77-666: Onychonycteris is the more primitive of the three oldest bats known from complete skeletons, having lived in the area that is current day Wyoming during the Eocene period, 52.5 million years ago. Two specimens of Onychonycteris were found in the Green River Formation in 2003, and placed in a new family when the discovery was published in Nature , in February 2008. Onychonycteris means "clawed bat", in reference to
154-973: A 2005 DNA study. A 2013 phylogenomic study supported the two new proposed suborders. Yangochiroptera (as above) [REDACTED] Pteropodidae (megabats) [REDACTED] Megadermatidae (false vampire bats) [REDACTED] horseshoe bats and allies [REDACTED] The 2003 discovery of an early fossil bat from the 52-million-year-old Green River Formation , Onychonycteris finneyi , indicates that flight evolved before echolocative abilities. Onychonycteris had claws on all five of its fingers, whereas modern bats have at most two claws on two digits of each hand. It also had longer hind legs and shorter forearms, similar to climbing mammals that hang under branches, such as sloths and gibbons . This palm-sized bat had short, broad wings, suggesting that it could not fly as fast or as far as later bat species. Instead of flapping its wings continuously while flying, Onychonycteris probably alternated between flaps and glides in
231-510: A fact that still casts a degree of uncertainty on the results of both studies. It is unknown whether Onychonycteris had the large eyes of most nocturnal animals as specimens with intact eye sockets have yet to be found. A lack of enlarged eyes would indicate that this species may have been diurnal, solving the problem of how primitive bats evolved flight without the ability to navigate at night using echolocation. Onychonycteris occurs alongside Icaronycteris index , previously thought to be
308-556: A functional and evolutionary intermediate between gliding and powered flight. Onychonycteris finneyi was the strongest evidence so far in the debate on whether bats developed echolocation before or after they evolved the ability to fly. O. finneyi had well-developed wings, and could clearly fly, but lacked the enlarged cochlea of all extant echolocating bats, closely resembling the old world fruit bats which do not echolocate. This indicates that early bats could fly before they could echolocate. However, an independent evaluation of
385-426: A ground-level take off. Myzopodidae Emballonuridae Nycteridae Mystacinidae Mormoopidae Megabat Pteropidae (Gray, 1821) Pteropodina C. L. Bonaparte , 1837 Megabats constitute the family Pteropodidae of the order Chiroptera ( bats ). They are also called fruit bats , Old World fruit bats , or—especially the genera Acerodon and Pteropus — flying foxes . They are
462-492: A large surface area for the absorption of nutrients. Like all bats, megabats have much smaller genomes than other mammals. A 2009 study of 43 megabat species found that their genomes ranged from 1.86 picograms (pg, 978 Mbp per pg) in the straw-colored fruit bat to 2.51 pg in Lyle's flying fox ( Pteropus lylei ). All values were much lower than the mammalian average of 3.5 pg. Megabats have even smaller genomes than microbats, with
539-437: A longer snout, the skull is usually arched. In genera with shorter faces ( Penthetor , Nyctimene , Dobsonia , and Myonycteris ), the skull has little to no bending. The number of teeth varies among megabat species; totals for various species range from 24 to 34. All megabats have two or four each of upper and lower incisors , with the exception Bulmer's fruit bat ( Aproteles bulmerae ), which completely lacks incisors, and
616-758: A low reproductive output. Most species have one offspring at a time after a pregnancy of four to six months. This low reproductive output means that after a population loss their numbers are slow to rebound. A quarter of all species are listed as threatened , mainly due to habitat destruction and overhunting . Megabats are a popular food source in some areas, leading to population declines and extinction. They are also of interest to those involved in public health as they are natural reservoirs of several viruses that can affect humans. Pteropodinae Nyctimeninae Cynopterinae Eidolinae Scotonycterini Eonycterini Rousettini Stenonycterini Plerotini Myonycterini Epomophorini The family Pteropodidae
693-532: A lung volume of 0.03 cm per gram of body weight (0.05 in per ounce of body weight), species such as the Wahlberg's epauletted fruit bat ( Epomophorus wahlbergi ) have lung volumes 4.3 times greater at 0.13 cm per gram (0.22 in per ounce). Megabats have rapid digestive systems, with a gut transit time of half an hour or less. The digestive system is structured to a herbivorous diet sometimes restricted to soft fruit or nectar. The length of
