108-402: Lemuroidea Lorisoidea (See text) Lemuriformes is the sole extant infraorder of primate that falls under the suborder Strepsirrhini . It includes the lemurs of Madagascar , as well as the galagos and lorisids of Africa and Asia, although a popular alternative taxonomy places the lorisoids in their own infraorder, Lorisiformes. Lemuriform primates are characterized by
216-406: A grooming claw on the foot and a fused row of teeth, a toothcomb , in the bottom jaw. Digital reconstructions of Ida's teeth reveal that she has unerupted molars in her jaw , indicating by comparison with modern squirrel monkeys that she was 9–10 months old and would have weighed 485 grams (17.1 oz); it was also initially suggested that Darwininus reached adulthood at 36 months with
324-493: 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
432-493: 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
540-430: A toothcomb , a specialized set of teeth in the front, lower part of the mouth mostly used for combing fur during grooming. Lemuriform origins are unclear and debated. American paleontologist Philip Gingerich proposed that lemuriform primates evolved from one of several genera of European adapids based on similarities between the front lower teeth of adapids and the toothcomb of extant lemuriforms; however, this view
648-549: A German fossil dealer . Two German museums turned it down as too expensive. A year later at the Hamburg Fossil and Mineral Fair in December 2006, the dealer asked Norwegian vertebrate palaeontologist Jørn Hurum, who had done some previous deals, to discuss something privately. The dealer showed Hurum three high resolution colour photographs of the fossil and told him that the asking price was $ 1 million. Hurum knew that it
756-410: 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
864-477: A body mass of 650–900 grams (23–32 oz), and that it likely had a maximum age of 20 years. Both the age of Ida's death and the possible adult body mass has been questioned by López-Torres and colleagues in 2015, who suggested that Ida would have died between 1.05 and 1.14 years (12 to 14 months) of age based on its dental erruptions resembling more of strepsirrhines , and that an adult Darwinius would have weighed between 622–642 grams (21.9–22.6 oz) based on
972-620: A cercamoniine, but also may have been a stem lemuriform. Azibiids from Algeria date to roughly the same time and may be a sister group of the djebelemurids . Together with Plesiopithecus from the late Eocene Egypt, the three may qualify as the stem lemuriforms from Africa. Molecular clock estimates indicate that lemurs and the lorisoids diverged in Africa during the Paleocene , approximately 62 mya. Between 47 and 54 mya, lemurs dispersed to Madagascar by rafting . In isolation,
1080-585: A complete specimen and arrived at a private Wyoming museum in 1991. Analysis by Jens Franzen of the Natural History Museum of Basel , Switzerland revealed the mixed actual and faked nature of this slab. A comparison of the two slabs indicates that the forger had access to the whole fossil. The primary slab remained in Germany in the possession of a private collector who kept it secret for twenty years before deciding to sell it anonymously via
1188-452: 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
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#17327810603121296-479: 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
1404-439: 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
1512-479: A full cladistic analysis , and in a column in The Times he stated that a unique opportunity to communicate science had been lost, with press releases forestalling the necessary discovery and debate which should now proceed. Hurum considered that the risk of buying the fossil had paid off, and said that "You need an icon or two in a museum to drag people in, this is our Mona Lisa and it will be our Mona Lisa for
1620-474: 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
1728-487: 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 ),
1836-406: A level of secrecy which is hard to attain in modern circumstances. In interviews published on 27 May, Hurum stated that it was good that they had got the message out that primates were rooted deep in time, but that some of the slogans were too much and the publicity got completely out of control. He disclosed that he paid nearly $ 750,000 (£465,000) for the specimen, but felt it was worthwhile to make
1944-435: 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
2052-528: A now-extinct group of strepsirrhines along with a newly discovered 37-million-year-old Egyptian primate, Afradapis . Seiffert believes that characteristics that appeared to show a relationship to haplorrhines are due to convergent evolution and has said that "the PR hype surrounding the Darwinius description was very confusing.” The type specimen is missing only its left rear leg. It has been named Ida after
