54-530: Strepsirrhini Adapiformes is a group of early primates . Adapiforms radiated throughout much of the northern continental mass (now Europe , Asia and North America ), reaching as far south as northern Africa and tropical Asia. They existed from the Eocene to the Miocene epoch. Some adapiforms resembled living lemurs . Adapiforms are known from the fossil record only, and it is unclear whether they form
108-435: A grooming claw on the second toe of each foot for scratching in areas that are inaccessible to the mouth and tongue. Adapiforms may have had a grooming claw, but there is little evidence of this. The toothcomb consists of either two or four procumbent lower incisors and procumbent lower canine teeth followed by a canine-shaped premolar . It is used to comb the fur during oral grooming. Shed hairs that accumulate between
162-497: A monophyletic or paraphyletic group. When assumed to be a clade , they are usually grouped under the "wet-nosed" taxon Strepsirrhini , which would make them more closely related to the lemurs and less so to the "dry-nosed" Haplorhini taxon that includes monkeys and apes . In 2009, Franzen and colleagues placed the newly described genus Darwinius in the "Adapoidea group of early primates representative of early haplorhine diversification" so that, according to these authors,
216-613: A toothcomb , a specialized set of teeth in the front, lower part of the mouth mostly used for combing fur during grooming . Many of today's living strepsirrhines are endangered due to habitat destruction , hunting for bushmeat , and live capture for the exotic pet trade. Both living and extinct strepsirrhines are behaviorally diverse, although all are primarily arboreal (tree-dwelling). Most living lemuriforms are nocturnal , while most adapiforms were diurnal . Both living and extinct groups primarily fed on fruit , leaves , and insects . The taxonomic name Strepsirrhini derives from
270-619: 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,
324-502: A more specialized and younger branch of adapiform primarily from Europe. Scandentia (treeshrews) Dermoptera (colugos) † Plesiadapiformes Simians Tarsiers † Omomyiformes † Adapiformes Lorisoids Lemurs Lemurs rafted from Africa to Madagascar between 47 and 54 mya, whereas the lorises split from the African galagos around 40 mya and later colonized Asia. The lemuriforms, and particularly
378-459: A new suborder, Simiolemuriformes, to suggest that strepsirrhines are more closely related to simians than tarsiers. However, no clear relationship between the two had been demonstrated by the early 2000s. The idea reemerged briefly in 2009 during the media attention surrounding Darwinius masillae (dubbed "Ida"), a cercamoniine from Germany that was touted as a " missing link between humans and earlier primates" (simians and adapiforms). However,
432-662: 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
486-533: A smaller brain than comparably sized simians , large olfactory lobes for smell, a vomeronasal organ to detect pheromones , and a bicornuate uterus with an epitheliochorial placenta . Their eyes contain a reflective layer to improve their night vision , and their eye sockets include a ring of bone around the eye, but they lack a wall of thin bone behind it. Strepsirrhine primates produce their own vitamin C , whereas haplorhine primates must obtain it from their diets. Lemuriform primates are characterized by
540-429: A specialized dental structure called a "toothcomb", with the exception of the aye-aye, in which the structure has been modified into two continually growing (hypselodont) incisors (or canine teeth ), similar to those of rodents . Often, the toothcomb is incorrectly used to characterize all strepsirrhines. Instead, it is unique to lemuriforms and is not seen among adapiforms. Lemuriforms groom orally, and also possess
594-497: Is a suborder of primates that includes the lemuriform primates, which consist of the lemurs of Madagascar , galagos ("bushbabies") and pottos from Africa , and the lorises from India and southeast Asia . Collectively they are referred to as strepsirrhines. Also belonging to the suborder are the extinct adapiform primates which thrived during the Eocene in Europe, North America, and Asia, but disappeared from most of
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#1732791112036648-409: Is a synapomorphy (shared, derived trait) seen among lemuriforms, although it is frequently and incorrectly used to define the strepsirrhine clade. Strepsirrhine primates are also united in possessing an epitheliochorial placenta . Unlike the tarsiers and simians, strepsirrhines are capable of producing their own vitamin C and do not need it supplied in their diet. Further genetic evidence for
702-474: Is still used to illustrate the behavioral ecology of tarsiers relative to the other primates. In addition to the controversy over tarsiers, the debate over the origins of simians once called the strepsirrhine clade into question. Arguments for an evolutionary link between adapiforms and simians made by paleontologists Gingerich, Elwyn L. Simons , Tab Rasmussen , and others could have potentially excluded adapiforms from Strepsirrhini. In 1975, Gingerich proposed