770-679: A mean respiratory exchange ratio (carbon dioxide produced:oxygen used) of approximately 0.78. Among these two species, the gray-headed flying fox ( Pteropus poliocephalus ) and the Egyptian fruit bat ( Rousettus aegyptiacus ), maximum heart rates in flight varied between 476 beats per minute (gray-headed flying fox) and 728 beats per minute (Egyptian fruit bat). The maximum number of breaths per minute ranged from 163 (gray-headed flying fox) to 316 (straw-colored fruit bat). Additionally, megabats have exceptionally large lung volumes relative to their sizes. While terrestrial mammals such as shrews have
847-558: A mean weight of 2.20 pg compared to 2.58 pg. It was speculated that this difference could be related to the fact that the megabat lineage has experienced an extinction of the LINE1 —a type of long interspersed nuclear element . LINE1 constitutes 15–20% of the human genome and is considered the most prevalent long interspersed nuclear element among mammals. With very few exceptions, megabats do not echolocate , and therefore rely on sight and smell to navigate. They have large eyes positioned at
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#1732773325559924-458: A megabat, weighs only 14.2 g (0.50 oz). The flying foxes of Pteropus and Acerodon are often taken as exemplars of the whole family in terms of body size. In reality, these genera are outliers, creating a misconception of the true size of most megabat species. A 2004 review stated that 28% of megabat species weigh less than 50 g (1.8 oz). Megabats can be distinguished from microbats in appearance by their dog-like faces, by
1001-434: A reduction in the cusps and ridges resulting in a more flattened crown . Like most mammals, megabats are diphyodont , meaning that the young have a set of deciduous teeth (milk teeth) that falls out and is replaced by permanent teeth. For most species, there are 20 deciduous teeth. As is typical for mammals, the deciduous set does not include molars. The scapulae (shoulder blades) of megabats have been described as
1078-425: A thin membrane or patagium . The smallest bat, and arguably the smallest extant mammal , is Kitti's hog-nosed bat , which is 29–34 mm (1.1–1.3 in) in length, 150 mm (5.9 in) across the wings and 2–2.6 g (0.071–0.092 oz) in mass. The largest bats are the flying foxes , with the giant golden-crowned flying fox ( Acerodon jubatus ) reaching a weight of 1.6 kg (3.5 lb) and having
1155-456: A wingspan of 1.7 m (5 ft 7 in). The second largest order of mammals after rodents , bats comprise about 20% of all classified mammal species worldwide, with over 1,400 species. These were traditionally divided into two suborders: the largely fruit-eating megabats , and the echolocating microbats . But more recent evidence has supported dividing the order into Yinpterochiroptera and Yangochiroptera , with megabats as members of
1232-566: Is Icaronycteris gunnelli (52 million years ago), known from two skeletons discovered in Wyoming. The extinct bats Palaeochiropteryx tupaiodon and Hassianycteris kumari , both of which lived 48 million years ago, are the first fossil mammals whose colouration has been discovered: both were reddish-brown. Bats were formerly grouped in the superorder Archonta , along with the treeshrews (Scandentia), colugos (Dermoptera), and primates . Modern genetic evidence now places bats in
1309-701: Is estimated that more than 98% of pteropodid fossil history is missing. Even without fossils, the age and divergence times of the family can still be estimated by using computational phylogenetics . Pteropodidae split from the superfamily Rhinolophoidea (which contains all the other families of the suborder Yinpterochiroptera) approximately 58 Mya (million years ago). The ancestor of the crown group of Pteropodidae, or all living species, lived approximately 31 Mya. The family Pteropodidae likely originated in Australasia based on biogeographic reconstructions . Other biogeographic analyses have suggested that
1386-418: Is estimated that only 12% of bat genera that lived have been found in the fossil record. Most of the oldest known bat fossils were already very similar to modern microbats, such as Archaeopteropus (32 million years ago). The oldest known bat fossils include Archaeonycteris praecursor and Altaynycteris aurora (55-56 million years ago), both known only from isolated teeth. The oldest complete bat skeleton
1463-481: Is incapable of flexion . Megabats' thumbs are longer relative to their forelimbs than those of microbats. Megabats' hindlimbs have the same skeletal components as humans. Most megabat species have an additional structure called the calcar , a cartilage spur arising from the calcaneus . Some authors alternately refer to this structure as the uropatagial spur to differentiate it from microbats' calcars, which are structured differently. The structure exists to stabilize