2160-477: A potential ancestor to humans." Having previously experienced how the blogosphere had picked up on his work, and seen Chinese dinosaur finds the object of bad early descriptions from blogging, Jørn Hurum decided to orchestrate launch of the fossil in a combined scientific and public event. Atlantic Productions , which had cooperated with Hurum on a program on the Predator X , a giant pliosaur from Svalbard ,
2268-422: A report with interviews with Gingerich and with Tim White , who cautioned that "Lemur advocates will be delighted, but tarsier advocates will be underwhelmed". At about the same time a press release headed "World Renowned Scientists Reveal a Revolutionary Scientific Find That Will Change Everything" announced that the find was "lauded as the most significant scientific discovery of recent times." On May 19, 2009
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#17327810603122376-454: A significant transitional form (a "link") between the prosimian and simian ("anthropoid") primate lineages. Others have disagreed with this placement. Concerns have been raised about the claims made about the fossil's relative importance and the publicising of the fossil before adequate information was available for scrutiny by the academic community. Some of Norway's leading biologists, among them Nils Christian Stenseth , have called
2484-664: A sister group to the living strepsirrhines. They are included in Strepsirrhini, and are considered basal members of the clade. Although their status as true primates is not questioned, the questionable relationship between adapiforms and other living and fossil primates leads to multiple classifications within Strepsirrhini. Often, adapiforms are placed in their own infraorder due to anatomical differences with lemuriforms and their unclear relationship. When shared traits with lemuriforms (which may or may not be synapomorphic) are emphasized, they are sometimes reduced to families within
2592-406: A slab and partial counterslab after the amateur excavation and sold separately, was not reassembled until 2007. The fossil is of a juvenile female, approximately 58 cm (23 in) overall length, with the head and body length excluding the tail being about 24 cm (9.4 in). It is estimated that Ida died at about 80–85% of her projected adult body and limb length. The genus Darwinius
2700-628: A themed logo on May 20, 2009. During a ceremony at the American Museum of Natural History Hurum said that "This specimen is like finding the Lost Ark for archeologists" and "It is the scientific equivalent of the Holy Grail . This fossil will probably be the one that will be pictured in all textbooks for the next 100 years." Regarding the publicity, Matt Cartmill an anthropologist from Duke University said "The P.R. campaign on this fossil
2808-460: A transitional fossil (a "missing link") between Strepsirrhini and Haplorrhini, and so could be ancestral to humans. They also suggest that tarsiers have been misplaced in the Haplorrhini and should be considered Strepsirrhini. To support this view they show that as many as six morphological traits found in "Darwinius" are derived characters present only in the Haplorrhini lineage, but absent in
2916-415: 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;
3024-435: 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
3132-504: A wrist injury. Based on studies of ring-tailed lemurs , it is unlikely that this injury was fatal, as ring-tailed lemurs have been shown to survive and maintain their ability to climb with similar or more traumatic injuries. The events regarding the original unearthing of the fossil are not clear, though some facts are known. It was found at the Messel pit in 1983, a disused shale quarry noted for its astonishing fossil preservation, near
3240-465: Is I think more of a story than the fossil itself". Independent experts have raised concern about publicity exaggerating the importance of the find before information was available for scrutiny. Chris Beard, curator of the Carnegie Museum of Natural History , was "awestruck" by the publicity machine but concerned that if the hype was exaggerated, it could damage the popularisation of science if
3348-549: Is a genus within the infraorder Adapiformes , a group of basal strepsirrhine primates from the middle Eocene epoch . Its only known species, Darwinius masillae , lived approximately 47 million years ago ( Lutetian stage ) based on dating of the fossil site. The only known fossil, called Ida , was discovered in 1983 at the Messel pit , a disused quarry near the village of Messel , about 35 km (22 mi) southeast of Frankfurt , Germany. The fossil, divided into
Lemuriformes - Misplaced Pages Continue
3456-659: 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
