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67-472: This is an exceptionally wet area of Madagascar. The driest part of the year is from September to December. As the park is accessible only by a three-hour boat journey, the cyclone season (January to March) is best avoided. There are ten lemur species, including the red ruffed lemur , which is native to the peninsula. The island reserve of Nosy Mangabe is one of the best sites in Madagascar to try to glimpse

134-488: A prehensile tail , a trait found only in New World monkeys , particularly atelids , among primates. Lemurs also rely heavily on their sense of smell, a trait shared with most other mammals and early primates, but not with the visually oriented higher primates. This sense of smell is important in terms of marking territory as well as provide an indication of whether or not another lemur is a viable breeding partner. Lemurs are

201-493: A rhinarium (or "wet nose"); a fully functional vomeronasal organ , which detects pheromones ; a postorbital bar and the lack of postorbital closure (a wall of thin bone behind the eye); orbits (bony sockets that enclose the eye) that are not fully facing forward; left and right mandible (lower jaw) bones that are not fully fused; and a small brain-to-body mass ratio . Additional traits shared with other prosimian primates (strepsirrhine primates and tarsiers ) include

268-463: A 2008 study by Boisvert et al. determined that this was mistaken. They discovered that the final bony portion of the fin in Panderichthys is split into at least four fin radials, bones similar to rudimentary fingers. Thus, in the evolution of tetrapods a shift occurred where the outermost rays of the fins were lost and replaced by the inner radials, which evolve into the earliest digits. This change

335-410: A bicornuate (two-horned) uterus and epitheliochorial placentation . Because their thumbs are only pseudo-opposable, making their movement less independent of the other fingers, their hands are less than perfect at grasping and manipulating objects. On their feet, they have a widely abducted hallux (first toe) which facilitates the grasping of tree limbs. A common misconception is that lemurs have

402-452: A different ocean gyre , producing currents that ran counter to what they are today. The ocean currents were shown to be even stronger than today, which would have pushed a raft along faster, shortening the trip to 30 days or less—short enough for a small mammal to survive easily. As the continental plates drifted northward, the currents gradually changed, and by 20 mya the window for oceanic dispersal had closed, effectively isolating

469-479: A diverse group of primates in terms of morphology and physiology. Some lemurs, such as the sportive lemurs and indriids , have longer hind limbs than forelimbs , making them excellent leapers . Indriids also have a specialized digestive system for folivory , exhibiting enlarged salivary glands , a spacious stomach , and an elongated caecum (lower gut) that facilitates fermentation . The hairy-eared dwarf lemur ( Allocebus trichotis ) reportedly has

536-439: A four-tooth toothcomb due to the loss of either a pair of canines or incisors. Because the lower canine is either included in the toothcomb or lost, the lower dentition can be difficult to read, especially since the first premolar (P2) is often shaped like a canine (caniniform) to fill the canine's role. In folivorous (leaf-eating) lemurs, except for indriids, the upper incisors are greatly reduced or absent. Used together with

603-474: A functional strepsirrhine toothcomb. In the case of the aye-aye, the morphology of the deciduous incisors, which are lost shortly after birth, indicates that its ancestors had a toothcomb. These milk teeth are lost shortly after birth and are replaced by open-rooted, continually growing ( hypselodont ) incisors. The toothcomb in lemurs normally consists of six teeth (four incisors and two canines), although indriids, monkey lemurs, and some sloth lemurs only have

670-487: A highly mobile, filiform (filament-shaped) middle finger for extracting food from tiny holes; large, bat -like ears for detecting hollow spaces within trees; and use of self-generated acoustical cues to forage. Lemurs are unusual since they have great variability in their social structure, yet generally lack sexual dimorphism in size and canine tooth morphology. However, some species tend towards having larger females, and two species of true lemur (genus Eulemur ),

