.1007/s10914-012-9212-3. （原始内容 (PDF)存档于2015-09-24）.
- Caro T, Izzo A, Reiner RC, Walker H, Stankowich T. The function of zebra stripes. Nature Communications. April 2014, 5: 3535. Bibcode:2014NatCo...5.3535C. PMID 24691390. doi:10.1038/ncomms4535.
- Lombardi J. Comparative Vertebrate Reproduction. Springer Science & Business Media. 30 November 1998. ISBN 978-0-7923-8336-9.
- Tyndale-Biscoe H, Renfree M. Reproductive Physiology of Marsupials. Cambridge University Press. 30 January 1987. ISBN 978-0-521-33792-2.
- Johnston SD, Smith B, Pyne M, Stenzel D, Holt WV. One‐Sided Ejaculation of Echidna Sperm Bundles (PDF). The American Naturalist. 2007, 170 (6): E162–E164. PMID 18171162. doi:10.1086/522847.
- Maxwell KE. The Sex Imperative: An Evolutionary Tale of Sexual Survival. Springer. 2013: 112–113. ISBN 978-1-4899-5988-1.
- Vaughan TA, Ryan JP, Czaplewski NJ. Mammalogy. Jones & Bartlett Publishers. 2011: 387. ISBN 978-0-03-025034-7.
- Hoffman EA, Rowe TB. Jurassic stem-mammal perinates and the origin of mammalian reproduction and growth. Nature. September 2018, 561 (7721): 104–108. Bibcode:2018Natur.561..104H. PMID 30158701. doi:10.1038/s41586-018-0441-3.
- Wallis MC, Waters PD, Delbridge ML, Kirby PJ, Pask AJ, Grützner F, 等. Sex determination in platypus and echidna: autosomal location of SOX3 confirms the absence of SRY from monotremes. Chromosome Research. 2007, 15 (8): 949–59. PMID 18185981. doi:10.1007/s10577-007-1185-3.
- Marshall Graves JA. Weird animal genomes and the evolution of vertebrate sex and sex chromosomes (PDF). Annual Review of Genetics. 2008, 42: 565–86. PMID 18983263. doi:10.1146/annurev.genet.42.110807.091714. （原始内容 (PDF)存档于2012-09-04）. 已忽略未知参数
- Novacek MJ, Rougier GW, Wible JR, McKenna MC, Dashzeveg D, Horovitz I. Epipubic bones in eutherian mammals from the late Cretaceous of Mongolia. Nature. October 1997, 389 (6650): 483–6. Bibcode:1997Natur.389..483N. PMID 9333234. doi:10.1038/39020.
- Morgan S. Mammal Behavior and Lifestyle. Mammals. Chicago: Raintree. 2005: 6. ISBN 978-1-4109-1050-9. OCLC 53476660.
- Verma PS, Pandey BP. ISC Biology Book I for Class XI. New Delhi: S. Chand and Company. 2013: 288. ISBN 978-81-219-2557-0.
- Oftedal OT. The mammary gland and its origin during synapsid evolution. Journal of Mammary Gland Biology and Neoplasia. July 2002, 7 (3): 225–52. PMID 12751889. doi:10.1023/a:1022896515287.
- Krockenberger A. Lactation. (编) Dickman CR, Armati PJ, Hume ID. Marsupials. 2006: 109. ISBN 9781139457422.
- Schulkin J, Power ML. Milk: The Biology of Lactation. Johns Hopkins University Press. 2016: 66. ISBN 9781421420424.
- Thompson KV, Baker AJ, Baker AM. Paternal Care and Behavioral Development in Captive Mammals. (编) Baer CK, Kleiman DG, Thompson KV. Wild Mammals in Captivity Principles and Techniques for Zoo Management 2nd. University of Chicago Press. 2010: 374. ISBN 9780226440118.
- Campbell NA, Reece JB. Biology 6. Benjamin Cummings. 2002: 845. ISBN 978-0-8053-6624-2. OCLC 47521441.
- Buffenstein R, Yahav S. Is the naked mole-rat Hererocephalus glaber an endothermic yet poikilothermic mammal?. Journal of Thermal Biology. 1991, 16 (4): 227–232. doi:10.1016/0306-4565(91)90030-6.
- Schmidt-Nielsen K, Duke JB. Temperature Effects. Animal Physiology: Adaptation and Environment 5. Cambridge. 1997: 218. ISBN 978-0-521-57098-5. OCLC 35744403.
- Lorenzini A, Johnson FB, Oliver A, Tresini M, Smith JS, Hdeib M, 等. Significant correlation of species longevity with DNA double strand break recognition but not with telomere length. Mechanisms of Ageing and Development. 2009, 130 (11–12): 784–92. PMC 2799038. PMID 19896964. doi:10.1016/j.mad.2009.10.004.
- Hart RW, Setlow RB. Correlation between deoxyribonucleic acid excision-repair and life-span in a number of mammalian species. Proceedings of the National Academy of Sciences of the United States of America. June 1974, 71 (6): 2169–73. Bibcode:1974PNAS...71.2169H. PMC 388412. PMID 4526202. doi:10.1073/pnas.71.6.2169.
- Ma S, Upneja A, Galecki A, Tsai YM, Burant CF, Raskind S, 等. Cell culture-based profiling across mammals reveals DNA repair and metabolism as determinants of species longevity. eLife. November 2016, 5. PMC 5148604. PMID 27874830. doi:10.7554/eLife.19130.
- Grube K, Bürkle A. Poly(ADP-ribose) polymerase activity in mononuclear leukocytes of 13 mammalian species correlates with species-specific life span. Proceedings of the National Academy of Sciences of the United States of America. December 1992, 89 (24): 11759–63. Bibcode:1992PNAS...8911759G. PMC 50636. PMID 1465394. doi:10.1073/pnas.89.24.11759.