756-720: The Greek στρέψις strepsis "a turning round" and ῥίς rhis "nose, snout, (in pl.) nostrils" ( GEN ῥινός rhinos ), which refers to the appearance of the sinuous (comma-shaped) nostrils on the rhinarium or wet nose. The name was first used by French naturalist Étienne Geoffroy Saint-Hilaire in 1812 as a subordinal rank comparable to Platyrrhini ( New World monkeys ) and Catarrhini ( Old World monkeys ). In his description , he mentioned " Les narines terminales et sinueuses " ("Nostrils terminal and winding"). When British zoologist Reginald Innes Pocock revived Strepsirrhini and defined Haplorhini in 1918, he omitted
810-472: The Northern Hemisphere as the climate cooled. Adapiforms are sometimes referred to as being "lemur-like", although the diversity of both lemurs and adapiforms does not support this comparison. Strepsirrhines are defined by their "wet" (moist) rhinarium (the tip of the snout) – hence the colloquial but inaccurate term "wet-nosed" – similar to the rhinaria of canines and felines. They also have
864-505: The toothcomb of extant lemuriforms; however, this view 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 migrated to northern Africa. Until discoveries of three 40 million-year-old fossil lorisoids ( Karanisia , Saharagalago , and Wadilemur ) in the El Fayum deposits of Egypt between 1997 and 2005,
918-558: The Adapiformes tree, possibly as sister of a group which include e.g. Aframonius and Notharctidae . The Adapiformes are thus found not to be literally extinct (in the sense of having no living descendants), and becomes a junior synonym to the Strepsirrhini. Below is a simplified cladogram. Haplorrhini Donrussellia provincialis grade of extinct adapiform taxa Crown Strepsirrhini A 2018 study puts Donrussellia as sister to crown primates. Adapiforms belong to
972-465: The Early to Middle Eocene, evidence from genetics and recent fossil finds both suggest they may have been present during the early adaptive radiation . The origin of the earliest primates that the simians and tarsiers both evolved from is a mystery. Both their place of origin and the group from which they emerged are uncertain. Although the fossil record demonstrating their initial radiation across
1026-472: The Northern Hemisphere is very detailed, the fossil record from the tropics (where primates most likely first developed) is very sparse, particularly around the time that primates and other major clades of eutherian mammals first appeared. Lacking detailed tropical fossils, geneticists and primatologists have used genetic analyses to determine the relatedness between primate lineages and
1080-488: The Prosimii-Anthropoidea taxonomy is familiar and frequently seen in the research literature and textbooks. Strepsirrhines are traditionally characterized by several symplesiomorphic (ancestral) traits not shared with the simians, particularly the rhinarium. Other symplesiomorphies include long snouts , convoluted maxilloturbinals , relatively large olfactory bulbs , and smaller brains. The toothcomb
1134-412: 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. The most commonly recurring debate in primatology during the 1970s, 1980s, and early 2000s concerned the phylogenetic position of tarsiers compared to both simians and
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#17327911120361188-478: The adapiforms would not be within the Strepsirrhini lineage as hitherto assumed but qualify as a stem "missing link" between Strepsirrhini and Haplorrhini. However, subsequent analysis on the Darwinius fossil by Erik Seiffert and colleagues rejects this "missing link" idea, classifying Darwinius and other adapiforms within the Strepsirrhini. Boyer et al. found that the crown Strepsirrhini likely emerged deep in
1242-470: The amount of time since they diverged . Using this molecular clock , divergence dates for the major primate lineages have suggested that primates evolved more than 80–90 mya, nearly 40 million years before the first examples appear in the fossil record. The early primates include both nocturnal and diurnal small-bodied species, and all were arboreal, with hands and feet specially adapted for maneuvering on small branches. Plesiadapiforms from
1296-545: 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, Strepsirrhini is composed of three ranked superfamilies and 14 families, seven of which are extinct. Three of these extinct families included
1350-462: The case of lemurs, natural selection has driven this isolated population of primates to diversify significantly and fill a rich variety of ecological niches , despite their smaller and less complex brains compared to simians. The divergence between strepsirrhines, simians, and tarsiers likely followed almost immediately after primates first evolved. Although few fossils of living primate groups – lemuriforms, tarsiers, and simians – are known from
1404-548: The cladistic analysis was flawed and the phylogenetic inferences and terminology were vague. Although the authors noted that Darwinius was not a "fossil lemur", they did emphasize the absence of a toothcomb, which adapiforms did not possess. † Adapiformes stem lemuriforms Daubentoniidae other lemurs lorises galagos Within Strepsirrhini, two common classifications include either two infraorders (Adapiformes and Lemuriformes) or three infraorders (Adapiformes, Lemuriformes, Lorisiformes). A less common taxonomy places
1458-471: The climate cooled: The last of the adapiforms died out at the end of the Miocene (~7 mya). Adapiform primates are extinct strepsirrhines that shared many anatomical similarities with lemurs. They are sometimes referred to as lemur-like primates, although the diversity of both lemurs and adapiforms do not support this analogy. Like the living strepsirrhines, adapiforms were extremely diverse, with at least 30 genera and 80 species known from