3564-532: Is from an early group of primates just prior to diversification into the anthropoids (monkeys, apes and humans) and the prosimians (lemurs, lorises and tarsiers). Erik Seiffert and colleagues at Stony Brook University argue that Darwinius is on the branch towards the Strepsirrhini and is not a 'missing link' in the evolution of the Anthropoidea. A phylogenetic analysis of 360 morphological characters in 117 extinct and modern primates places Darwinius in
3672-600: 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
3780-670: 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
3888-501: Is not strongly supported due to a lack of clear transitional fossils. Instead, lemuriforms may be descended from a very early branch of Asian cercamoniines or sivaladapids that immigrated to northern Africa. Scandentia (treeshrews) Dermoptera (colugos) † Plesiadapiformes Haplorhini (tarsiers, monkeys, and apes) † Adapiformes Lorisoids Lemurs Until discoveries of three 40-million-year-old fossil lorisoids ( Karanisia , Saharagalago , and Wadilemur ) in
3996-516: 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
4104-506: 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
4212-595: The El Fayum deposits of Egypt between 1997 and 2005, the oldest known lemuriforms had come from the early Miocene (~20 mya) of Kenya and Uganda . These newer finds demonstrate that lemuriform primates were present during the middle Eocene in Afro-Arabia and that the lemuriform lineage and all other strepsirrhine taxa had diverged before then. Djebelemur from Tunisia dates to the late early or early middle Eocene (52 to 46 mya) and has been considered
4320-508: 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
4428-666: 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 ,
Lemuriformes - Misplaced Pages Continue
4536-591: 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
4644-521: The aye-aye (Daubentoniidae) in its own infraorder, Chiromyiformes. In some cases, plesiadapiforms are included within the order Primates, in which case Euprimates is sometimes treated as a suborder, with Strepsirrhini becoming an infraorder, and the Lemuriformes and others become parvorders. Regardless of the infraordinal taxonomy, crown strepsirrhines are composed of 10 families, three of which are extinct. These three extinct families included
4752-495: The cladistic analysis compared only 30 traits when standard practice is to analyze 200 to 400 traits and to include fossils such as anthropoids from Egypt and the primate genus Eosimias which were not included in the analysis. This contrasts with the motive openly stated by the authors, which was to list 30 anatomical and morphological characteristics "commonly used" to distinguish extant strepsirrhine and haplorrhine primates. Paleontologist Richard Kay of Duke University thought
4860-511: The giant lemurs of Madagascar, many of which died out within the last 1,000 years following human arrival on the island. When Strepsirrhini is divided into two infraorders, the clade containing all toothcombed primates can be called "lemuriforms". When it is divided into three infraorders, the term "lemuriforms" refers only to Madagascar's lemurs, and the toothcombed primates are referred to as either "crown strepsirrhines" or "extant strepsirrhines". Confusion of this specific terminology with
4968-471: 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
5076-416: 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
5184-449: 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
5292-525: 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
5400-709: 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,
5508-482: 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
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#17327810603125616-484: The Eocene adapiforms." In an interview published on 27 May 2009, Jørn Hurum stated that he had an open mind about the possibility that the fossil might turn out to be a lemur and that a paper on systematics to be published within about a year would mainly focus on the partial counterslab containing the inner ear and the foot bones. Most experts hold that the higher primates (simians) evolved from Tarsiidae, branching off
5724-666: The Messel locality that belongs to the cercamoniine adapiforms, in addition to Europolemur koenigswaldi and Europolemur kelleri . Darwinius masillae is similar but not directly related to Godinotia neglecta from Geiseltal . The adapiforms are early primates which are known only from the fossil record, and it is unclear whether they form a monophyletic or a paraphyletic grouping. They are usually grouped under Strepsirrhini —including lemurs , aye-ayes and lorisoids —and as such would not be ancestral to Haplorrhini , which includes tarsiers and simians . Simians are usually called "anthropoid": while this term can be confusing,
5832-559: The Strepsirrhini before the appearance of the Adapiformes. A smaller group agrees with Franzen et al. that the higher primates descend from Adapiformes (Adapoidea). The view of paleontologist Tim White is that Darwinius is unlikely to end the argument. Philip D. Gingerich states that the seven superfamilies of primates are commonly associated in the higher taxonomic groupings of suborders Anthropoidea and Prosimii as an alternative to Haplorhini and Strepsirrhini, depending on