737-435: A more thorough analysis. Lemurs vary greatly in size. They include the smallest primates in the world and, until recently, also included some of the largest. They currently range in size from about 30 g (1.1 oz) for Madame Berthe's mouse lemur ( Microcebus berthae ) up to 7–9 kg (15–20 lb) for the indri ( Indri indri ) and diademed sifaka ( Propithecus diadema ). One recently extinct species rivaled

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804-516: A more useful hand. Surgeons did this at the Institute of Reconstructive Plastic Surgery in New York to a 32-year-old man with the initials O. G.. They touched O. G.’s fingers before and after surgery while using MRI brain scans. Before the surgery, the fingers mapped onto his brain were fused close together; afterward, the maps of his individual fingers did indeed separate and take the layout corresponding to

871-401: A mutation can be surgically corrected, and whether such correction is indicated, is case-dependent. For instance the former chess world champion Mikhail Tal lived all his life with only three right-hand fingers. Each finger has an orderly somatotopic representation on the cerebral cortex in the somatosensory cortex area 3b, part of area 1 and a distributed, overlapping representation in

938-473: A normal hand. Two ideas about the homology of arms, hands, and digits exist. Until recently, few transitional forms were known to elaborate on this transition. One particular example is Panderichthys , a coastal fish from the Devonian period 385 million years ago. Prior to 2008, Panderichthys was interpreted as having a fin terminating at a single large plate surrounded by lepidotrichia (fin rays). However,

1005-415: A very long tongue , allowing it to feed on nectar . Likewise, the red-bellied lemur ( Eulemur rubriventer ) has a feathery brush-shaped tongue, also uniquely adapted to feed on nectar and pollen. The aye-aye has evolved some traits that are unique among primates, making it stand out among the lemurs. Such traits include continuously growing, rodent-like front teeth for gnawing through wood and hard seeds;

1072-435: A wide variety of fruits and leaves, while some are specialists. Two species of lemurs may coexist in the same forest due to different diets. Lemur research during the 18th and 19th centuries focused on taxonomy and specimen collection. Modern studies of lemur ecology and behavior did not begin in earnest until the 1950s and 1960s. Initially hindered by political issues on Madagascar during the mid-1970s, field studies resumed in

1139-655: Is basal to all Lemuriformes, and in 2008, Russell Mittermeier, Colin Groves, and others ignored addressing higher-level taxonomy by defining lemurs as monophyletic and containing five living families, including Daubentoniidae. Relationships among lemur families have also proven to be problematic and have yet to be definitively resolved. To further complicate the issue, several Paleogene fossil primates from outside Madagascar, such as Bugtilemur , have been classified as lemurs. However, scientific consensus does not accept these assignments based on genetic evidence, and therefore it

1206-418: Is closer to tetrapods than Tiktaalik . At any rate, it demonstrates that the fish–tetrapod transition was accompanied by significant character incongruence in functionally important structures." Digit-like radials are also known in the rhizodont fish Sauripterus , though this is likely a case of convergent evolution. Elpistostege , a tetrapodomorph fish closely related to Tiktaalik , preserves one of

1273-485: Is consistent with additional evidence from the embryology of actinopterygians , sharks and lungfish . Pre-existing distal radials in these modern fish develop in a very similar way to the digits of tetrapods. Several rows of digit-like distal fin radials are present in Tiktaalik , a much more complete Devonian vertebrate described in 2006. Though frequently described as the missing link between fishes and tetrapods,

1340-712: Is endemic to the park. Three marine parks are included in the Masoala National Park: Tampolo in the West, Ambodilaitry in the South, and Ifaho in the East. These are among the most diverse marine environments in Madagascar and are superb destinations for kayaking and snorkeling . Each year from July to early September, hundreds of humpback whales visit the Antongil Bay during their long migration. The warm protected waters of

1407-595: Is generally accepted that the Malagasy primates are monophyletic. Another area of contention is the relationship between the sportive lemurs and the extinct koala lemurs (Megaladapidae). Formerly grouped in the same family due to similarities in dentition, they are no longer considered to be closely related due to genetic studies. More taxonomic changes have occurred at the genus level, although these revisions have proven more conclusive, often supported by genetic and molecular analysis. The most noticeable revisions included