- Francis AA, Lee WH, Regan JD. The relationship of DNA excision repair of ultraviolet-induced lesions to the maximum life span of mammals. Mechanisms of Ageing and Development. June 1981, 16 (2): 181–9. PMID 7266079. doi:10.1016/0047-6374(81)90094-4.
- Treton JA, Courtois Y. Correlation between DNA excision repair and mammalian lifespan in lens epithelial cells. Cell Biology International Reports. March 1982, 6 (3): 253–60. PMID 7060140. doi:10.1016/0309-1651(82)90077-7.
- Maslansky CJ, Williams GM. Ultraviolet light-induced DNA repair synthesis in hepatocytes from species of differing longevities. Mechanisms of Ageing and Development. February 1985, 29 (2): 191–203. PMID 3974310. doi:10.1016/0047-6374(85)90018-1.
- Leg and feet. Avian Sketetal Adaptations. [3 August 2008]. （原始内容存档于2008-04-04）.
- Walker WF, Homberger DG. Anatomy and Dissection of the Fetal Pig 5. New York: W. H. Freeman and Company. 1998: 3. ISBN 978-0-7167-2637-1. OCLC 40576267.
- Orr CM. Knuckle-walking anteater: a convergence test of adaptation for purported knuckle-walking features of African Hominidae. American Journal of Physical Anthropology. November 2005, 128 (3): 639–58. PMID 15861420. doi:10.1002/ajpa.20192.
- Fish FE, Frappell PB, Baudinette RV, MacFarlane PM. Energetics of terrestrial locomotion of the platypus Ornithorhynchus anatinus (PDF). The Journal of Experimental Biology. February 2001, 204 (Pt 4): 797–803. PMID 11171362.
- Dhingra P. Comparative Bipedalism – How the Rest of the Animal Kingdom Walks on two legs. Anthropological Science. 2004, 131 (231).
- Alexander RM. Bipedal animals, and their differences from humans. Journal of Anatomy. May 2004, 204 (5): 321–30. PMC 1571302. PMID 15198697. doi:10.1111/j.0021-8782.2004.00289.x.
- Dagg AI. Gaits in Mammals. Mammal Review. 1973, 3 (4): 135–154. doi:10.1111/j.1365-2907.1973.tb00179.x.
- Roberts TD. Understanding Balance: The Mechanics of Posture and Locomotion. San Diego: Nelson Thornes. 1995: 211. ISBN 978-1-56593-416-0. OCLC 33167785.
- Cartmill M. Climbing. (编) Hildebrand M, Bramble DM, Liem KF, Wake DB. Functional Vertebrate Morphology. Cambridge: Belknap Press. 1985: 73–88. ISBN 978-0-674-32775-7. OCLC 11114191.
- Vernes K. Gliding Performance of the Northern Flying Squirrel (Glaucomys sabrinus) in Mature Mixed Forest of Eastern Canada (PDF). Journal of Mammalogy. 2001, 82 (4): 1026–1033. doi:10.1644/1545-1542(2001)082<1026:GPOTNF>2.0.CO;2.
- Barba LA. Bats – the only flying mammals. Bio-Aerial Locomotion. October 2011 [20 May 2016].
- Bats In Flight Reveal Unexpected Aerodynamics. ScienceDaily. 2007 [July 12, 2016].
- Hedenström A, Johansson LC. Bat flight: aerodynamics, kinematics and flight morphology (PDF). The Journal of Experimental Biology. March 2015, 218 (Pt 5): 653–63. PMID 25740899. doi:10.1242/jeb.031203.
- Bats save energy by drawing in wings on upstroke. ScienceDaily. 2012 [July 12, 2016].
- Taschek K. Hanging with Bats: Ecobats, Vampires, and Movie Stars. Albuquerque: University of New Mexico Press. 2008: 14. ISBN 978-0-8263-4403-8. OCLC 191258477.
- Sterbing-D'Angelo S, Chadha M, Chiu C, Falk B, Xian W, Barcelo J, 等. Bat wing sensors support flight control (PDF). Proceedings of the National Academy of Sciences of the United States of America. July 2011, 108 (27): 11291–6. Bibcode:2011PNAS..10811291S. PMC 3131348. PMID 21690408. doi:10.1073/pnas.1018740108.
- Damiani, R, 2003, Earliest evidence of cynodont burrowing, The Royal Society Publishing, Volume 270, Issue 1525
- Shimer HW. Adaptations to Aquatic, Arboreal, Fossorial and Cursorial Habits in Mammals. III. Fossorial Adaptations. The American Naturalist. 1903, 37 (444): 819–825. JSTOR 2455381. doi:10.1086/278368.
- Stanhope, M. J.; Waddell, V. G.; 等. Molecular evidence for multiple origins of Insectivora and for a new order of endemic African insectivore mammals. Proceedings of the National Academy of Sciences. 1998, 95 (17): 9967–9972. Bibcode:1998PNAS...95.9967S. PMC 21445. PMID 9707584. doi:10.1073/pnas.95.17.9967. 已忽略未知参数
- Perry DA. The anatomical basis of swimming in Whales. Journal of Zoology. 1949, 119 (1): 49–60. doi:10.1111/j.1096-3642.1949.tb00866.x.
- Fish FE, Hui CA. Dolphin swimming – a review (PDF). Mammal Review. 1991, 21 (4): 181–195. doi:10.1111/j.1365-2907.1991.tb00292.x. （原始内容 (PDF)存档于2006-08-29）. 已忽略未知参数
- Marsh H. Chapter 57: Dugongidae (PDF). Fauna of Australia 1. Canberra: Australian Government Publications. 1989. ISBN 978-0-644-06056-1. OCLC 27492815. （原始内容 (PDF)存档于2013-05-11）. 已忽略未知参数
- Berta A. Pinniped Diversity: Evolution and Adaptations. Return to the Sea: The Life and Evolutionary Times of Marine Mammals. University of California Press. April 2012: 62–64. ISBN 978-0-520-27057-2.