5940-495: The Strepsirrhini lineage, which they interpret as synapomorphies . These include, among others, a cranium with a short rostrum, deep mandibular ramus , loss of all grooming claws. They note "that Darwinius masillae and adapoids contemporary with early tarsioids could represent a stem group from which later anthropoid primates evolved, but we are not advocating this here, nor do we consider either Darwinius or adapoids to be anthropoids." Paleontologists have expressed concern that
6048-551: The UK, directed by Tim Walker and produced by Lucie Ridout, to be screened six days later on the History Channel (US), BBC One (UK), and various stations in Germany and Norway. The New York Daily News noted that "The unveiling of the fossil came as part of an orchestrated publicity campaign unusual for scientific discoveries". One of the paper's co-authors, paleontologist Philip D. Gingerich , expressed dissatisfaction with
6156-417: 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 )
6264-468: 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
6372-526: 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
6480-455: 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,
6588-464: The creature was not all that it was hyped up to be. Paleoanthropologist Elwyn Simons of Duke University stated that it is a wonderful specimen but most of the information had been previously known, and paleoanthropologist Peter Brown of the University of New England said that the paper had insufficient evidence that Darwinius was ancestral to the simians. Others have also criticized claims that
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#17327810603126696-623: The data could have been cherry-picked. Paleontologist Callum Ross of the University of Chicago considered the claim that Darwinius should be classified as haplorhine was "unsupportable in light of modern methods of classification." The opinion of Chris Beard, curator of vertebrate paleontology at the Carnegie Museum of Natural History , was that Darwinius was not a "missing link" between anthropoids and more primitive primates, but that further study of this remarkably complete specimen would be very informative and could reveal relationships amongst "the earliest and least human-like of all known primates,
6804-484: The daughter of Jørn Hurum , the Norwegian vertebrate paleontologist from the Natural History Museum, University of Oslo , who secured one section of the fossil from an anonymous owner and led the research. In addition to the bones, remains of Ida's soft tissue and fur outline are present along with remnants of her last meal of fruit and leaves. The animal is about 58 cm (23 in) from nose to tail, or roughly
6912-455: 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,
7020-564: 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
7128-416: 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
7236-413: The fossil an "exaggerated hoax " and stated that its presentation and popular dissemination "fundamentally violate scientific principles and ethics ." Franzen et al. (2009) place the genus Darwinius in the subfamily Cercamoniinae of the family Notharctidae within the extinct infraorder Adapiformes of early primates . Darwinius masillae is the third primate species to be discovered at
7344-436: The fossil represents the "missing link in human evolution", arguing that there is no such thing unless evolution is visualized as a chain as there are an enormous number of missing branches , and that while the fossil is a primate, there is no evidence to suggest that its species is a direct ancestor of humans. ScienceBlogger Brian Switek questioned the sensationalist coverage of claims of ancestral relationships made before
7452-472: 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
7560-421: 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
7668-460: The general term "strepsirrhine", along with oversimplified anatomical comparisons and vague phylogenetic inferences, can lead to misconceptions about primate phylogeny and misunderstandings about primates from the Eocene, as seen with the media coverage of Darwinius . Because the skeletons of adapiforms share strong similarities with those of lemurs and lorises, researchers have often referred to them as "primitive" strepsirrhines, lemur ancestors, or
7776-550: 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,
7884-430: The growth model of lemurids . The shape of Ida's teeth provides clues as to her diet; jagged molars would have allowed her to slice food, suggesting that she was a leaf and seed eater. This is confirmed by the remarkable preservation of her gut content. Furthermore, the lack of a baculum (penis bone) found in all lower primates means that the fossil was from a female. X-rays performed on Ida revealed that her right wrist