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1474-670: Is highest in the rainforests of the east coast. Despite their adaptations for weathering extreme adversity, habitat destruction and hunting have resulted in lemur populations declining sharply, and their diversity has diminished, with the recent extinction of at least 17 species in eight genera, known collectively as the subfossil lemurs . Most of the approximately 100 species and subspecies of lemur are either threatened or endangered. Unless trends change, extinctions are likely to continue. Until recently, giant lemurs existed on Madagascar. Now represented only by recent or subfossil remains, they were modern forms that were once part of

1541-516: Is now used in the colloquial sense in reference to all Malagasy primates. Lemur taxonomy is controversial, and not all experts agree, particularly with the recent increase in the number of recognized species. According to Russell Mittermeier , the president of Conservation International (CI), taxonomist Colin Groves , and others, there are nearly 100 recognized species or subspecies of extant (or living) lemur, divided into five families and 15 genera. Because genetic data indicates that

1608-520: Is one of several most distal parts of a limb , such as fingers or toes , present in many vertebrates . Some languages have different names for hand and foot digits (English: respectively " finger " and " toe ", German: "Finger" and "Zeh", French: "doigt" and "orteil"). In other languages, e.g. Arabic , Russian , Polish , Spanish , Portuguese , Italian , Czech , Tagalog , Turkish , Bulgarian , and Persian , there are no specific one-word names for fingers and toes; these are called "digit of

1675-506: Is smaller than that of anthropoid primates. As with all strepsirrhine primates, they have a "wet nose" ( rhinarium ). Lemurs are generally the most social of the strepsirrhine primates, living in groups known as troops. They communicate more with scents and vocalizations than with visual signals. Lemurs have a relatively low basal metabolic rate , and as a result may exhibit dormancy such as hibernation or torpor . They also have seasonal breeding and female social dominance . Most eat

1742-504: The Eocene (56 to 34  mya ) or Paleocene (66 to 56 mya). Adapiforms, however, lack a specialized arrangement of teeth, known as a toothcomb , which nearly all living strepsirrhines possess. A more recent hypothesis is that lemurs descended from lorisoids (loris-like) primates. This is supported by comparative studies of the cytochrome b gene and the presence of the strepsirrhine toothcomb in both groups. Instead of being

1809-657: The International Union for Conservation of Nature (IUCN) considers lemurs to be the world's most endangered mammals, noting that as of 2013 up to 90% of all lemur species confront the threat of extinction in the wild within the next 20 to 25 years. Ring-tailed lemurs are an iconic flagship species . Collectively, lemurs exemplify the biodiverse fauna of Madagascar and have facilitated the emergence of eco-tourism . In addition, conservation organizations increasingly seek to implement community-based approaches to save lemur species and promote sustainability. Carl Linnaeus ,

1876-583: The Mozambique Channel , a deep channel between Africa and Madagascar with a minimum width of about 560 km (350 mi). In 1915, paleontologist William Diller Matthew noted that the mammalian biodiversity on Madagascar (including lemurs) can only be accounted for by random rafting events , where very small populations rafted from nearby Africa on tangled mats of vegetation, which get flushed out to sea from major rivers. This form of biological dispersal can occur randomly over millions of years. In

1943-471: The gorilla in size, at 160–200 kg (350–440 lb) for Archaeoindris fontoynonti . Like all primates, lemurs have five divergent digits with nails (in most cases) on their hands and feet. Most lemurs possess a laterally compressed, elongated nail, called a toilet-claw , on the second toe and use it for scratching and grooming. In addition to the toilet-claw, lemurs share a variety of other traits with other strepsirrhine primates, which include

2010-416: The gray-headed lemur ( E. albocollaris ) and the red lemur ( E. rufus ), exhibit size differences in canine teeth. True lemurs show sexual dichromatism (sexual differences in fur coloration), but the difference between the genders varies from strikingly obvious, as in the blue-eyed black lemur ( E. macaco ), to nearly imperceptible in the case of the common brown lemur ( E. fulvus ). Crypsis , or

