ANT333 Lecture 3 - Review of Living Primates & Systematics: Lorisoids, Tarsiers,
& New World Monkeys
Smaller, mainland radiation of strepsirhines.
Galagos (family Galagidae) restricted to Africa, very small
Lorises (family Lorisidae) found in Africa & Asia.
Lorisoids have “classic” Strepsirhine features: dental tooth comb, grooming claw on 2nd digit, &
Differ in cranial features to lemurs.
Lorisoids vs. Lemuroids
o Pharyngeal artery provides main blood supply to brain
o Tympanic ring fused to lateral wall
o Stapedial branch provides main blood supply to brain
o Tympanic ring suspended with bulla
1. Family Galagidae
Very diverse group; little agreement on systematics.
Generally, 4 genera: Otolemur, alago, Euoticus, & Galagoides.
Body weights: range from 60 g (Galagoides demidoff) to 1100 g (O. crassicaudatus).
Diet composed of insects, fruit, & gum (varies among species).
All galagos are nocturnal.
Nyctocebus pygmaeus – only mammal with neurotoxic chemicals
2. Family Lorisidae
Also diverse group, with up to five genera.
Body weights range from ~ 270 g (Loris tartagratus) to 1110 g (Nycticebus coucang).
Generally, diet is either largely frugivorous or insectivorous.
All taxa tend to be slow and stealthy in their movements.
All taxa are nocturnal.
Differences between Strepsirhines & Haplorhines
Feature Strepsirhines Haplorhines
Frontal bone Unfused Fused
Mandibular Symphysis Unfused Fused
Post-orbital Region Lack of closure Closure
Tympanic ring Lying free within bulla Fused to lateral wall of auditory bulla
Grooming claw Present Absent
Nose Short rostrum Long rostrum
Orbits Plate separating orbits Post-orbital bar (can see through eye)
1 Tarsiiformes: Tarsius
Multiple species in Tarsius.
Body size in all species between 100-130 g.
All living tarsiers nocturnal, vertical clinging and leaping, faunivorous animals.
Most authorities feel Tarsius & higher primates share enough distinctive cranial, dental, and
reproductive features to justify grouping them in the haplorhines.
Hunt by smell/sound
Feature Platyrrhini Catarrhini
Nostrils Broad Narrow