7992-425: 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
8100-464: The infraorder Lemuriformes (or superfamily Lemuroidea). 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
8208-456: 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
8316-460: 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
8424-801: The lemurs diversified and filled the niches often filled by monkeys and apes today. In Africa, the lorises and galagos diverged during the Eocene, approximately 40 mya. Unlike the lemurs in Madagascar, they have had to compete with monkeys and apes, as well as other mammals. Most of the academic literature provides a basic framework for primate taxonomy, usually including several potential taxonomic schemes. Although most experts agree upon phylogeny , many disagree about nearly every level of primate classification. Within Strepsirrhini, two common classifications include either two infraorders (Adapiformes and Lemuriformes) or three infraorders (Adapiformes, Lemuriformes, Lorisiformes). A less common taxonomy places
8532-401: The length of manuscript or number of illustrations, and " PLoS ONE is the quickest way to publish a large work in the world!" At the time its discovery was announced in the scientific and the popular press, the fossil was characterized as the "most complete fossil primate ever discovered"; Sir David Attenborough has described it as "extraordinary". Google commemorated the unveiling with
8640-769: 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
8748-515: The media campaign, telling The Wall Street Journal that they had chosen to publish in PLoS ONE as "There was a TV company involved and time pressure" and they had been pushed to finish the study. "It's not how I like to do science", Gingerich concluded. In an interview, Jørn Hurum said that PLoS ONE had been chosen as it was open access and the research had been funded by Norwegian taxpayers who would benefit from free access, it did not restrict
8856-405: The next 100 years." He has been described as "a modern-era, media-savvy scientist with the right amounts of showmanship, populist sensibility, and disregard for the normal avenues of scientific prestige required to pull this off". The debut in "an astonishingly slick, multi-component media package" required exceptional coordination between networks, museums, producers and scientists while maintaining
8964-445: 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
9072-492: 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
9180-450: The paper uses it, as does associated publicity material. Simians (anthropoids) include monkeys and apes , which in turn includes humans. Franzen et al. in their 2009 paper place Darwinius in the " Adapoidea group of early primates representative of early haplorhine diversification". This means that, according to these authors, the adapiforms would not be entirely within the Strepsirrhini lineage as hitherto assumed, but would qualify as
9288-622: The position of Adapoidea and Tarsioidea. He puts forward a phylogeny in which the higher primates evolved from Darwinius , which he groups with other Adapoidea. He shows the Adapoidea together with the Tarsioidea as representing early diversification of the suborder Haplorhini and shows the Strepsirrhini as having branched off directly from the earliest primates. The Revealing the Link website uses this taxonomic grouping and states that Darwinius
9396-558: The project secret. A deal went through in the summer of 2008 with The History Channel which has been reported as paying more for this than any other documentary. The team decided to publish their findings online in PLoS ONE , an open access journal of the Public Library of Science . The paper for publication was received by PLoS ONE on March 19, 2009 and accepted on May 12, 2009. On 15 May The Wall Street Journal carried
9504-417: 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
9612-618: 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
9720-640: 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
9828-451: 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
9936-414: The size of a small, long-tailed cat. The lemur -like skeleton of the fossil features primate characteristics of grasping hands with opposable thumbs and nails instead of claws. These would have provided a "precision grip" which, for Ida, was useful for climbing and gathering fruit. Ida also has flexible arms and relatively short limbs. The fossil is missing two anatomical features found in modern lemurs:
10044-510: The team revealed their findings to the world at a press conference simultaneously with online publication of the paper in PLoS ONE (for naming purposes, the paper was officially published in print on May 21, 2009). The paper included a statement that the authors were not advocating the possibility that the species could be ancestral to later anthropoid primates; Professor John Fleagle, of Stony Brook University in New York state, asserted that he
