Infraorder
Superfamily
Family
Subfamily
Genus
Lemuriformes
Tarsiiformes
Lemuroidea
Lorisoidea
Tarsioidea
Daubentoniidae
Cheirogaleidae
Lemuridae
Galagidae
Lorisidae
Tarsiidae
Indriidae
Lepilemuridae
Daubentonia
Indri
Propithecus
Avahi
Lepilemur
Mirza
Allocebus
Cheirogaleus
Phaner
Hapalemur
Lemur
Eulemur
Otolemur
Euoticus
Perodicticus
Pseudopotto
Arctocebus
Loris
Tarsius
Microcebus
Varecia
Galago
Nycticebus
Prosimii exhibit the most primitive primate morphology of all primates. Fossil evidence suggests they evolved about 55 Ma, shortly after the first appearance of primates, though their specific origin remains debated. Prosimian features include an unfused mandibular symphysis and frontal bone, a postorbital bar, and a relatively small brain size. Prosimians rely more on smell than sight as indicated by a longer snout, well developed rhinarium, and large olfactory bulbs in the brain. Prosimians have relatively large eyes and a tapetum lucidum in the eye indicating current or ancestral nocturnalism. Most prosimians have a dental formula of 2.1.3.3., procumbent incisors, reduced canines, and a tooth comb.
All strepsirrhines are grouped in the taxonomic infraorder Lemuriformes - one of two infraorders within the taxonomic suborder Prosimii. There are two superfamilies within this infraorder: Lemuroidea and Lorisoidea. The lorises are found on both mainland Africa and in Asia, while the lemurs are restricted to Madagascar.
Citations: Fleagle 1999, Roos et al. 2004, and Stanger-Hall 1997
Tarsiers are specialized small-bodied primates found in Southeast Asia, specifically the Philippines, Borneo, Sumantra, and perhaps Java. Five species are recognized, including: T. spectrum, T. dianae, T. bancanus, T. pumilus, and T. syrichta. Tarsiers share characteristics with both prosimians and anthropoids, and exhibit some of their own derived features. They are well-known for their strikingly large eyes. Additionally, they have hands and feet disproportionately large compared to their small bodies. Tarsiers are completely nocturnal.
Citations: Fleagle 1999
Madagascar separated from mainland African approximately 100 Ma, resulting in the evolution of a diverse group of primates known as Lemurs, or Lemuroidea. This superfamily contains five families: Daubentoniidae, Indriidae, Lepilemuridae, Cheirogaleidae, and Lemuridae. All are found only in Madagascar where they remained relatively undisturbed by human activity until approximately 2000 years ago. Currently, the youngest known lemur fossil dates to only about 1000 years ago. Lemurs all have an unfused mandibular symphysis, a tooth comb, a grooming claw on the second digit, and a bicornuate uterus.
Citations: Fleagle 1999
The superfamily Lorisoidea contains two families: Lorisidae and Galagidae. These two families have radiations that extend beyond Madagascar into mainland Africa and Asia. Both families are nocturnal and arboreal. Their locomotor habits are strikingly different: Lorisidae relies primarily on slow quadrupedalism and climbing; whereas Galagidae are known for their leaping abilities. Unlike many other prosimians, the blood supply to their brain is supplied through the ascending pharyngeal artery rather than through the stapedial. In the auditory region, they also differ in having a tympanic ring fused to the bulla rather than being suspended.
Citations: Fleagle 1999
Tarsiers are well-known for their remarkably large eyes directly related to the lack of a tapetum lucidum. Tarsiers are nocturnal faunivores feeding on insects and small vertebrates. Social systems vary by species, and include solitary with overlapping ranges, family groups with a mated pair and their offspring, and polygynous groups.
Citations: Fleagle 1999
The taxonomic family Daubentoniidae includes a single genus: the Aye-aye, or Daubentonia, a primate with unique morphological specializations. Found in Madagascar, Daubentoniidea exhibit a dental comb and a grooming claw on the second digit of foot common to all strepshirhines. Despite morphological similarities, molecular studies suggest that Daubentoniidea should remain a sister taxa to all other Malagasy primates.
Citations: Fleagle 1999
Cheirogaleidae are the smallest-bodied strepsirrhines. There are five extant genera: Microcebus, Cheirogaleus, Phaner, Allocebus, and Mirza. All members of this family are nocturnal, less than 500 g and build nests. Except for Allocebus, they all have a tympanic ring freely suspended in the bulla. They have an unusual reproductive system, in that females have three pairs of nipples and usually give birth to twins.