1540-1147: Is not believed to originate more than 23 mya. Pteropodidae (megabats) [REDACTED] Megadermatidae (false vampire bats) [REDACTED] Craseonycteridae (Kitti's hog-nosed bat) [REDACTED] Rhinopomatidae (mouse-tailed bats) [REDACTED] Hipposideridae (Old World leaf-nosed bats) [REDACTED] Rhinolophidae (horseshoe bats) [REDACTED] Miniopteridae (long winged bat) [REDACTED] Noctilionidae (fisherman bats) [REDACTED] Mormoopidae ( Pteronotus ) [REDACTED] Mystacinidae (New Zealand short-tailed bats) [REDACTED] Thyropteridae (disc-winged bats) Furipteridae [REDACTED] Mormoopidae ( Mormoops ) [REDACTED] Phyllostomidae (New World leaf-nosed bats) [REDACTED] Molossidae (free-tailed bats) [REDACTED] Emballonuridae (sac-winged bats) [REDACTED] Myzopodidae (sucker-footed bats) Emballonuridae ( Taphozous ) [REDACTED] Natalidae (funnel-eared bats) [REDACTED] Vespertilionidae (vesper bats) [REDACTED] Genetic evidence indicates that megabats originated during
1617-465: Is of uncertain placement. Other subfamilies and tribes within Pteropodidae have also undergone changes since Andersen's 1917 publication. In 1997, the pteropodids were classified into six subfamilies and nine tribes based on their morphology , or physical characteristics. A 2011 genetic study concluded that some of these subfamilies were paraphyletic and therefore they did not accurately depict
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#17327733255591694-492: Is poorer than that of humans; at low brightness it is superior. One study that examined the eyes of some Rousettus , Epomophorus , Eidolon , and Pteropus species determined that the first three genera possess a tapetum lucidum , a reflective structure in the eyes that improves vision at low light levels, while the Pteropus species do not. All species examined had retinae with both rod cells and cone cells , but only
1771-701: The Melanesian Islands, including New Guinea , are a plausible candidate for the origin of most megabat subfamilies, with the exception of Cynopterinae; the cynopterines likely originated on the Sunda Shelf based on results of a Weighted Ancestral Area Analysis of six nuclear and mitochondrial genes. From these regions, pteropodids colonized other areas, including continental Asia and Africa. Megabats reached Africa in at least four distinct events. The four proposed events are represented by (1) Scotonycteris , (2) Rousettus , (3) Scotonycterini, and (4)
1848-836: The Middle East before it became more arid at the end of the Miocene. Conversely, they could have reached the continent via the Gomphotherium land bridge , which connected Africa and the Arabian Peninsula to Eurasia . The genus Pteropus (flying foxes), which is not found on mainland Africa, is proposed to have dispersed from Melanesia via island hopping across the Indian Ocean ; this is less likely for other megabat genera, which have smaller body sizes and thus have more limited flight capabilities. Megabats are
1925-495: The Onychonycteris reference fossil in 2010 provided some evidence for other bone structures indicative of laryngeal echolocation, raising the possibility that Onychonycteris finneyi possessed the ability to echolocate after all. They did acknowledge that the fossil itself has been flattened by the fossilization process (a 'pancake fossil'), and thus it was difficult to ascertain the exact bone structure and configuration,
2002-779: The Pteropus species had S-cones, which detect the shortest wavelengths of light; because the spectral tuning of the opsins was not discernible, it is unclear whether the S-cones of Pteropus species detect blue or ultraviolet light. Pteropus bats are dichromatic , possessing two kinds of cone cells. The other three genera, with their lack of S-cones, are monochromatic , unable to see color. All genera had very high densities of rod cells, resulting in high sensitivity to light, which corresponds with their nocturnal activity patterns. In Pteropus and Rousettus , measured rod cell densities were 350,000–800,000 per square millimeter, equal to or exceeding other nocturnal or crepuscular animals such as
2079-617: The São Tomé collared fruit bat ( Myonycteris brachycephala ), which has two upper and three lower incisors. This makes it the only mammal species with an asymmetrical dental formula . All species have two upper and lower canine teeth . The number of premolars is variable, with four or six each of upper and lower premolars. The first upper and lower molars are always present, meaning that all megabats have at least four molars. The remaining molars may be present, present but reduced, or absent. Megabat molars and premolars are simplified, with
2156-708: The house mouse , domestic cat , and domestic rabbit . Megabats use smell to find food sources like fruit and nectar. They have keen senses of smell that rival that of the domestic dog . Tube-nosed fruit bats such as the eastern tube-nosed bat ( Nyctimene robinsoni ) have stereo olfaction , meaning they are able to map and follow odor plumes three-dimensionally. Along with most (or perhaps all) other bat species, megabats mothers and offspring also use scent to recognize each other, as well as for recognition of individuals. In flying foxes, males have enlarged androgen -sensitive sebaceous glands on their shoulders they use for scent-marking their territories, particularly during
