*Palæos:*		Unit 480: Archonta
*The* *Vertebrates*		500: Haplorhini

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Archonta: Haplorhini

Cladogram

EUTHERIA
|--INSECTIVORA 
`--+--+--ANAGALIDA    
   |  `--Archonta
   |     |--+--Scandentia
   |     |  `--Primatomorpha
   |     |     |--Plesiadapiformes
   |     |     `--Primates
   |     |        |--Strepsirhini
   |     |        `--Haplorhini 
   |     |           |--Tarsiiformes
   |     |           `--Anthropoidea
   |     |              |--Platyrrhini
   |     |              `--Hominoidea
   |     `--CHIROPTERA
   `--+--FERAE
      `--UNGULATOMORPHA

480.000 Overview
480.100 Archonta
480.400 Primates
480.500 Haplorhini
Cladogram
References

Descriptions

Haplorhini: men & monkeys. Defined as tarsiers + Texans

Range: from the Early Eocene.

Phylogeny: Primates : Strepsirhini + * : Tarsiiformes + Anthropoidea.

Characters: short rostrum; tooth comb absent; spatulate incisors; fused mandibular symphysis; upper lip undivided; vibrissae absent; loss of rhinarium; nostrils not separated; $ tapetum lucidum absent [R00]; "fused metopic suture" (??); postorbital septum separates orbits from temporal fossa; $ fovea centralis present {R00]; $ middle ear with anterior accessory cavity if the petrous temporal bone (enhances hearing at low frequencies) [R00]; internal carotid artery; reduced olfactory brain centers; hemochorial placenta present; diurnal.

Links: primate1.html; Haplorhini; primates.jpg; ketal 1997.pdf; Order Primates; Order Primates; Time Based Phylogenetic Classification; human2 (German); r2000.pdf; prosimian BC200 locus JMB.pdf.

References: Ross (2000) [R00]. ATW011028.

Tarsiiformes: Tarsiers > Texans. Necrolemur, Tarsius.

Range: from the Early Eocene of Asia, Europe & North America. Molecular phylogenies place the divergence time in the Paleocene, which seems reasonable. Currently limited to Indonesia and surrounding islands..

Phylogeny: Haplorhini : Anthropoidea + *.

Characters: quite small; "dry nose" rhinarium covered with dry, hairy skin as in anthropoids; rostrum short; complete, hairy upper lip; tapetum lucidum absent; orbits anterior & closely spaced; eye sockets almost completely enclosed with bone; eyes are immobile in orbit; retinal fovea present; ears large; tubular ectotympanic; auditory bulla present and large; stapedial artery absent; mandibular symphysis unfused; dental formula (living genus) 2/1, 1/1, 3/3, 3/3; I1 large; lower incisors small; canines large; grooming tooth absent; head can rotate 180°; humerus with entepicondylar foramen; grooming claw present, but on pes 3 (not 2 as in Strepsirhini); no opposable digits; tibia & fibula fused over distal 1/3 (leaping adaptation); tarsals elongate (navicular & calcaneum); hemochorial placentation; placenta is discoidal & deciduate; nocturnal; feeds on insects & small lizards & birds (only living fully carnivorous primate); groups usually consist of mated pairs and their young; territories scent-marked & announced by vocal duets by both male and female; gestation 180 days with single offspring; mother transports infant for first few weeks by holding it in her mouth, parking it on a nearby branch while she forages.

Notes: [1] most of these characters are for the living genus Tarsius and may not apply to more basal forms. [2] Interestingly, no tarsiiforms have ever been found in Africa.

Image: (right) Tarsius syrichta; (left) skeleton of Tarsius, both from Infraorder Lemuriformes Suborder Strepsirhini Infraorder ... .

Links: Infraorder Tarsiiformes; Infraorder Lemuriformes Suborder Strepsirhini Infraorder ... (Best on the Web); Tarsiiformes; 2001-1; WORKING GROUP PRIMATE GENETICS Head of Working Group- Dr. Hans ... (one of the few reasonable molecular studies); 7. Fossil primates; Primates as an Adaptive Array; Lecture 19 - Tarsif. & Platyrr.; Fossil Primates 1 (new site? Very nice lecture outline from the Univ. of Leeds); 2001-1 (Beard abstract). ATW030113.

Anthropoidea: Texans > tarsiers [R00]. Some workers use a crown group definition, excluding the "Eosimiidae" and some other extinct groups. Afrotarsus, Bahinia, Eosimias.

Range: from the Middle Eocene, probably earlier.

Phylogeny: Haplorhini : Tarsiiformes + * : Platyrrhini + Hominoidea.