- Fish FE, Hurley J, Costa DP. Maneuverability by the sea lion Zalophus californianus: turning performance of an unstable body design. The Journal of Experimental Biology. February 2003, 206 (Pt 4): 667–74. PMID 12517984. doi:10.1242/jeb.00144. 已忽略未知参数
- Riedman M. The Pinnipeds: Seals, Sea Lions, and Walruses. University of California Press. 1990. ISBN 978-0-520-06497-3. OCLC 19511610. 已忽略未知参数
- Fish FE. Transitions from drag-based to lift-based propulsion in mammalian swimming. Integrative and Comparative Biology. 1996, 36 (6): 628–641. doi:10.1093/icb/36.6.628. 已忽略未知参数
- Fish FE. Biomechanics and energetics in aquatic and semiaquatic mammals: platypus to whale (PDF). Physiological and Biochemical Zoology. 2000, 73 (6): 683–98. PMID 11121343. doi:10.1086/318108. （原始内容 (PDF)存档于2016-08-04）. 已忽略未知参数
- Eltringham SK. Anatomy and Physiology. The Hippos. London: T & AD Poyser Ltd. 1999: 8. ISBN 978-0-85661-131-5. OCLC 42274422.
- Hippopotamus Hippopotamus amphibius. National Geographic. [30 April 2016]. （原始内容存档于2014-11-25）. 已忽略未知参数
- Seyfarth RM, Cheney DL, Marler P. Vervet Monkey Alarm Calls: Semantic communication in a Free-Ranging Primate. Animal Behaviour. 1980, 28 (4): 1070–1094. doi:10.1016/S0003-3472(80)80097-2.
- Zuberbühler K. Predator-specific alarm calls in Campbell's monkeys, Cercopithecus campbelli. Behavioral Ecology and Sociobiology. 2001, 50 (5): 414–442. JSTOR 4601985. doi:10.1007/s002650100383.
- Slabbekoorn H, Smith TB. Bird song, ecology and speciation. Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences. April 2002, 357 (1420): 493–503. PMC 1692962. PMID 12028787. doi:10.1098/rstb.2001.1056.
- Bannister JL. Baleen Whales (Mysticetes). (编) F Perrin W, Würsig B, Thewissen JG. Encyclopedia of Marine Mammals 2. Academic Press. 2008: 80–89. ISBN 978-0-12-373553-9.
- Norris S. Creatures of Culture? Making the Case for Cultural Systems in Whales and Dolphins (PDF). BioScience. 2002, 52 (1): 9–14. doi:10.1641/0006-3568(2002)052[0009:COCMTC]2.0.CO;2.
- Boughman JW. Vocal learning by greater spear-nosed bats. Proceedings. Biological Sciences. February 1998, 265 (1392): 227–33. PMC 1688873. PMID 9493408. doi:10.1098/rspb.1998.0286.
- Prairie dogs' language decoded by scientists. CBC News. 21 June 2013 [20 May 2015].
- Mayell H. Elephants Call Long-Distance After-Hours. National Geographic. 3 March 2004 [15 November 2016].
- Maynard Smith J, Harper D. Animal Signals. Oxford Series in Ecology and Evolution. Oxford University Press. 2003: 61–63. ISBN 978-0-19-852684-1. OCLC 54460090.
- FitzGibbon CD, Fanshawe JH. Stotting in Thomson's gazelles: an honest signal of condition (PDF). Behavioral Ecology and Sociobiology. 1988, 23 (2): 69–74. doi:10.1007/bf00299889. （原始内容 (PDF)存档于2014-02-25）. 已忽略未知参数
- Bildstein KL. Why White-Tailed Deer Flag Their Tails. The American Naturalist. May 1983, 121 (5): 709–715. JSTOR 2460873. doi:10.1086/284096.
- Gosling LM. A reassessment of the function of scent marking in territories.. Zeitschrift für Tierpsychologie. January 1982, 60 (2): 89–118. doi:10.1111/j.1439-0310.1982.tb00492.x.
- Zala SM, Potts WK, Penn DJ. Scent-marking displays provide honest signals of health and infection.. Behavioral Ecology. March 2004, 15 (2): 338–44. doi:10.1093/beheco/arh022. hdl:10.1093/beheco/arh022. 已忽略未知参数
- Johnson RP. Scent Marking in Mammals. Animal Behaviour. August 1973, 21 (3): 521–535. doi:10.1016/S0003-3472(73)80012-0.
- Schevill WE, McBride AF. Evidence for echolocation by cetaceans. Deep-Sea Research. 1956, 3 (2): 153–154. Bibcode:1956DSR.....3..153S. doi:10.1016/0146-6313(56)90096-x.
- Wilson W, Moss C. Thomas J, 编. Echolocation in Bats and Dolphins. Chicago University Press. 2004: 22. ISBN 978-0-226-79599-7. OCLC 50143737.
- Au WW. The Sonar of Dolphins. Springer-Verlag. 1993. ISBN 978-3-540-97835-0. OCLC 26158593.
- Sanders JG, Beichman AC, Roman J, Scott JJ, Emerson D, McCarthy JJ, Girguis PR. Baleen whales host a unique gut microbiome with similarities to both carnivores and herbivores. Nature Communications. September 2015, 6: 8285. Bibcode:2015NatCo...6.8285S. PMC 4595633. PMID 26393325. doi:10.1038/ncomms9285.