2233-542: The monophyly of bats and the single origin of mammal flight. An independent molecular analysis trying to establish the dates when bat ectoparasites ( bedbugs ) evolved came to the conclusion that bedbugs similar to those known today (all major extant lineages, all of which feed primarily on bats) had already diversified and become established over 100 mya (i.e., long before the oldest records for bats, 52 mya), suggesting that they initially all evolved on non-bat hosts and "bats were colonized several times independently, unless
2310-414: The postorbital bar . The snout is simple in appearance and not highly modified, as is seen in other bat families. The length of the snout varies among genera. The premaxilla is well-developed and usually free, meaning that it is not fused with the maxilla ; instead, it articulates with the maxilla via ligaments , making it freely movable. The premaxilla always lack a palatal branch. In species with
2387-462: The "endemic Africa clade", which includes Stenonycterini, Plerotini, Myonycterini, and Epomophorini, according to a 2016 study. It is unknown when megabats reached Africa, but several tribes (Scotonycterini, Stenonycterini, Plerotini, Myonycterini, and Epomophorini) were present by the Late Miocene . How megabats reached Africa is also unknown. It has been proposed that they could have arrived via
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2464-563: The 1997 classification. All species formerly included in Epomophorinae were moved to Rousettinae, which was subdivided into additional tribes. The genus Eidolon , formerly in the tribe Rousettini of Rousettinae, was moved to its own subfamily, Eidolinae . In 1984, an additional pteropodid subfamily, Propottininae, was proposed, representing one extinct species described from a fossil discovered in Africa, Propotto leakeyi . In 2018
2541-762: The ability to sustain heart rates of more than 700 beats per minute, and large lung volumes. Most megabats are nocturnal or crepuscular , although a few species are active during the daytime. During the period of inactivity, they roost in trees or caves. Members of some species roost alone, while others form colonies of up to a million individuals. During the period of activity, they use flight to travel to food resources. With few exceptions, they are unable to echolocate , relying instead on keen senses of sight and smell to navigate and locate food. Most species are primarily frugivorous and several are nectarivorous . Other less common food resources include leaves, pollen, twigs, and bark. They reach sexual maturity slowly and have
2618-545: The above families formerly in Microchiroptera—and Pteropodoidea, which only contains Pteropodidae. In 1917, Danish mammalogist Knud Andersen divided Pteropodidae into three subfamilies: Macroglossinae, Pteropinae (corrected to Pteropodinae ), and Harpyionycterinae. A 1995 study found that Macroglossinae as previously defined, containing the genera Eonycteris , Notopteris , Macroglossus , Syconycteris , Melonycteris , and Megaloglossus ,
2695-539: The absence of the TAS1R1 gene. Among other mammals, only giant pandas have been shown to lack this gene. Megabats also have multiple TAS2R genes, indicating that they can taste bitterness. Megabats, like all bats, are long-lived relative to their size for mammals. Some captive megabats have had lifespans exceeding thirty years. Relative to their sizes, megabats have low reproductive outputs and delayed sexual maturity, with females of most species not giving birth until
2772-426: The age of one or two. Some megabats appear to be able to breed throughout the year, but the majority of species are likely seasonal breeders . Mating occurs at the roost. Gestation length is variable, but is four to six months in most species. Different species of megabats have reproductive adaptations that lengthen the period between copulation and giving birth. Some species such as the straw-colored fruit bat have
2849-551: The air. This suggests that this bat did not fly as much as modern bats, but flew from tree to tree and spent most of its time climbing or hanging on branches. The distinctive features of the Onychonycteris fossil also support the hypothesis that mammalian flight most likely evolved in arboreal locomotors, rather than terrestrial runners. This model of flight development, commonly known as the "trees-down" theory, holds that bats first flew by taking advantage of height and gravity to drop down on to prey, rather than running fast enough for