10152-608: 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
10260-906: 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
10368-515: 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,
10476-662: The textbooks for the next 100 years" and compared its importance to the Mona Lisa . He also said that Darwinius was "the closest thing we can get to a direct ancestor" and that finding it was "a dream come true". Team member Jens Franzen said the state of preservation was "like the Eighth Wonder of the World", with information "palaeontologists can normally only dream of", but while he said it bore "a close resemblance to ourselves" in some aspects, other features indicated that it
10584-589: 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 . Darwinius Darwinius
10692-473: The village of Messel about 35 km (22 mi) southeast of Frankfurt am Main in Germany . The fossil came as a slab and partial counter slab and was expertly prepared by encasing each slab in resin using the transfer technique necessary to conserve Messel fossils. At some point the slab and counter slab went separate ways. The counter slab was incorporated in a composite of fabricated parts to represent
10800-416: 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
10908-416: Was a primate and according to Tudge's book "was fast concluding that the specimen he was looking at could be one of the holy grails of science — the 'missing link' from the crucial time period." He asked for time until after Christmas to organise funding to pay for the specimen and ensure that it had been legally collected, had an export permit and would be legitimately available for study. His first choice
11016-546: Was brought in on the project in order to "take story straight to the masses in a way that would appeal to the average person, especially kids". The press conference and paper on the fossil was accompanied by the launch of a website the publication of a book which had already been distributed to bookstores, The Link: Uncovering Our Earliest Ancestor by Colin Tudge , and the announcement of a documentary ( Uncovering Our Earliest Ancestor: The Link ), made by Atlantic Productions in
11124-418: Was healing from a fracture which may have contributed to her death. The scientists speculate whether she was overcome by carbon dioxide fumes while drinking from the Messel lake. Hampered by her broken wrist, she slipped into unconsciousness, was washed into the lake and sank to the bottom, where unique fossilisation conditions preserved her for 47 million years. The type specimen of D. masillae exhibits
11232-407: Was named in commemoration of the bicentenary of the birth of Charles Darwin , and the species name masillae honors Messel where the specimen was found. The creature appeared superficially similar to a modern lemur . The authors of the paper describing Darwinius classified it as a member of the primate family Notharctidae , subfamily Cercamoniinae , suggesting that it has the status of
11340-458: Was not a direct ancestor. Independent experts were quick to question the claims. Henry Gee , a senior editor at Nature , said the term "missing link" was misleading and that the scientific community would need to evaluate its significance, which was unlikely to match that of Homo floresiensis or feathered dinosaurs . Chris Beard, curator of the Carnegie Museum of Natural History , said he "would be absolutely dumbfounded if it turns out to be
11448-430: Was one of the anonymous scientific reviewers of the paper and that he had explicitly requested before publication that the authors tone down their original claims that the fossil was on the human evolutionary line. At the press conference the fossil was described as the "missing link" in human evolution. Hurum said that “this fossil rewrites our understanding of the evolution of primates...it will probably be pictured in all
11556-544: Was studied in secret for two years by a team of scientists led by Hurum, who was joined by primate evolution expert Professor Philip Gingerich of the University of Michigan and palaeontologists Jens Franzen, who had studied the counter slab, and Jörg Habersetzer of the Senckenberg Museum 's Research Institute. While studies were in progress, negotiations were put in place for a book and with various broadcasters for documentary programs, all of whom agreed to keep
11664-599: Was the Natural History Museum of Oslo, but it was beyond their means and he began to think of other museums with sponsors available. He persuaded the Oslo museum to make half the funding available with the remainder to be paid only after X-ray scans proved conclusively that it was not a fake, a process which took several months. He put together a team including leading German experts on the Messel fossils, ensuring international ownership. After its acquisition it
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