- Speaksman JR. Energetics and the evolution of body size in small terrestrial mammals (PDF). Symposia of the Zoological Society of London. 1996, (69): 69–81.
- Wilson DE, Burnie D (编). Animal: The Definitive Visual Guide to the World's Wildlife 1st. DK Publishing. 2001: 86–89. ISBN 978-0-7894-7764-4. OCLC 46422124.
- Van Valkenburgh B. Deja vu: the evolution of feeding morphologies in the Carnivora. Integrative and Comparative Biology. July 2007, 47 (1): 147–63. PMID 21672827. doi:10.1093/icb/icm016. 已忽略未知参数
- Sacco T, van Valkenburgh B. Ecomorphological indicators of feeding behaviour in the bears (Carnivora: Ursidae). Journal of Zoology. 2004, 263 (1): 41–54. doi:10.1017/S0952836904004856.
- Singer MS, Bernays EA. Understanding omnivory needs a behavioral perspective. Ecology. 2003, 84 (10): 2532–2537. doi:10.1890/02-0397.
- Hutson JM, Burke CC, Haynes G. Osteophagia and bone modifications by giraffe and other large ungulates. Journal of Archaeological Science. 2013-12-01, 40 (12): 4139–4149. doi:10.1016/j.jas.2013.06.004.
- Why Do Cats Eat Grass?. Pet MD. [13 January 2017].
- Geiser F. Metabolic rate and body temperature reduction during hibernation and daily torpor. Annual Review of Physiology. 2004, 66: 239–74. PMID 14977403. doi:10.1146/annurev.physiol.66.032102.115105.
- Humphries MM, Thomas DW, Kramer DL. The role of energy availability in Mammalian hibernation: a cost-benefit approach. Physiological and Biochemical Zoology. 2003, 76 (2): 165–79. PMID 12794670. doi:10.1086/367950.
- Barnes BM. Freeze avoidance in a mammal: body temperatures below 0 degree C in an Arctic hibernator. Science. June 1989, 244 (4912): 1593–5. Bibcode:1989Sci...244.1593B. PMID 2740905. doi:10.1126/science.2740905.
- Geiser F. Aestivation in Mammals and Birds. (编) Navas CA, Carvalho JE. Aestivation: Molecular and Physiological Aspects. Progress in Molecular and Subcellular Biology 49. Springer-Verlag. 2010: 95–113. ISBN 978-3-642-02420-7. doi:10.1007/978-3-642-02421-4.
- Mann J, Patterson EM. Tool use by aquatic animals. Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences. November 2013, 368 (1630): 20120424. PMC 4027413. PMID 24101631. doi:10.1098/rstb.2012.0424.
- Raffaele P. Among the Great Apes: Adventures on the Trail of Our Closest Relatives. New York: Harper. 2011: 83. ISBN 978-0-06-167184-5. OCLC 674694369.
- Köhler W. The Mentality of Apes. Liveright. 1925. ISBN 978-0-87140-108-3. OCLC 2000769.
- McGowan RT, Rehn T, Norling Y, Keeling LJ. Positive affect and learning: exploring the "Eureka Effect" in dogs. Animal Cognition. May 2014, 17 (3): 577–87. PMID 24096703. doi:10.1007/s10071-013-0688-x.
- Karbowski J. Global and regional brain metabolic scaling and its functional consequences. BMC Biology. May 2007, 5 (18): 18. Bibcode:2007arXiv0705.2913K. PMC 1884139. PMID 17488526. arXiv:0705.2913. doi:10.1186/1741-7007-5-18.
- Marino L. Cetacean brains: how aquatic are they?. Anatomical Record. June 2007, 290 (6): 694–700. PMID 17516433. doi:10.1002/ar.20530.
- Gallop GG. Chimpanzees: self-recognition. Science. January 1970, 167 (3914): 86–7. Bibcode:1970Sci...167...86G. PMID 4982211. doi:10.1126/science.167.3914.86.
- Plotnik JM, de Waal FB, Reiss D. Self-recognition in an Asian elephant (PDF). Proceedings of the National Academy of Sciences of the United States of America. November 2006, 103 (45): 17053–7. Bibcode:2006PNAS..10317053P. PMC 1636577. PMID 17075063. doi:10.1073/pnas.0608062103.
- Robert S. Ontogeny of mirror behavior in two species of great apes. American Journal of Primatology. 1986, 10 (2): 109–117. PMID 31979488. doi:10.1002/ajp.1350100202.
- Walraven V, van Elsacker L, Verheyen R. Reactions of a group of pygmy chimpanzees (Pan paniscus) to their mirror images: evidence of self-recognition. Primates. 1995, 36: 145–150. doi:10.1007/bf02381922.
- Leakey R. The Origin of the Mind. The Origin Of Humankind. New York: BasicBooks. 1994: 150. ISBN 978-0-465-05313-1. OCLC 30739453.
- Archer J. Ethology and Human Development. Rowman & Littlefield. 1992: 215–218. ISBN 978-0-389-20996-6. OCLC 25874476.
- Marten K, Psarakos S. Evidence of self-awareness in the bottlenose dolphin (Tursiops truncatus). (编) Parker ST, Mitchell R, Boccia M. Self-awareness in Animals and Humans: Developmental Perspectives. Cambridge: Cambridge University Press. 1995: 361–379. ISBN 978-0-521-44108-7. OCLC 28180680.
- Delfour F, Marten K. Mirror image processing in three marine mammal species: killer whales (Orcinus orca), false killer whales (Pseudorca crassidens) and California sea lions (Zalophus californianus). Behavioural Processes. April 2001, 53 (3): 181–190. PMID 11334706. doi:10.1016/s0376-6357(01)00134-6.