2926-539: The biggest and most sturdy skeletons. It is also surprising that Pteropodidae are the least represented because they were the first major group to diverge. Several factors could explain why so few pteropodid fossils have been discovered: tropical regions where their fossils might be found are under-sampled relative to Europe and North America; conditions for fossilization are poor in the tropics, which could lead to fewer fossils overall; and even when fossils are formed, they may be destroyed by subsequent geological activity. It
3003-458: The cases of twins, it is rare that both offspring survive. Because megabats, like all bats, have low reproductive rates, their populations are slow to recover from declines. At birth, megabat offspring are, on average, 17.5% of their mother's post-partum weight. This is the smallest offspring-to-mother ratio for any bat family; across all bats, newborns are 22.3% of their mother's post-partum weight. Megabat offspring are not easily categorized into
3080-913: The dichotomy of megabats and microbats did not accurately reflect their evolutionary relationships. Instead of Megachiroptera and Microchiroptera, the study's authors proposed the new suborders Yinpterochiroptera and Yangochiroptera . This classification scheme has been verified several times subsequently and remains widely supported as of 2019. Since 2005, this suborder has alternatively been called "Pteropodiformes". Yinpterochiroptera contained species formerly included in Megachiroptera (all of Pteropodidae), as well as several families formerly included in Microchiroptera: Megadermatidae , Rhinolophidae , Nycteridae , Craseonycteridae , and Rhinopomatidae . Two superfamilies comprise Yinpterochiroptera: Rhinolophoidea—containing
3157-451: The digestive system is short for a herbivore (as well as shorter than those of insectivorous microchiropterans), as the fibrous content is mostly separated by the action of the palate, tongue, and teeth, and then discarded. Many megabats have U-shaped stomachs. There is no distinct difference between the small and large intestine, nor a distinct beginning of the rectum . They have very high densities of intestinal microvilli , which creates
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3234-483: The early Eocene , and belong within the four major lines of microbats. Two new suborders have been proposed; Yinpterochiroptera includes the Pteropodidae , or megabat family, as well as the families Rhinolophidae , Hipposideridae , Craseonycteridae , Megadermatidae , and Rhinopomatidae . Yangochiroptera includes the other families of bats (all of which use laryngeal echolocation), a conclusion supported by
3311-478: The embryo is suspended for up to eight months after implantation in the uterine wall, which is responsible for its very long pregnancies. Shorter gestation lengths are found in the greater short-nosed fruit bat ( Cynopterus sphinx ) with a period of three months. The litter size of all megabats is usually one. There are scarce records of twins in the following species: Madagascan flying fox ( Pteropus rufus ), Dobson's epauletted fruit bat ( Epomops dobsoni ),
3388-662: The evolution of megabats has been determined primarily by genetic data, as the fossil record for this family is the most fragmented of all bats. They likely evolved in Australasia , with the common ancestor of all living pteropodids existing approximately 31 million years ago. Many of their lineages probably originated in Melanesia , then dispersed over time to mainland Asia, the Mediterranean , and Africa . Today, they are found in tropical and subtropical areas of Eurasia, Africa, and Oceania . The megabat family contains
3465-546: The evolutionary origin of bats has been grossly underestimated." Fleas , as a group, are quite old (most flea families formed around the end of the Cretaceous ), but no analyses have provided estimates for the age of the flea lineages associated with bats. The oldest known members of a different lineage of bat ectoparasites ( bat flies ), however, are from roughly 20 mya, well after the origin of bats. The bat-ectoparasitic earwig family Arixeniidae has no fossil record, but
3542-795: The fact that this animal had claws on all five of its digits, whereas modern bats only have claws on the thumb (in most species) or thumb and index finger (in pteropodids ). The specific epithet is a tribute to the fossil prospector and preparator who discovered it, Bonnie Finney. Onychonycteris was unique among bats in that it had claws on all five fingers, as opposed to two or three in all other known species. Its unique limb proportions represent an intermediate between bats and non-flying mammals, with longer hind-limbs and proportionally shorter wings. The aerofoil of O. finneyi lacks any aerodynamic equivalent among known bats, and this aerofoil likely contributed to an undulating flight style that alternated fluttering and gliding. This flight style may represent both