Citations: Fleagle 1999, and Pastorini et al. 2001
The family Lemuridae contains four genera: Varecia, Hapalemur, Lemur, and Eulemur. They are found throughout Madagascar. Similar to cheirogaleids, they have a 2.1.3.3. dental formula. They live in groups and are diurnal or cathemeral. All members of this family rely on quadrupedal walking and running, and leaping, to different extents.
Citations: Fleagle 1999
The galagos of the family Galagidae are a diverse group of small-bodied primates that can be found throughout eastern and southern Africa. At least three genera are recognized, including: Otolemur, Galago, and Euoticus. Galagos all are nocturnal and arboreal. The galagos are one of two prosimian families that have geographic distributions on mainland Africa. All galagos have large ears, long hindlimbs, an elongated ankle region, and a long tail. Galagos are known for being exceptional leapers.
Citations: Fleagle 1999
The lorises, of the family Lorisidae, are the most wide-spread prosimian family with genera in both Asia and Africa. Lorises are most apparently distinguished from members of Galagidae by their use of slow, deliberate quadrupedal walking and climbing. Anatomically, they have smaller ears than galagos. They also lack a long tail and have fore- and hind- limbs of nearly equal length.
Citations: Fleagle 1999, and Masters et al. 2006
Tarsiers share characteristics with both prosimians and anthropoids, and exhibit some of their own derived features. As such, their phylogenetic position within the order Primates has been controversial. Tarsiers share a number of features with other prosimians; grooming claws, a bicornate uterus, multiple nipples and an unfused mandibular symphysis. Features shared with anthropoids include a fused frontal, partial post-orbital closure, a dry nose, unattached upper lip, and a promontory blood supply. Features unique to tarsiers include a 2.1.3.3./ 1.1.3.3. dental formula, a fused tibia and a fibula, and a very long ankle (tarsus) region, from which their name is derived.
Citations: Fleagle 1999
The Indriid family contains three genera that vary primarily in body size and activity pattern. The three genera are: Avahi, Propithecus and, Indri. Avahi is the only nocturnal indriid, and it is also the smallest-bodied. All have a reduced dental formula, with only four teeth in their tooth comb and one less premolar in each quadrant. Indriids are known for their specialized leaping abilities. They have long hindlimbs, and a short, dorsally oriented ischium.
Citations: Fleagle 1999
The Lepilemuridae family contains one genus: Lepilemur, or the sportive or weasel lemurs. They are found throughout Madagascar in a variety of forest habitats. They are nocturnal and folivorous. Socially, sportive lemurs are solitary with overlapping ranges. With regard to their anatomy, Lepilemur is characterized by an array of characteristics that distinguish them from lemuriids or indriids. Lepilemur lacks permanent incisors. The cranial articulation with the mandible is unusual. They move primarily by leaping.
Citations: Fleagle 1999
The aye-aye, Daubentonia, is a quadrupedal medium-sized (3kg) nocturnal solitary forager that is found in Madagascar. Daubentonia is perhaps one of the most unique primates, exhibiting extreme morphological specializations. Dentally, aye-ayes have a reduced dental formula, 1.0.1.3., and ever-growing incisors (much like rodents). The digits are clawed (except for the hallux), and the third digit of each hand is elongated. They use this elongated digit to probe for insect larvae, flowers, and plant parts. Like woodpeckers, it taps the trunk of a tree and listens for the responses of potential insect prey inside.
Citations: Fleagle 1999
Indri is found in the rain forests on the eastern coasts of Madagascar. One species is recognized: Indri indri, which is also the largest known Indriid (6.8 kg). They eat young leaves, shoots and fruits; and live in small family groups. Anatomically, they have long hands and feet, slender arms, very long legs, and lack a tail. They move primarily by leaping.
Citations: Fleagle 1999
Sifakas, or Propithecus, are found throughout Madagascar, though geographic region and habitat preferences vary by species. P. diadema is found on the west coast and prefers dry forest, P. diadema is found on the east coast in the rain forests, and P. tattersalli is from a small region in the northeast. All Sifakas are diurnal, vertical clingers and leapers, and feed on leaves and fruit. Anatomically, they have very long legs and a long tail.
Citations: Fleagle 1999
Avahi, the woolly lemur, is found in the wet forests of eastern Madagascar. Two species are recognized: Avahi laniger and Avahi occidentalis. They are the smallest-bodied and only nocturnal indriid, and also more quadrupedal than either Propithecus or Indri. They do, however, leap between supports as well. They live in family groups, and are monogamous.