2077-416: The supplementary motor area and primary motor area . The somatosensory cortex representation of the hand is a dynamic reflection of the fingers on the external hand: in syndactyly people have a clubhand of webbed, shortened fingers. However, not only are the fingers of their hands fused, but the cortical maps of their individual fingers also form a club hand. The fingers can be surgically divided to make

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2144-449: The toothcomb of most lemurs, the bottom incisors and canine teeth are procumbent (face forward rather than up) and finely spaced, thus providing a tool for either grooming or feeding. For instance, indri use their toothcomb not only for grooming, but also to pry out the large seeds from the tough epicarp of Beilschmiedia fruits, while fork-marked lemurs use their relatively long toothcomb to cut through tree bark to induce

2211-525: The 1940s, American paleontologist George Gaylord Simpson coined the term "sweepstakes hypothesis" for such random events. Rafting has since been the most accepted explanation for the lemur colonization of Madagascar, but until recently, this trip was thought to be very unlikely because strong ocean currents flow away from the island. In January 2010 , a report demonstrated that around 60 mya both Madagascar and Africa were 1,650 km (1,030 mi) south of their present-day positions, placing them in

2278-709: The 1980s. Lemurs are important for research because their mix of ancestral characteristics and traits shared with anthropoid primates can yield insights on primate and human evolution . Most species have been discovered or promoted to full species status since the 1990s; however, lemur taxonomic classification is controversial and depends on which species concept is used. Many lemur species remain endangered due to habitat loss and hunting. Although local traditions, such as fady , generally help protect lemurs and their forests, illegal logging , economic privation and political instability conspire to thwart conservation efforts. Because of these threats and their declining numbers,

2345-482: The 30-gram (1.1 oz) mouse lemur to the 9-kilogram (20 lb) indri . Since the arrival of humans on the island around 2,000 years ago, over a dozen species of " giant lemurs " larger than living lemur species have become extinct, including the gorilla-sized Archaeoindris . Lemurs share many common basal primate traits, such as divergent digits on their hands and feet, and nails instead of claws (in most species). However, their brain-to-body size ratio

2412-417: The adjacent image. Lemur taxonomy has changed significantly since the first taxonomic classification of lemurs by Carl Linnaeus in 1758. One of the greatest challenges has been the classification of the aye-aye, which has been a topic of debate up until very recently. Until Richard Owen published a definitive anatomical study in 1866, early naturalists were uncertain whether the aye-aye (genus Daubentonia )

2479-468: The arrival of humans roughly 1500 to 2000 years ago, lemurs were found all across the island. However, early settlers quickly converted the forests to rice paddies and grassland through slash-and-burn agriculture (known locally as tavy ), restricting lemurs to approximately 10% of the island's area, ~60,000 km (23,000 sq mi). Today, the diversity and complexity of lemur communities increases with floral diversity and precipitation and

2546-526: The aye-aye, and the extinct sloth lemurs , monkey lemurs , and koala lemurs have reduced dentitions, having lost incisors, canines, or premolars. The ancestral deciduous dentition is 2.1.3 2.1.3 , but young indriids, aye-ayes, koala lemurs, sloth lemurs, and probably monkey lemurs have fewer deciduous teeth. There are also noticeable differences in dental morphology and tooth topography between lemurs. Indri , for instance, have teeth that are perfectly adapted for shearing leaves and crushing seeds. In

2613-486: The bay provide an ideal breeding and calving ground for these marine mammals. In June 2007, Masoala was designated as a World Heritage Site as part of a cluster of parks, known collectively as Rainforests of the Atsinanana , that represent the biodiversity of the country's eastern rainforests. The other national parks included are Marojejy , Zahamena , Ranomafana , Andringitra , and Andohahela . During 2009 and 2010,