3619-527: The fluttering of wings. Middle English had bakke , most likely cognate with Old Swedish natbakka ( ' night-bat ' ), which may have undergone a shift from -k- to -t- (to Modern English bat ) influenced by Latin blatta , ' moth, nocturnal insect ' . The word bat was probably first used in the early 1570s. The name Chiroptera derives from Ancient Greek : χείρ – cheir , ' hand ' and πτερόν – pteron , ' wing ' . The delicate skeletons of bats do not fossilise well; it
3696-439: The former along with several species of microbats. Many bats are insectivores , and most of the rest are frugivores (fruit-eaters) or nectarivores (nectar-eaters). A few species feed on animals other than insects; for example, the vampire bats feed on blood . Most bats are nocturnal , and many roost in caves or other refuges; it is uncertain whether bats have these behaviours to escape predators . Bats are present throughout
3773-439: The fossils were reexamined and determined to represent a lemur . As of 2018, there were 197 described species of megabat, around a third of which are flying foxes of the genus Pteropus . The fossil record for pteropodid bats is the most incomplete of any bat family. Although the poor skeletal record of Chiroptera is probably from how fragile bat skeletons are, Pteropodidae still have the most incomplete despite generally having
3850-729: The front of their heads. These are larger than those of the common ancestor of all bats, with one study suggesting a trend of increasing eye size among pteropodids. A study that examined the eyes of 18 megabat species determined that the common blossom bat ( Syconycteris australis ) had the smallest eyes at a diameter of 5.03 mm (0.198 in), while the largest eyes were those of large flying fox ( Pteropus vampyrus ) at 12.34 mm (0.486 in) in diameter. Megabat irises are usually brown, but they can be red or orange, as in Desmalopex , Mirimiri , Pteralopex , and some Pteropus . At high brightness levels, megabat visual acuity
3927-477: The gray-headed flying fox, the black flying fox ( Pteropus alecto ), the spectacled flying fox ( Pteropus conspicillatus ), the greater short-nosed fruit bat, Peters's epauletted fruit bat ( Epomophorus crypturus ), the hammer-headed bat, the straw-colored fruit bat, the little collared fruit bat ( Myonycteris torquata ), the Egyptian fruit bat, and Leschenault's rousette ( Rousettus leschenaultii ). In
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#17327733255594004-510: The hind limbs. Additionally, the tail is absent or greatly reduced, with the exception of Notopteris species, which have a long tail. Most megabat wings insert laterally (attach to the body directly at the sides). In Dobsonia species, the wings attach nearer the spine, giving them the common name of "bare-backed" or "naked-backed" fruit bats. Megabats have large orbits , which are bordered by well-developed postorbital processes posteriorly. The postorbital processes sometimes join to form
4081-499: The largest bat species, with individuals of some species weighing up to 1.45 kg (3.2 lb) and having wingspans up to 1.7 m (5.6 ft). Not all megabats are large-bodied; nearly a third of all species weigh less than 50 g (1.8 oz). They can be differentiated from other bats due to their dog-like faces, clawed second digits, and reduced uropatagium . A small number of species have tails. Megabats have several adaptations for flight, including rapid oxygen consumption,
4158-432: The largest, the great flying fox ( Pteropus neohibernicus ), weighs up to 1.6 kg (3.5 lb); some members of Acerodon and Pteropus have wingspans reaching up to 1.7 m (5.6 ft). Despite the fact that body size was a defining characteristic that Dobson used to separate microbats and megabats, not all species of megabat are larger than microbats; the spotted-winged fruit bat ( Balionycteris maculata ),
4235-403: The majority (63%) have fur that is a uniform color, other patterns are seen in this family. These include countershading in four percent of species, a neck band or mantle in five percent of species, stripes in ten percent of species, and spots in nineteen percent of species. Unlike microbats, megabats have a greatly reduced uropatagium , which is an expanse of flight membrane that runs between
4312-528: The mating season. The secretions of these glands vary by species—of the 65 chemical compounds isolated from the glands of four species, no compound was found in all species. Males also engage in urine washing , or coating themselves in their own urine. Megabats possess the TAS1R2 gene, meaning they have the ability to detect sweetness in foods. This gene is present among all bats except vampire bats . Like all other bats, megabats cannot taste umami , due to
4389-429: The mechanisms engaged for flight, allowing them to reduce the additional energy burden of echolocation. Instead of pressurizing a bolus of air for the production of sound, laryngeally echolocating bats likely use the force of the downbeat of their wings to pressurize the air, cutting energetic costs by synchronizing wingbeats and echolocation. The loss of echolocation (or conversely, the lack of its evolution) may be due to