Citations: Fleagle 1999
Lepilemur, the sportive or weasel lemurs, are found throughout Madagascar in a variety of forest habitats. There are over 20 recognized species. all of which are nocturnal and folivorous. Socially, sportive lemurs are solitary with overlapping ranges. With regard to their anatomy, Lepilemurs have an array of characteristics that distinguish them from lemuriids or indriids. Lepilemur lacks permanent incisors, and the cranial articulation with the mandible is unusual. They move primarily by leaping.
Citations: Fleagle 1999
Coquerel's dwarf lemur, Mirza coquereli, is found on the western and northwestern coasts of Madagascar. Only the one species is recognized. Similar to mouse lemurs, Coquerel's dwarf lemur has a pointed snout. Mirza is an arboreal quadruped that feeds on insects, small vertebrates, fruits and nectars. Socially, males and females are solitary, with their ranges overlapping during mating season.
Citations: Fleagle 1999
The hairy-eared dwarf lemur, Allocebus, is a small-bodied (less than 500 g) cheirogaleid found in Madagascar. They get their name from their ear tufts. Allocebus is distinguished from other cheirogaleids by the morphology of their auditory (ear) region. Allocebus has a tympanic ring that is fused to wall of the bulla instead of a free tympanic ring like other cheirogaleids. Not much is known of its natural behavior.
Citations: Fleagle 1999
Dwarf lemurs (Cheirogaleus) are small-bodied cheirogaleids found in Madagascar. There are two species: C. medius (fat-tailed dwarf lemur) and C. major (greater dwarf lemur). They differ mainly in body size and habitat. C.medius is found in the dry forests of the west and south, while C. major is found in the wetter forests in the east. Both species are predominately frugivorous, and are arboreal quadrupeds. In both species, the snout is pointed, the trunk is long, and their arms are longer than their legs.
Citations: Fleagle 1999
Phaner furcifer, the fork-marked lemur, is the largest-bodied cheirogaleid, and the only species within the genus Phaner. It is found throughout Madagascar, easily identified by the dark rings around the eyes that come together to form a stripe down the back. They have long hindlimbs, and bushy long tails. Dentally, they have procumbent upper and lower incisors, and long narrow tongues used to obtain gums from trees. They are arboreal quadrupeds.
Citations: Fleagle 1999
Hapalemur, or bamboo lemurs, derive their common name from their dietary specialization on bamboo plants. There are three species that differ in habitat and plant part preference. The greater bamboo lemur (H. simus) and the golden bamboo lemur (H. aureus) are both restricted to the southeast rain forests in Madagascar; the former specializes on bamboo pith, while the latter specializes on growing bamboo shoots. The last species, H. griseus (the gray bamboo or gentle lemur) has a broader distribution and specializes on new bamboo shoots. Compared to the other lemurs, they all have short arms and legs. They move both quadrupedally and by clinging and leaping.
Citations: Fleagle 1999
Once a diverse genus, taxonomic studies now limit Lemur to only ring-tailed lemurs including L. catta. Found only in Madagascar, lemurs are usually diurnal, move quadrupedally, and spend more time on the ground than other lemur genera. Diets vary by region, but are based on fruits and leaves. Members of Lemur are typically mid-range in body size.
Citations: Fleagle 1999
Eulemur, is a genus containing several medium-sized (1-4 kg) lemurs that are found throughout Madagascar. Several species are recognized including: E. albifrons (white-fronted lemur), E. albocollaris (white-collared lemur), E. collaris (red-collared lemur), E. coronatus (crowned lemur), E. fulvus (brown lemur), E. macaco (black lemur), E. mongoz (mongoose lemur), E. rubriventer (red-bellied lemur), E. rufus (red-fronted lemur), and E. sanfordi (Sanford's lemur). They all share a 2.1.3.3. dental formula and have a free tympanic ring. Most members of Eulemur move about by quadrupedal walking, running, and some leaping.
Citations: Fleagle 1999
There are at least two recognized species of Otolemur, or Thick-tailed bushbabies: O. crassicaudatus and O. garnettii, found in eastern and southern Africa, and east Africa respectively. As their name suggests, they are the largest bodied bushbabies who are distinguished by their long ears and long tails. The elongated ankle bones and longer hindlimbs than forelimbs are slightly reduced in Otolemur than in other galagos, whose primary form of locomotion is quadrupedal walking and running, with some leaping. They tend to reside in forest habitats where they feed on fruits and gums. Otolemur shows significant sexual dimorphism.