- Jarvis JU. Eusociality in a mammal: cooperative breeding in naked mole-rat colonies. Science. May 1981, 212 (4494): 571–3. Bibcode:1981Sci...212..571J. JSTOR 1686202. PMID 7209555. doi:10.1126/science.7209555.
- Jacobs DS, 等. The colony structure and dominance hierarchy of the Damaraland mole-rat, Cryptomys damarensis (Rodentia: Bathyergidae) from Namibia. Journal of Zoology. 1991, 224 (4): 553–576. doi:10.1111/j.1469-7998.1991.tb03785.x.
- Hardy SB. Mothers and Others: The Evolutionary Origins of Mutual Understanding. Boston: Belknap Press of Harvard University Press. 2009: 92–93.
- Harlow HF, Suomi SJ. Social recovery by isolation-reared monkeys. Proceedings of the National Academy of Sciences of the United States of America. July 1971, 68 (7): 1534–8. Bibcode:1971PNAS...68.1534H. PMC 389234. PMID 5283943. doi:10.1073/pnas.68.7.1534.
- van Schaik CP. The socioecology of fission-fusion sociality in Orangutans. Primates; Journal of Primatology. January 1999, 40 (1): 69–86. PMID 23179533. doi:10.1007/BF02557703.
- Archie EA, Moss CJ, Alberts SC. The ties that bind: genetic relatedness predicts the fission and fusion of social groups in wild African elephants. Proceedings. Biological Sciences. March 2006, 273 (1586): 513–22. PMC 1560064. PMID 16537121. doi:10.1098/rspb.2005.3361.
- Smith JE, Memenis SK, Holekamp KE. Rank-related partner choice in the fission–fusion society of the spotted hyena (Crocuta crocuta) (PDF). Behavioral Ecology and Sociobiology. 2007, 61 (5): 753–765. doi:10.1007/s00265-006-0305-y. （原始内容 (PDF)存档于2014-04-25）. 已忽略未知参数
- Matoba T, Kutsukake N, Hasegawa T. Hayward M, 编. Head rubbing and licking reinforce social bonds in a group of captive African lions, Panthera leo. PLOS ONE. 2013, 8 (9): e73044. Bibcode:2013PLoSO...873044M. PMC 3762833. PMID 24023806. doi:10.1371/journal.pone.0073044.
- Krützen M, Barré LM, Connor RC, Mann J, Sherwin WB. 'O father: where art thou?'--Paternity assessment in an open fission-fusion society of wild bottlenose dolphins (Tursiops sp.) in Shark Bay, Western Australia. Molecular Ecology. July 2004, 13 (7): 1975–90. PMID 15189218. doi:10.1111/j.1365-294X.2004.02192.x.
- Martin C. The Rainforests of West Africa: Ecology – Threats – Conservation 1. Springer. 1991. ISBN 978-3-0348-7726-8. doi:10.1007/978-3-0348-7726-8.
- le Roux A, Cherry MI, Gygax L. Vigilance behaviour and fitness consequences: comparing a solitary foraging and an obligate group-foraging mammal. Behavioral Ecology and Sociobiology. 5 May 2009, 63 (8): 1097–1107. doi:10.1007/s00265-009-0762-1.
- Palagi E, Norscia I. Samonds KE, 编. The Season for Peace: Reconciliation in a Despotic Species (Lemur catta). PLOS ONE. 2015, 10 (11): e0142150. Bibcode:2015PLoSO..1042150P. PMC 4646466. PMID 26569400. doi:10.1371/journal.pone.0142150.
- East ML, Hofer H. Male spotted hyenas (Crocuta crocuta) queue for status in social groups dominated by females. Behavioral Ecology. 2000, 12 (15): 558–568. doi:10.1093/beheco/12.5.558. 已忽略未知参数
- Samuels A, Silk JB, Rodman P. Changes in the dominance rank and reproductive behavior of male bonnet macaques (Macaca radiate). Animal Behaviour. 1984, 32 (4): 994–1003. doi:10.1016/s0003-3472(84)80212-2.
- Delpietro HA, Russo RG. Observations of the common vampire bat (Desmodus rotundus) and the hairy-legged vampire bat (Diphylla ecaudata) in captivity. Mammalian Biology. 2002, 67 (2): 65–78. doi:10.1078/1616-5047-00011.
- Kleiman DG. Monogamy in mammals. The Quarterly Review of Biology. March 1977, 52 (1): 39–69. PMID 857268. doi:10.1086/409721.
- Holland B, Rice WR. Perspective: Chase-Away Sexual Selection: Antagonistic Seduction Versus Resistance (PDF). Evolution; International Journal of Organic Evolution. February 1998, 52 (1): 1–7. JSTOR 2410914. PMID 28568154. doi:10.2307/2410914.
- Clutton-Brock TH. Mammalian mating systems. Proceedings of the Royal Society of London. Series B, Biological Sciences. May 1989, 236 (1285): 339–72. Bibcode:1989RSPSB.236..339C. PMID 2567517. doi:10.1098/rspb.1989.0027.
- Boness DJ, Bowen D, Buhleier BM, Marshall GJ. Mating tactics and mating system of an aquatic-mating pinniped: the harbor seal, Phoca vitulina. Behavioral Ecology and Sociobiology. 2006, 61: 119–130. doi:10.1007/s00265-006-0242-9.
- Klopfer PH. Origins of Parental Care. (编) Gubernick DJ. Parental Care in Mammals. New York: Plenum Press. 1981. ISBN 978-1-4613-3150-6. OCLC 913709574.
- Murthy R, Bearman G, Brown S, Bryant K, Chinn R, Hewlett A, 等. Animals in healthcare facilities: recommendations to minimize potential risks (PDF). Infection Control and Hospital Epidemiology. May 2015, 36 (5): 495–516. PMID 25998315. doi:10.1017/ice.2015.15.