4466-426: The most primitive known bat species, and Icaronycteris gunnelli . Bat (traditional): (present): Bats are flying mammals of the order Chiroptera ( / k aɪ ˈ r ɒ p t ər ə / ). With their forelimbs adapted as wings , they are the only mammals capable of true and sustained flight . Bats are more agile in flight than most birds, flying with their very long spread-out digits covered with
4543-526: The most primitive of any chiropteran family. The shoulder is overall of simple construction, but has some specialized features. The primitive insertion of the omohyoid muscle from the clavicle (collarbone) to the scapula is laterally displaced (more towards the side of the body)—a feature also seen in the Phyllostomidae . The shoulder also has a well-developed system of muscular slips (narrow bands of muscle that augment larger muscles) that anchor
4620-735: The need for pesticides and other insect management measures. They are sometimes numerous enough and close enough to human settlements to serve as tourist attractions, and they are used as food across Asia and the Pacific Rim . However, fruit bats are frequently considered pests by fruit growers. Due to their physiology, bats are one type of animal that acts as a natural reservoir of many pathogens , such as rabies ; and since they are highly mobile, social, and long-lived, they can readily spread disease among themselves. If humans interact with bats, these traits become potentially dangerous to humans. Some bats are also predators of mosquitoes , suppressing
4697-755: The only family of bats incapable of laryngeal echolocation. It is unclear whether the common ancestor of all bats was capable of echolocation, and thus echolocation was lost in the megabat lineage, or multiple bat lineages independently evolved the ability to echolocate (the superfamily Rhinolophoidea and the suborder Yangochiroptera ). This unknown element of bat evolution has been called a "grand challenge in biology". A 2017 study of bat ontogeny (embryonic development) found evidence that megabat embryos at first have large, developed cochlea similar to echolocating microbats, though at birth they have small cochlea similar to non-echolocating mammals. This evidence supports that laryngeal echolocation evolved once among bats, and
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#17327733255594774-408: The only member of the superfamily Pteropodoidea , which is one of two superfamilies in the suborder Yinpterochiroptera . Internal divisions of Pteropodidae have varied since subfamilies were first proposed in 1917. From three subfamilies in the 1917 classification, six are now recognized, along with various tribes . As of 2018, 197 species of megabat had been described. The leading theory of
4851-479: The opposite direction, as in the feet of perching birds. Flight is very energetically expensive, requiring several adaptations to the cardiovascular system . During flight, bats can raise their oxygen consumption by twenty times or more for sustained periods; human athletes can achieve an increase of a factor of twenty for a few minutes at most. A 1994 study of the straw-coloured fruit bat ( Eidolon helvum ) and hammer-headed bat ( Hypsignathus monstrosus ) found
4928-418: The presence of claws on the second digit (see Megabat#Postcrania ), and by their simple ears. The simple appearance of the ear is due in part to the lack of tragi (cartilage flaps projecting in front of the ear canal), which are found in many microbat species. Megabats of the genus Nyctimene appear less dog-like, with shorter faces and tubular nostrils. A 2011 study of 167 megabat species found that while
5005-436: The relationships among megabat species. Three of the subfamilies proposed in 1997 based on morphology received support: Cynopterinae, Harpyionycterinae, and Nyctimeninae. The other three clades recovered in this study consisted of Macroglossini, Epomophorinae + Rousettini, and Pteropodini + Melonycteris . A 2016 genetic study focused only on African pteropodids (Harpyionycterinae, Rousettinae, and Epomophorinae) also challenged
5082-539: The reproductive adaptation of delayed implantation , meaning that copulation occurs in June or July, but the zygote does not implant into the uterine wall until months later in November. The Fischer's pygmy fruit bat ( Haplonycteris fischeri ), with the adaptation of post-implantation delay, has the longest gestation length of any bat species, at up to 11.5 months. The post-implantation delay means that development of
5159-433: The suffix of " Pteropus ". " Pteropus " comes from Ancient Greek pterón meaning "wing" and poús meaning "foot". The Greek word pous of Pteropus is from the stem word pod- ; therefore, Latinizing Pteropus correctly results in the prefix " Pteropod- ". French biologist Charles Lucien Bonaparte was the first to use the corrected spelling Pteropodidae in 1838. In 1875, the zoologist George Edward Dobson