Citations: Fleagle 1999
Euoticus, or the Needle-clawed bushbaby, are found in all canopy levels in African forests, and use quadrupedal and leaping forms of locomotion. Two species are currently recognized: E. elegantulus (southern needle-clawed bushbaby) and E. pallidus (northern needle-clawed bushbaby), though some include E. matschiei in the genus. Euoticus exhibits several specializations including procumbent maxillary incisors, premolars that resemble canines, and nails that resemble claws. The Euoticus diet consists primarily of gums.
Citations: Fleagle 1999
The potto, Perodicticus, is the largest-bodied loris, and has the most widespread geographic range - found from Liberia to Kenya. Pottos are largely frugivorous, but also are known to include some invertebrates. They are largely solitary animals. Like other lorises, pottos are known for their slow, deliberate quadrupedalism and climbing. They also lack long tails.
Citations: Fleagle 1999
Pseudopotto was discovered within the last decade. There is one species, Pseudopotto martini, found in west Africa. Pseudopotto is distinguished from Perodictus in having a smaller body size, a moderate-sized tail, and a reduced third premolar. Little is known about its natural behavior.
Citations: Fleagle 1999
Arctocebus, the angwantibos, are restricted to west central Africa. Two species are recognized: A. calabarensis (angwantibo), and A. aureus(golden angwantibo). They are solitary foragers, and are predominately insectivorous. Specifically, they are known for feeding on noxious caterpillars. Like other lorises, they move by slow, deliberate quadrupedalism and climbing.
Citations: Fleagle 1999
The slender loris, Loris is one of two Asian loris genera, found in Sri Lanka and southern India. One species is recognized: Loris tardigradus. It is known for its extremely slender legs. It prefers the understory of dry forests and the canopy of wet forests. Little is known about its natural behavior.
Citations: Fleagle 1999
Species: T. syrichta, T. bancanus, T. dianae, T. spectrum, T.pumilus
Dental Formula: 2.1.3.3./1.1.3.3.
Body Mass: 0.117 (F) - 0.128 (M)
Distribution: Southeast Asia
Habitats: Secondary and montane forests and scrub
Diet: Insectivorous
Activity patterns: Nocturnal
Locomotion: Vertical clinging and leaping
Notables: Very large eyes
eSkeletons Specimen: Tarsius bancanus
Citations: Fleagle 1999
Species: M. murinus, M. myoxinus, and M. rufus
Dental Formula: 2.1.3.3./2.1.3.3.
Body Mass: 0.042 (F) - 0.043
Distribution: Madagascar
Habitats: Dry secondary forests (M. murinus and M. myoxinus); humid secondary forests (M. rufus)
Diet: Foraging faunivorous, some fruits, leaves and nectars
Activity patterns: Nocturnal
Locomotion: Arboreal quadrupedalism
Social Systems: Solitary
Notables: Smallest living primates
eSkeletons Specimen: M. rufus
Citations: Fleagle 1999
Dental Formula: 2.1.3.3./2.1.3.3.
Body Mass: 3.52 (F) - 3.63 (M)
Distribution: East coast of Madagascar
Habitats: Forest
Diet: Frugivorous
Locomotion: Arboreal quadrupedalism
Social Systems: Seasonal changes in group cohesion
Notables: The largest lemurid
eSkeletons Specimen: Varecia variegata
Citations: Fleagle 1999, and Harcourt et al 1995
Species: G. senegalensis, G. moholi, G. gallarum
Dental Formula: 2.1.3.3./2.1.3.3.
Body Mass: 0.250 (F) - 0.315 (M)
Distribution: Senegal to east Africa (G.senegalensis), southern Africa (G. moholi), eastern Africa (G.gallarum)
Habitats: forest, savannah, open woodlands, isolated thickets
Diet: Insects, some gums
Activity patterns: Nocturnal
Locomotion: Leaping
eSkeletons Specimen: Galago senegalensis
Citations: Fleagle 1999
Species: N. coucang, N. pygmaeus
Dental Formula: 2.1.3.3./2.1.3.3.
Body Mass: 0.626(F) - 0.679(M)
Distribution: Southeast Asia
Habitats: Main canopy
Diet: Frugivorous
Activity patterns: Nocturnal
Locomotion: Slow quadrupedalism and climbing
Notables: Tail is greatly reduced
eSkeletons Specimen: Nycticebus coucang
Citations: Fleagle 1999
Adapted from Fleagle 1999