1512-562: The early Paleocene are sometimes considered "archaic primates", because their teeth resembled those of early primates and because they possessed adaptations to living in trees, such as a divergent big toe ( hallux ). Although plesiadapiforms were closely related to primates, they may represent a paraphyletic group from which primates may or may not have directly evolved, and some genera may have been more closely related to colugos , which are thought to be more closely related to primates. The first true primates (euprimates) do not appear in
1566-401: The early Eocene, although their most basal members share enough dental similarities to suggest that they diverged during the Paleocene (66–55 mya). 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
1620-635: The extinct adapiforms and the lemuriform primates, which include lemurs and lorisoids ( lorises , pottos , and galagos ). Strepsirrhines diverged from the haplorhine primates near the beginning of the primate radiation between 55 and 90 mya. Older divergence dates are based on genetic analysis estimates, while younger dates are based on the scarce fossil record . Lemuriform primates may have evolved from either cercamoniines or sivaladapids , both of which were adapiforms that may have originated in Asia. They were once thought to have evolved from adapids ,
1674-477: The family Adapidae, which was divided into two or three subfamilies: Adapinae, Notharctinae, and sometimes Sivaladapinae. All North American adapiforms were lumped under Notharctinae, while the Old World forms were usually assigned to Adapinae. Around the 1990s, two distinct groups of European "adapids" began to emerge, based on differences in the postcranial skeleton and the teeth. One of these two European forms
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1728-543: The family Prosimia (Prosimii) in 1811. The use of the tarsier-galago classification continued for many years until 1898, when Dutch zoologist Ambrosius Hubrecht demonstrated two different types of placentation (formation of a placenta ) in the two groups. English comparative anatomist William Henry Flower created the suborder Lemuroidea in 1883 to distinguish these primates from the simians, which were grouped under English biologist St. George Jackson Mivart 's suborder Anthropoidea (=Simiiformes). According to Flower,
1782-482: The fossil record as of the early 2000s. They diversified across Laurasia during the Eocene, some reaching North America via a land bridge . They were among the most common mammals found in the fossil beds from that time. A few rare species have also been found in northern Africa. The most basal of the adapiforms include the genera Cantius from North America and Europe and Donrussellia from Europe. The latter bears
1836-639: The fossil record until the early Eocene (~55 mya), at which point they radiated across the Northern Hemisphere during a brief period of rapid global warming known as the Paleocene–Eocene Thermal Maximum . These first primates included Cantius , Donrussellia , Altanius , and Teilhardina on the northern continents, as well as the more questionable (and fragmentary) fossil Altiatlasius from Paleocene Africa. These earliest fossil primates are often divided into two groups, adapiforms and omomyiforms . Both appeared suddenly in
1890-402: The fossil record without transitional forms to indicate ancestry, and both groups were rich in diversity and were widespread throughout the Eocene. The last branch to develop were the adapiforms, a diverse and widespread group that thrived during the Eocene (56 to 34 million years ago [ mya ]) in Europe, North America, and Asia. They disappeared from most of the Northern Hemisphere as
1944-459: 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
1998-411: The genus Lemur into two genera: Prosimia for the lemurs, colugos, and tarsiers and Tardigradus for the lorises. Ten years later, É. Geoffroy and Georges Cuvier grouped the tarsiers and galagos due to similarities in their hindlimb morphology , a view supported by German zoologist Johann Karl Wilhelm Illiger , who placed them in the family Macrotarsi while placing the lemurs and tarsiers in
2052-673: The infraorder Adapiformes, which contains a single superfamily, Adapoidea . The group also is sometimes treated as a superfamily (Adapoidea) alongside the other living strepsirrhine superfamilies, Lemuroidea (lemurs) and Lorisoidea ( lorises and galagos ). Rose (1995) suggests that early adapiforms and omomyiforms shared a common ancestor dating to the Thanetian age . Strepsirrhini † Adapiformes Lemuriformes (See text) sister: Haplorhini Strepsirrhini or Strepsirhini ( / ˌ s t r ɛ p s ə ˈ r aɪ n i / ; STREP -sə- RY -nee )
2106-428: The infraorder Lemuriformes (or superfamily Lemuroidea). The first fossil primate described was the adapiform Adapis parisiensis by French naturalist Georges Cuvier in 1821, who compared it to a hyrax (" le Daman "), then considered a member of a now obsolete group called pachyderms . It was not recognized as a primate until it was reevaluated in the early 1870s. Originally, adapiforms were all included under