2680-455: The case of mouse lemurs, the gray mouse lemur ( M. murinus ), golden-brown mouse lemur ( M. ravelobensis ), and Goodman's mouse lemur ( M. lehilahytsara ) were considered the same species until recently, when genetic tests identified them as cryptic species. The lemur dentition is heterodont (having multiple tooth morphologies) and derives from an ancestral primate permanent dentition of 2.1.3.3 2.1.3.3 . Indriids, sportive lemurs,

2747-504: The direct ancestors of lemurs, the adapiforms may have given rise to both the lemurs and lorisoids, a split that would be supported by molecular phylogenetic studies. The later split between lemurs and lorises is thought to have occurred approximately 62 to 65 mya according to molecular studies, although other genetic tests and the fossil record in Africa suggest more conservative estimates of 50 to 55 mya for this divergence. However,

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2814-566: The elusive nocturnal aye-aye . Masoala harbors many other species, such as the Madagascar day gecko , leaf-tailed gecko , chameleons of all sizes, spectacular birds such as the helmet vanga , and rare species such as the red owl and tomato frog . Masoala is also home to the day-flying sunset moth, Chrysiridia rhipheus . The Madagascar serpent-eagle was recently rediscovered here, and exists in healthy populations only in this part of northeast Madagascar. The tree Ephippiandra masoalensis

2881-564: The environment. Lemurs have adapted to fill many open ecological niches since making their way to Madagascar. Their diversity in both behavior and morphology (outward appearance) rivals that of the monkeys and apes found elsewhere in the world. Ranging in size from the 30 g (1.1 oz) Madame Berthe's mouse lemur , the world's smallest primate, to the recently extinct 160–200 kg (350–440 lb) Archaeoindris fontoynonti , lemurs evolved diverse forms of locomotion, varying levels of social complexity, and unique adaptations to

2948-484: The exact relationship between Panderichthys , Tiktaalik , and tetrapods are yet to be fully resolved. Tiktaalik had some features of the forefin more similar to earlier fish, such as a large ulnare and a distinct axis of larger bones down the middle of the fin. According to Boisvert et al. (2008), "It is difficult to say whether this character distribution implies that Tiktaalik is autapomorphic , that Panderichthys and tetrapods are convergent, or that Panderichthys

3015-416: The flow of tree sap . The toothcomb is kept clean by the sublingua or "under-tongue", a specialized structure that acts like a toothbrush to remove hair and other debris. The sublingua extends below the tip of the tongue and is tipped with keratinized , serrated points that rake between the front teeth. Only the aye-aye, the extinct giant aye-aye , and the largest of the extinct giant sloth lemurs lack

3082-466: The founder of modern binomial nomenclature , gave lemurs their name as early as 1758. With his declaration of the genus Lemur in the 10th edition of Systema Naturae , he included three species: Lemur tardigradus (the red slender loris , now known as Loris tardigradus ), Lemur catta (the ring-tailed lemur ), and Lemur volans (the Philippine colugo , now known as Cynocephalus volans ). Although

3149-421: The full range of lemur sizes. Daubentoniidae Lemuridae Indriidae Lepilemuridae Cheirogaleidae Daubentoniidae Lepilemuridae Cheirogaleidae Lemuridae † Megaladapidae Indriidae † Palaeopropithecidae † Archaeolemuridae From a taxonomic standpoint, the term "lemur" originally referred to the genus Lemur , which currently contains only the ring-tailed lemur . The term

3216-550: The gradual split of a broadly defined genus Lemur into separate genera for the ring-tailed lemur , ruffed lemurs , and brown lemurs due to a host of morphological differences. Due to several taxonomic revisions by Russell Mittermeier, Colin Groves, and others, the number of recognized lemur species has grown from 33 species and subspecies in 1994 to approximately 100 in 2008. With continuing cytogenetic and molecular genetic research, as well as ongoing field studies , particularly with cryptic species such as mouse lemurs,