Characters: consistent trend to higher body weights [R00]; orbits highly convergent [R00]; orbits vertically oriented (related to having acute, overlapping fields covering range of action of forelimbs) [R00]; cornea with small diameter [R00]; eyes with high concentrations of cones & ganglion cells [R00] [2]; fovea present (synapomorphy of Haplorhini) [R00]; eyes with extreme magnification of foveal and parafoveal regions of the visual field in the visual cortex [R00]; $ retinal blood vessels absent from fovea [R00]; visual rods excluded from fovea (except Aotus) [R00]; unique eye shape emphasizing visual acuity over light-gathering capability [R00]; probably trichromatic vision (3 visual pigments differing in peak absorption wavelength) [R00]; changes in orbit orientation shifts origin of anterior temporal muscles anteriorly, & postorbital septum required to prevent distortion of eyeball [R00]; middle ear with anterior accessory cavity if the petrous temporal bone (enhances hearing at low frequencies) [R00]; further increase in brain size and particularly in neocortex [R00]; superficial masseters vertically oriented [R00]; mandibular symphysis fused [R00]; incisors vertically planted & spatulate [R00]; long power stroke in chewing cycle [R00]; well-developed Phase II wear facets on molars (see diagram at left) [R00]; primitively frugivorous & insectivorous, probably arboreal leapers [R00]; unusually long-lived.

Notes: [1] [R00] argues that anthropoid origins are related to shift from small nocturnal predator to large diurnal omnivore. Became diurnal first. [2] Cones are the visual receptors specialized for color and visual acuity. They operate best at high light levels. Cones transmit information to the visual cortex via ganglion cells. As one might expect, the lower the ratio of cones to ganglion cells, the higher the visual acuity. Anthropoids have an unusually low ratio. This measure actually understates the degree of visual specialization, because anthropoids have a strongly disproportionate number of ganglion P-cells which register color and shape, as compared to the ganglion M-cells, which register contrast and movement.

Links: Anthropoidea; subordo Anthropoidea; anthropoids; Affen; Faculty - Lecture #15; The BC200 RNA Gene and Its Neural Expression Are Conserved in ...; Primate Taxonomy; Lecture 2 Primate taxonomy; Primates - Introduction (French).

References: Ross (2000) [R00]. ATW021109.

Platyrrhini: "New World monkeys", including marmosets, tamarinds, titis, capuchins, squirrel monkeys, sakis, uacaris, and howling monkeys, etc. Spider monkeys > Spider Man.

Range: from the Oligocene. Originated in South America. Currently in South and Central America.

Phylogeny: Anthropoidea : Hominoidea + *.

Characters: nostrils large, separated by wide septum; orbital septum complete; zygomatic contacts parietal; ear without ectotympanic tube; dental formula 2/1, 1/1, 3/3, 2-3/2-3; tails prehensile; limited development of opposable digits; opposable digit 5, not 1 (??); quadrupedal; entirely arboreal; infants carried dorsally; scent marking common with scent glands.

Images: (right) from Infraorder Lemuriformes Suborder Strepsirhini Infraorder ... (left) Saimiri sciureus from primates.com - monkeys - uakari, showing the typical platyrrhine nose.

Links: platyrrhine monkeys; Platyrrhini; Platyrrhini; New World Monkeys- Platyrrhini; platyrrhini; newworldmonkeyinfopage; The Primates- Monkeys; Sub-Unit- Infraorder Platyrrhini; Parte 02 (Portuguese); human3> (German); Platyrrhine Molecular Datasets. ATW021110.

Hominoidea: apes. Gorilla, Homo, Hylobates, Pan, Pongo, Proconsul

Range: from the Late Oligocene or Early Miocene. cosmopolitan.

Phylogeny: Anthropoidea : Platyrrhini + *.

Characters: large body size; $ suture between maxilla & premaxilla meets nasal closer to the rostral end of the nasal than to the orbit [R99]; $ nasal quite flat between orbits, rather than forming parabolic ridge (reversed in Homo) [R99]; large frontal sinus; ectotympanic ring is drawn out to form an external bony auditory meatus (plesiomorphic); large brain size; $ width of palate at level of canines greater than width at P2 [R99]; dental formula 2/2, 1/1, 2/2, 3/3; incisors enlarged; "Y-5" molar pattern (see diagram); thorax broad; short thoracic region; body relatively shallow, front to back; ischial callosities absent (reversal); tail reduced or absent; arms usually longer than legs; scapulae dorsal rather than lateral; clavicles elongated; all forearm joints highly mobile; olecranon short; ulnar styloid process short; arms & fingers frequently long; $ head of astragalus (talus) narrow [R99]; bipedality & upright carriage common; young carried ventrally; almost all terrestrial (except orangutan) or brachiate in trees;

Note: as Rae notes, his results suggest that changes in the face came before changes in locomotion.

Image: (right) evolution of "Y-5" molar pattern from Family Cercopithecidae Superfamily Cercopithecoidea Family .... (right) thoracic regions of macaque & man, showing change in proportions and arrangement of forelimb girdle from Thomas Geissmann's Gibbon Research Lab.- Die Gibbons ( .... (lower right) the eminent hominoid, A. Alan Kazlev.

Links: Hominoidea; Superfamily- Hominoidea; Family Cercopithecidae Superfamily Cercopithecoidea Family ...; Hominoidea; Mosaic Evolution in the Origin of the Hominoidea; Ökologie fossiler und rezenter Hominoidea (German); Hominoidea; hominoid (with nice image of Proconsul); A New Origin for Hominoidea-; Thomas Geissmann's Gibbon Research Lab.- Die Gibbons ( ... (also in German. Best on the Web); Lecture 21 - Hominoidea; Link Voyager Archaeology Directory; Evolucao e Filogenia (Portuguese); Pun 2.3.htm; Altweltaffen (German); John A. Finarelli's Research Page; The Primates- Humans.