5236-993: The superorder Laurasiatheria , with its sister taxon as Ferungulata , which includes carnivorans , pangolins , odd-toed ungulates , even-toed ungulates , and cetaceans . One study places Chiroptera as a sister taxon to odd-toed ungulates (Perissodactyla). Euarchontoglires (primates, treeshrews, rodents, rabbits) [REDACTED] Eulipotyphla (hedgehogs, shrews, moles, solenodons) [REDACTED] Chiroptera (bats) [REDACTED] Pholidota (pangolins) [REDACTED] Carnivora (cats, hyenas, dogs, bears, seals, weasels) [REDACTED] [REDACTED] Perissodactyla (horses, tapirs, rhinos) [REDACTED] Cetartiodactyla (camels, ruminants, whales) [REDACTED] [REDACTED] The flying primate hypothesis proposed that when adaptations to flight are removed, megabats are allied to primates by anatomical features not shared with microbats and thus flight evolved twice in mammals. Genetic studies have strongly supported
5313-421: The tendon of the occipitopollicalis muscle (muscle in bats that runs from base of neck to the base of the thumb) to the skin. While microbats only have claws on the thumbs of their forelimbs, most megabats have a clawed second digit as well; only Eonycteris , Dobsonia , Notopteris , and Neopteryx lack the second claw. The first digit is the shortest, while the third digit is the longest. The second digit
5390-551: The transmission of mosquito-borne diseases . Depending on the culture, bats may be symbolically associated with positive traits, such as protection from certain diseases or risks, rebirth, or long life, but in the West, bats are popularly associated with darkness, malevolence, witchcraft, vampires , and death. An older English name for bats is flittermouse , which matches their name in other Germanic languages (for example German Fledermaus and Swedish fladdermus ), related to
5467-453: The uncoupling of flight and echolocation in megabats. The larger average body size of megabats compared to echolocating bats suggests a larger body size disrupts the flight-echolocation coupling and made echolocation too energetically expensive to be conserved in megabats. The family Pteropodidae is divided into six subfamilies represented by 46 genera : Family Pteropodidae Megabats take their name from their larger weight and size;
5544-414: The uropatagium, allowing bats to adjust the camber of the membrane during flight. Megabats lacking the calcar or spur include Notopteris , Syconycteris , and Harpyionycteris . The entire leg is rotated at the hip compared to normal mammal orientation, meaning that the knees face posteriorly . All five digits of the foot flex in the direction of the sagittal plane , with no digit capable of flexing in
5621-400: The world, with the exception of extremely cold regions. They are important in their ecosystems for pollinating flowers and dispersing seeds; many tropical plants depend entirely on bats for these services. Bats provide humans with some direct benefits, at the cost of some disadvantages. Bat dung has been mined as guano from caves and used as fertiliser. Bats consume insect pests, reducing
5698-473: Was paraphyletic , meaning that the subfamily did not group all the descendants of a common ancestor. Subsequent publications consider Macroglossini as a tribe within Pteropodinae that contains only Macroglossus and Syconycteris . Eonycteris and Melonycteris are within other tribes in Pteropodinae, Megaloglossus was placed in the tribe Myonycterini of the subfamily Rousettinae, and Notopteris
5775-403: Was first described in 1821 by British zoologist John Edward Gray . He named the family "Pteropidae" (after the genus Pteropus ) and placed it within the now-defunct order Fructivorae. Fructivorae contained one other family, the now-defunct Cephalotidae, containing one genus, Cephalotes (now recognized as a synonym of Dobsonia ). Gray's spelling was possibly based on a misunderstanding of
5852-571: Was lost in pteropodids, rather than evolving twice independently. Megabats in the genus Rousettus are capable of primitive echolocation through clicking their tongues. Some species—the cave nectar bat ( Eonycteris spelaea ), lesser short-nosed fruit bat ( Cynopterus brachyotis ), and the long-tongued fruit bat ( Macroglossus sobrinus )—have been shown to create clicks similar to those of echolocating bats using their wings. Both echolocation and flight are energetically expensive processes. Echolocating bats couple sound production with
5929-459: Was the first to split the order Chiroptera (bats) into two suborders : Megachiroptera (sometimes listed as Macrochiroptera ) and Microchiroptera , which are commonly abbreviated to megabats and microbats. Dobson selected these names to allude to the body size differences of the two groups, with many fruit-eating bats being larger than insect-eating bats. Pteropodidae was the only family he included within Megachiroptera. A 2001 study found that
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