3283-462: The hand" or "digit of the foot" instead. In Japanese , yubi (指) can mean either, depending on context. Humans normally have five digits on each extremity. Each digit is formed by several bones called phalanges , surrounded by soft tissue. Human fingers normally have a nail at the distal phalanx. The phenomenon of polydactyly occurs when extra digits are present; fewer digits than normal are also possible, for instance in ectrodactyly . Whether such

3350-425: The inability of humans to visually distinguish between two or more distinct species, has recently been discovered among lemurs, particularly within the sportive lemurs ( Lepilemur ) and mouse lemurs ( Microcebus ). With sportive lemurs, subspecies were traditionally defined based on slight morphological differences, but new genetic evidence has supported giving full species status to these regional populations. In

3417-456: The island of Madagascar . Most existing lemurs are small, have a pointed snout, large eyes, and a long tail. They chiefly live in trees and are active at night . Lemurs share resemblance with other primates , but evolved independently from monkeys and apes . Due to Madagascar's highly seasonal climate, lemur evolution has produced a level of species diversity rivaling that of any other primate group. Living lemurs range in weight from

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3484-460: The lemurs and the rest of the terrestrial Malagasy fauna from mainland Africa. Isolated on Madagascar with only a limited number of mammalian competitors, the lemurs did not have to compete with other evolving arboreal mammalian groups, such as squirrels . They were also spared from having to compete with monkeys , which evolved later. The intelligence, aggression, and deceptiveness of monkeys gave them an advantage over other primates in exploiting

3551-769: The local climate. Lemurs lack any shared traits that make them stand out from all other primates. Different types of lemurs have evolved unique combinations of unusual traits to cope with Madagascar's harsh, seasonal climate. These traits can include seasonal fat storage, hypometabolism (including torpor and hibernation ), small group sizes, low encephalization (relative brain size), cathemerality (activity both day and night), and strict breeding seasons . Extreme resource limitations and seasonal breeding are also thought to have given rise to three other relatively common lemur traits: female social dominance , sexual monomorphism, and male–male competition for mates involving low levels of agonism , such as sperm competition . Before

3618-399: The most tetrapod-like hands in any prehistoric fish. The hand of Elpisostege had 19 distal fin radials arranged into blocks up to four radials long. These sequential blocks of radials are very similar to digits. Birds and theropod dinosaurs (from which birds evolved) have three digits on their hands. Paradoxically the two digits that are missing are different: the bird hand (embedded in

3685-496: The national park was invaded by thousands of illegal loggers searching for rosewood. Lemur Lemurs ( / ˈ l iː m ər / LEE -mər ; from Latin lemures lit.   ' ghosts ' or ' spirits ' ) are wet-nosed primates of the superfamily Lemuroidea ( / l ɛ m j ʊ ˈ r ɔɪ d i ə / lem-yuurr- OY -dee-ə ), divided into 8 families and consisting of 15 genera and around 100 existing species . They are endemic to

3752-445: The number of recognized lemur species is likely to keep growing. However, the rapid increase in the number of recognized species has had its critics among taxonomists and lemur researchers. Since classifications ultimately depend on the species concept used, conservationists often favor definitions that result in the splitting of genetically distinct populations into separate species to gain added environmental protection. Others favor

3819-484: The oldest lemur fossils on Madagascar are actually subfossils dating to the Late Pleistocene . Once part of the supercontinent Gondwana , the island of Madagascar has been isolated since it broke away from eastern Africa (~160 mya), Antarctica (~80–130 mya), and India (~80–90 mya). Since ancestral lemurs are thought to have originated in Africa around 62 to 65 mya, they must have crossed

3886-417: The recently extinct subfossil lemurs were closely related to living lemurs, an additional three families, eight genera, and 17 species can be included in the total. In contrast, other experts have labeled this as taxonomic inflation , instead preferring a total closer to 50 species. The classification of lemurs within the suborder Strepsirrhini is equally controversial, although most experts agree on

3953-656: The rest of the lemurs were placed in Lemuriformes and the lorisoids in Lorisiformes. Although it is generally agreed that the aye-aye is the most basal member of the lemur clade, the relationship between the other four families is less clear since they diverged during a narrow 10 to 12 million-year window between the Late Eocene (42 mya) and into the Oligocene (30 mya). The two main competing hypotheses are shown in