2160-431: The lemuriform divergence from the other primates and the subsequent lemur-lorisoid split both predate the appearance of adapiforms in the early Eocene. New calibration methods may reconcile the discrepancies between the molecular clock and the fossil record, favoring more recent divergence dates. The fossil record suggests that the strepsirrhine adapiforms and the haplorhine omomyiforms had been evolving independently before
2214-585: 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. The taxonomy of strepsirrhines is controversial and has a complicated history. Confused taxonomic terminology and oversimplified anatomical comparisons have created misconceptions about primate and strepsirrhine phylogeny , illustrated by
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2268-407: The lemurs of Madagascar, are often portrayed inappropriately as " living fossils " or as examples of " basal ", or "inferior" primates. These views have historically hindered the understanding of mammalian evolution and the evolution of strepsirrhine traits, such as their reliance on smell ( olfaction ), characteristics of their skeletal anatomy, and their brain size, which is relatively small. In
2322-405: The media attention surrounding the single "Ida" fossil in 2009. Strepsirrhine primates were first grouped under the genus Lemur by Swedish taxonomist Carl Linnaeus in the 10th edition of Systema Naturae published in 1758. At the time, only three species were recognized, one of which (the colugo) is no longer recognized as a primate. In 1785, Dutch naturalist Pieter Boddaert divided
2376-401: The most ancestral traits , so it is often considered a sister group or stem group of the other adapiforms. Adapiforms are often divided into three major groups: The relationship between adapiform and lemuriform primates has not been clearly demonstrated, so the position of adapiforms as a paraphyletic stem group is questionable. Both molecular clock data and new fossil finds suggest that
2430-467: The nose and reinstated the use of the suborder Strepsirrhini, while also moving the tarsiers and the simians into a new suborder, Haplorhini. It was not until 1953, when British anatomist William Charles Osman Hill wrote an entire volume on strepsirrhine anatomy, that Pocock's taxonomic suggestion became noticed and more widely used. Since then, primate taxonomy has shifted between Strepsirrhini-Haplorhini and Prosimii-Anthropoidea multiple times. Most of
2484-483: 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
2538-523: The other prosimians. Tarsiers are most often placed in either the suborder Haplorhini with the simians or in the suborder Prosimii with the strepsirrhines. Prosimii is one of the two traditional primate suborders and is based on evolutionary grades (groups united by anatomical traits) rather than phylogenetic clades, while the Strepsirrhini-Haplorrhini taxonomy was based on evolutionary relationships. Yet both systems persist because
2592-416: The preferred taxonomic division. Yet tarsiers still closely resemble both strepsirrhines and simians in different ways, and since the early split between strepsirrhines, tarsiers and simians is ancient and hard to resolve, a third taxonomic arrangement with three suborders is sometimes used: Prosimii, Tarsiiformes, and Anthropoidea. More often, the term "prosimian" is no longer used in official taxonomy, but
2646-532: The recently extinct 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
2700-411: The relationship between tarsiers and simians as a haplorhine clade is the shared possession of three SINE markers . Because of their historically mixed assemblages which included tarsiers and close relatives of primates, both Prosimii and Strepsirrhini have been considered wastebasket taxa for "lower primates". Regardless, the strepsirrhine and haplorrhine clades are generally accepted and viewed as
2754-441: The second "r" from both ("Strepsi r hini" and "Haplo r hini" instead of "Strepsi rr hini" and "Haplo rr hini"), although he did not remove the second "r" from Platyrrhini or Catarrhini, both of which were also named by É. Geoffroy in 1812. Following Pocock, many researchers continued to spell Strepsirrhini with a single "r" until primatologists Paulina Jenkins and Prue Napier pointed out the error in 1987. Strepsirrhines include
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#17327911120362808-403: The suborder Lemuroidea contained the families Lemuridae (lemurs, lorises, and galagos), Chiromyidae ( aye-aye ), and Tarsiidae (tarsiers). Lemuroidea was later replaced by Illiger's suborder Prosimii. Many years earlier, in 1812, É. Geoffroy first named the suborder Strepsirrhini, in which he included the tarsiers. This taxonomy went unnoticed until 1918, when Pocock compared the structure of
2862-497: The teeth of the toothcomb are removed by the sublingua or "under-tongue". Adapiforms did not possess a toothcomb. Instead, their lower incisors varied in orientation – from somewhat procumbent to somewhat vertical – and the lower canines were projected upwards and were often prominent. Rhinarium Too Many Requests If you report this error to the Wikimedia System Administrators, please include
2916-481: Was identified as cercamoniines, which were allied with the notharctids found mostly in North America, while the other group falls into the traditional adapid classification. The three major adapiform divisions are now typically regarded as three families within Adapiformes (Notharctidae, Adapidae and Sivaladapidae), but other divisions ranging from one to five families are used as well. All lemuriforms possess
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