- The Humane Society of the United States. U.S. Pet Ownership Statistics. [27 April 2012].
- USDA. U.S. Rabbit Industry profile (PDF). [10 July 2013]. （原始内容 (PDF)存档于7 August 2019）. 已忽略未知参数
- McKie R. Prehistoric cave art in the Dordogne. The Guardian. 26 May 2013 [9 November 2016].
- Jones J. The top 10 animal portraits in art. The Guardian. 27 June 2014 [24 June 2016].
- Deer Hunting in the United States: An Analysis of Hunter Demographics and Behavior Addendum to the 2001 National Survey of Fishing, Hunting, and Wildlife-Associated Recreation Report 2001-6. Fishery and Wildlife Service (USA). [24 June 2016].
- Shelton L. Recreational Hog Hunting Popularity Soaring. The Natchez Democrat. Gramd View Outdoors. 2014-04-05 [24 June 2016]. （原始内容存档于12 December 2017）. 已忽略未知参数
- Nguyen J, Wheatley R. Hunting For Food: Guide to Harvesting, Field Dressing and Cooking Wild Game. F+W Media. 2015: 6–77. ISBN 978-1-4403-3856-4. Chapters on hunting deer, wild hog (boar), rabbit, and squirrel.
- Horse racing. The Encyclopædia Britannica. [6 May 2014]. （原始内容存档于21 December 2013）.
- Genders R. Encyclopaedia of Greyhound Racing. Pelham Books. 1981. ISBN 978-0-7207-1106-6. OCLC 9324926.
- Plous S. The Role of Animals in Human Society. Journal of Social Issues. 1993, 49 (1): 1–9. doi:10.1111/j.1540-4560.1993.tb00906.x.
- Fowler KJ. Top 10 books about intelligent animals. The Guardian. 26 March 2014 [9 November 2016].
- Gamble N, Yates S. Exploring Children's Literature 2. Los Angeles: Sage. 2008. ISBN 978-1-4129-3013-0. OCLC 71285210.
- Books for Adults. Seal Sitters. [9 November 2016].
- Paterson J. Animals in Film and Media. Oxford Bibliographies. 2013. doi:10.1093/obo/9780199791286-0044.
- Johns C. Cattle: History, Myth, Art. London: The British Museum Press. 2011. ISBN 978-0-7141-5084-0. OCLC 665137673.
- van Gulik RH. Hayagrīva: The Mantrayānic Aspect of Horse-cult in China and Japan. Brill Archive. : 9.
- Grainger R. Lion Depiction across Ancient and Modern Religions. ALERT. 24 June 2012 [November 6, 2016]. （原始内容存档于23 September 2016）. 已忽略未知参数
- Graphic detail Charts, maps and infographics. Counting chickens. The Economist. 27 July 2011 [6 November 2016].
- Breeds of Cattle at CATTLE TODAY. Cattle Today. Cattle-today.com. [November 6, 2016].
- Lukefahr SD, Cheeke PR. Rabbit project development strategies in subsistence farming systems. Food and Agriculture Organization. [November 6, 2016].
- Pond WG. Encyclopedia of Animal Science. CRC Press. 2004: 248–250. ISBN 978-0-8247-5496-9. OCLC 57033325.
- History of Leather. Moore & Giles. [10 November 2016].
- Braaten AW. Wool. (编) Steele V. Encyclopedia of Clothing and Fashion 3. Thomson Gale. 2005: 441–443. ISBN 978-0-684-31394-8. OCLC 963977000.
- Quiggle C. Alpaca: An Ancient Luxury. Interweave Knits. Fall 2000: 74–76.
- Genetics Research. Animal Health Trust. [November 6, 2016]. （原始内容存档于December 12, 2017）. 已忽略未知参数
- Drug Development. Animal Research.info. [November 6, 2016].
- EU statistics show decline in animal research numbers. Speaking of Research. 2013 [November 6, 2016].
- Pilcher HR. It's a knockout. Nature. 2003 [November 6, 2016]. doi:10.1038/news030512-17.
- The supply and use of primates in the EU. European Biomedical Research Association. 1996. （原始内容存档于2012-01-17）.
- Carlsson HE, Schapiro SJ, Farah I, Hau J. Use of primates in research: a global overview. American Journal of Primatology. August 2004, 63 (4): 225–37. PMID 15300710. doi:10.1002/ajp.20054.
- Weatherall D, 等. The use of non-human primates in research (PDF). London, UK: Academy of Medical Sciences. 2006. （原始内容 (PDF)存档于2013-03-23）. 已忽略未知参数
- Diamond JM. Part 2: The rise and spread of food production. Guns, Germs, and Steel: the Fates of Human Societies 1. New York: W.W. Norton & Company. 1997. ISBN 978-0-393-03891-0. OCLC 35792200.
- Larson G, Burger J. A population genetics view of animal domestication (PDF). Trends in Genetics. April 2013, 29 (4): 197–205. PMID 23415592. doi:10.1016/j.tig.2013.01.003.
- Zeder MA. Domestication and early agriculture in the Mediterranean Basin: Origins, diffusion, and impact. Proceedings of the National Academy of Sciences of the United States of America. August 2008, 105 (33): 11597–604. Bibcode:2008PNAS..10511597Z. PMC 2575338. PMID 18697943. doi:10.1073/pnas.0801317105.
- Price E. Principles and applications of domestic animal behavior: an introductory text. Sacramento: Cambridge University Press. 2008. ISBN 978-1-84593-398-2. OCLC 226038028.
- Taupitz J, Weschka M. Chimbrids – Chimeras and Hybrids in Comparative European and International Research. Heidelberg: Springer. 2009: 13. ISBN 978-3-540-93869-9. OCLC 495479133.