4020-640: The rich lemur diversity that has evolved in isolation. Some of their adaptations were unlike those seen in their living relatives. All 17 extinct lemurs were larger than the extant (living) forms, some weighing as much as 200 kg (440 lb), and are thought to have been active during the day. Not only were they unlike the living lemurs in both size and appearance, they also filled ecological niches that either no longer exist or are now left unoccupied. Large parts of Madagascar, which are now devoid of forests and lemurs, once hosted diverse primate communities that included more than 20 lemur species covering

4087-451: The same phylogenetic tree . In one taxonomy, the infraorder Lemuriformes contains all living strepsirrhines in two superfamilies, Lemuroidea for all lemurs and Lorisoidea for the lorisoids ( lorisids and galagos). Alternatively, the lorisoids are sometimes placed in their own infraorder, Lorisiformes, separate from the lemurs. In another taxonomy published by Colin Groves, the aye-aye was placed in its own infraorder, Chiromyiformes, while

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4154-599: The term lemur was first intended for slender lorises , it was soon limited to the endemic Malagasy primates, which have been known as collectively "lemurs" ever since. The name lemur is derived from the Latin term lemures , which refers to specters or ghosts that were exorcised during the Lemuria festival of ancient Rome. Linnaeus was familiar with the works of Virgil and Ovid , both of whom mentioned lemures. Seeing an analogy that fit with his naming scheme, he adapted

4221-906: The term lemur was selected because of the nocturnal activity and slow movements of the red slender loris: Lemures dixi hos, quod noctu imprimis obambulant, hominibus quodanmodo similes, & lento passu vagantur. I call them lemurs, because they go around mainly by night, in a certain way similar to humans, and roam with a slow pace. Lemurs are primates belonging to the suborder Strepsirrhini . Like other strepsirrhine primates , such as lorises , pottos , and galagos , they share ancestral (or plesiomorphic ) traits with early primates. In this regard, lemurs are popularly confused with ancestral primates; however, lemurs did not give rise to monkeys and apes ( simians ). Instead, they evolved independently in isolation on Madagascar . All modern strepsirrhines including lemurs are traditionally thought to have evolved from early primates known as adapiforms during

4288-515: The term "lemur" for these nocturnal primates. It was noted in 2012 that many sources had commonly and falsely assumed that Linnaeus was referring to the ghost-like appearance, reflective eyes , and ghostly cries of Madagascar's lemurs when he selected the name. Up until then, it had also been speculated that Linnaeus may also have known that some Malagasy people believed that lemurs were the souls of their ancestors . However, both claims were discredited since according to Linnaeus' own explanation,

4355-592: The toothcomb on the mandible (lower jaw), this complex is reminiscent of an ungulate browsing pad . Lemurs are unusual among primates for their rapid dental development, particularly among the largest species. For example, indriids have relatively slow body growth but extremely fast tooth formation and eruption . By contrast, anthropoid primates exhibit slower dental development with increased size and slower morphological development. Lemurs are also dentally precocious at birth, and have their full permanent dentition at weaning . Digit (anatomy) A digit

4422-520: The wing) is thought to derive from the second, third and fourth digits of the ancestral five-digit hand. In contrast, the theropod dinosaurs seem to have the first, second and third digits. Recently a Jurassic theropod intermediate fossil Limusaurus has been found in the Junggar Basin in western China that has a complex mix: it has a first digit stub and full second, third and fourth digits but its wrist bones are like those that are associated with

4489-416: Was a primate , rodent , or marsupial . However, the placement of the aye-aye within the order Primates remained problematic until very recently. Based on its anatomy, researchers have found support for classifying the genus Daubentonia as a specialized indriid , a sister group to all strepsirrhines, and as an indeterminate taxon within the order Primates. Molecular tests have now shown Daubentoniidae

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