- Chambers SM, Fain SR, Fazio B, Amaral M. An account of the taxonomy of North American wolves from morphological and genetic analyses. North American Fauna. 2012, 77: 2. doi:10.3996/nafa.77.0001. 已忽略未知参数
- van Vuure T. Retracing the Aurochs – History, Morphology and Ecology of an extinct wild Ox. Pensoft Publishers. 2005. ISBN 978-954-642-235-4. OCLC 940879282.
- Mooney HA, Cleland EE. The evolutionary impact of invasive species. Proceedings of the National Academy of Sciences of the United States of America. May 2001, 98 (10): 5446–51. Bibcode:2001PNAS...98.5446M. PMC 33232. PMID 11344292. doi:10.1073/pnas.091093398.
- Le Roux JJ, Foxcroft LC, Herbst M, MacFadyen S. Genetic analysis shows low levels of hybridization between African wildcats (Felis silvestris lybica) and domestic cats (F. s. catus) in South Africa. Ecology and Evolution. January 2015, 5 (2): 288–99. PMC 4314262. PMID 25691958. doi:10.1002/ece3.1275.
- Wilson A. Australia's state of the forests report. 2003: 107.
- Rhymer JM, Simberloff D. Extinction by Hybridization and Introgression. Annual Review of Ecology and Systematics. November 1996, 27: 83–109. doi:10.1146/annurev.ecolsys.27.1.83.
- Potts BM. Barbour RC, Hingston AB, 编. Genetic pollution from farm forestry using eucalypt species and hybrids : a report for the RIRDC/L&WA/FWPRDC Joint Venture Agroforestry Program. Rural Industrial Research and Development Corporation of Australia. 2001. ISBN 978-0-642-58336-9. OCLC 48794104.
- Dirzo R, Young HS, Galetti M, Ceballos G, Isaac NJ, Collen B. Defaunation in the Anthropocene (PDF). Science. July 2014, 345 (6195): 401–6. Bibcode:2014Sci...345..401D. PMID 25061202. doi:10.1126/science.1251817.
- Primack R. Essentials of Conservation Biology 6. Sunderland, MA: Sinauer Associates, Inc. Publishers. 2014: 217–245. ISBN 978-1-60535-289-3. OCLC 876140621.
- Vignieri S. Vanishing fauna. Introduction. Science. July 2014, 345 (6195): 392–5. Bibcode:2014Sci...345..392V. PMID 25061199. doi:10.1126/science.345.6195.392. 已忽略未知参数
- Burney DA, Flannery TF. Fifty millennia of catastrophic extinctions after human contact (PDF). Trends in Ecology & Evolution. July 2005, 20 (7): 395–401. PMID 16701402. doi:10.1016/j.tree.2005.04.022. （原始内容 (PDF)存档于2010-06-10）. 已忽略未知参数
- Diamond J. Historic extinctions: a Rosetta stone for understanding prehistoric extinctions. (编) Martin PS, Klein RG. Quaternary extinctions: A prehistoric revolution. Tucson: University of Arizona Press. 1984: 824–862. ISBN 978-0-8165-1100-6. OCLC 10301944.
- Watts J. Human society under urgent threat from loss of Earth's natural life. The Guardian. May 6, 2019 [July 1, 2019].
- McGrath M. Nature crisis: Humans 'threaten 1m species with extinction'. BBC. May 6, 2019 [July 1, 2019].
- Main D. 7 Iconic Animals Humans Are Driving to Extinction. Live Science. 22 November 2013.
- Platt JR. Poachers Drive Javan Rhino to Extinction in Vietnam. Scientific American. 25 October 2011. （原始内容存档于6 April 2015）.
- Estrada A, Garber PA, Rylands AB, Roos C, Fernandez-Duque E, Di Fiore A, 等. Impending extinction crisis of the world's primates: Why primates matter. Science Advances. January 2017, 3 (1): e1600946. Bibcode:2017SciA....3E0946E. PMC 5242557. PMID 28116351. doi:10.1126/sciadv.1600946.
- Fletcher M. Pangolins: why this cute prehistoric mammal is facing extinction. The Telegraph. January 31, 2015.
- Carrington D. Giraffes facing extinction after devastating decline, experts warn. The Guardian. December 8, 2016.
- Pennisi E. People are hunting primates, bats, and other mammals to extinction. Science. October 18, 2016 [3 February 2017].
- Ripple WJ, Abernethy K, Betts MG, Chapron G, Dirzo R, Galetti M, 等. Bushmeat hunting and extinction risk to the world's mammals. Royal Society Open Science. October 2016, 3 (10): 160498. Bibcode:2016RSOS....360498R. PMC 5098989. PMID 27853564. doi:10.1098/rsos.160498. hdl:1893/24446.
- Williams M, Zalasiewicz J, Haff PK, Schwägerl C, Barnosky AD, Ellis EC. The Anthropocene Biosphere. The Anthropocene Review. 2015, 2 (3): 196–219. doi:10.1177/2053019615591020.
- Morell V. Meat-eaters may speed worldwide species extinction, study warns. Science. August 11, 2015 [3 February 2017].
- Machovina B, Feeley KJ, Ripple WJ. Biodiversity conservation: The key is reducing meat consumption. The Science of the Total Environment. December 2015, 536: 419–431. Bibcode:2015ScTEn.536..419M. PMID 26231772. doi:10.1016/j.scitotenv.2015.07.022.
- Carrington D. World on track to lose two-thirds of wild animals by 2020, major report warns. The Guardian. 2016-10-26 [3 February 2017].
- Report 2016: risk and resilience in a new era. Living Planet. World Wildlife Fund: 1–148. ISBN 978-2-940529-40-7. OCLC 961331618.
- Redford KH. The empty forest (PDF). BioScience. 1992, 42 (6): 412–422. JSTOR 1311860. doi:10.2307/1311860.
- Peres CA, Nascimento HS. Impact of Game Hunting by the Kayapo´ of South-eastern Amazonia: Implications for Wildlife Conservation in Tropical Forest Indigenous Reserves. Human Exploitation and Biodiversity Conservation. Topics in Biodiversity and Conservation 3. 2006: 287–313. ISBN 978-1-4020-5283-5. OCLC 207259298.
- Altrichter M, Boaglio G. Distribution and Relative Abundance of Peccaries in the Argentine Chaco: Associations with Human Factors. Biological Conservation. 2004, 116 (2): 217–225. doi:10.1016/S0006-3207(03)00192-7.
- Alverson DL, Freeburg MH, Murawski SA, Pope JG. Bycatch of Marine Mammals. A global assessment of fisheries bycatch and discards. Rome: Food and Agriculture Organization of the United Nations. 1996 . ISBN 978-92-5-103555-9. OCLC 31424005.
- Glowka L, Burhenne-Guilmin F, Synge H, McNeely JA, Gündling L. IUCN environmental policy and law paper. Guide to the Convention on Biodiversity. International Union for Conservation of Nature. 1994. ISBN 978-2-8317-0222-3. OCLC 32201845.
- About IUCN. International Union for Conservation of Nature. 2014-12-03 [3 February 2017].
- Ceballos G, Ehrlich PR, Barnosky AD, García A, Pringle RM, Palmer TM. Accelerated modern human-induced species losses: Entering the sixth mass extinction. Science Advances. June 2015, 1 (5): e1400253. Bibcode:2015SciA....1E0253C. PMC 4640606. PMID 26601195. doi:10.1126/sciadv.1400253.
- Fisher DO, Blomberg SP. Correlates of rediscovery and the detectability of extinction in mammals. Proceedings. Biological Sciences. April 2011, 278 (1708): 1090–7. PMC 3049027. PMID 20880890. doi:10.1098/rspb.2010.1579.
- Ceballos G, Ehrlich AH, Ehrlich PR. The Annihilation of Nature: Human Extinction of Birds and Mammals. Baltimore: Johns Hopkins University Press. 2015: 69. ISBN 978-1-4214-1718-9.
- Zhigang J, Harris RB. Elaphurus davidianus. IUCN Red List of Threatened Species. 2008, 2008 [2012-05-20].old-form url
- McKinney ML, Schoch R, Yonavjak L. Conserving Biological Resources. Environmental Science: Systems and Solutions 5. Jones & Bartlett Learning. 2013. ISBN 978-1-4496-6139-7. OCLC 777948078.
- Perrin WF, Würsig BG, Thewissen JG. Encyclopedia of marine mammals. Academic Press. 2009: 404. ISBN 978-0-12-373553-9. OCLC 455328678.
- Brown WM. Natural selection of mammalian brain components. Trends in Ecology and Evolution. 2001, 16 (9): 471–473. doi:10.1016/S0169-5347(01)02246-7.
- Jaffa Kv, Taher NA. Mammalia Palaestina: The Mammals of Palestine. The Palestinian Biological Bulletin. 2006, (55): 1–46.
- McKenna MC, Bell SK. Classification of Mammals Above the Species Level. New York: Columbia University Press. 1997. ISBN 978-0-231-11013-6. OCLC 37345734.
- Nowak RM. Walker's mammals of the world 6. Baltimore: Johns Hopkins University Press. 1999. ISBN 978-0-8018-5789-8. OCLC 937619124.
- Simpson GG. The principles of classification and a classification of mammals. Bulletin of the American Museum of Natural History. 1945, 85: 1–350.
- Murphy WJ, Eizirik E, O'Brien SJ, Madsen O, Scally M, Douady CJ, 等. Resolution of the early placental mammal radiation using Bayesian phylogenetics. Science. December 2001, 294 (5550): 2348–51. Bibcode:2001Sci...294.2348M. PMID 11743200. doi:10.1126/science.1067179.
- Springer MS, Stanhope MJ, Madsen O, de Jong WW. Molecules consolidate the placental mammal tree (PDF). Trends in Ecology & Evolution. August 2004, 19 (8): 430–8. PMID 16701301. doi:10.1016/j.tree.2004.05.006.
- Vaughan TA, Ryan JM, Capzaplewski NJ. Mammalogy 4. Fort Worth, Texas: Saunders College Publishing. 2000. ISBN 978-0-03-025034-7. OCLC 42285340.
- Kriegs JO, Churakov G, Kiefmann M, Jordan U, Brosius J, Schmitz J. Retroposed elements as archives for the evolutionary history of placental mammals. PLoS Biology. April 2006, 4 (4): e91. PMC 1395351. PMID 16515367. doi:10.1371/journal.pbio.0040091.
- MacDonald DW, Norris S. The Encyclopedia of Mammals 3. London: Brown Reference Group. 2006. ISBN 978-0-681-45659-4. OCLC 74900519.
- Biodiversitymapping.org – All mammal orders in the world with distribution maps
- Paleocene Mammals, a site covering the rise of the mammals, paleocene-mammals.de
- Evolution of Mammals, a brief introduction to early mammals, enchantedlearning.com
- European Mammal Atlas EMMA from Societas Europaea Mammalogica, European-mammals.org
- Marine Mammals of the World – An overview of all marine mammals, including descriptions, both fully aquatic and semi-aquatic, noaa.gov
- Mammalogy.org The American Society of Mammalogists was established in 1919 for the purpose of promoting the study of mammals, and this website includes a mammal image library
[[Category:哺乳類| ]] [[Category:Bathonian first appearances]] [[Category:Extant Middle Jurassic first appearances]] [[Category:卡尔·林奈命名的生物分类]]