Tarsiers (week 11)

partially closed orbits in tarsiers

-descended from omomyids, which had open orbits 1. tarsier closure is caused primarily by flanges of the sphenoid and maxilla bones 2. anthropoid closure is caused by a large flange of the zygomatic bone 3. tarsier partial closure is therefore convergent with that of anthropoids 4. tarsier's postorbital plates probably provide support for the protruding eyeball

tarsiers and anthropoids

1. dry nose with whole upper lip 2. hemochorial placenta 3. lack of a tapetum lucidum 4. grooming claw on one or two toes 5. greatly enlarged tarsals

small to large eye

eastern, phillippine, western

strepsirhines

1. relatively long rostrum 2. post orbital bar 3. temporal fossa 4. no plate

western tarsiers

island areas of sundaland

small to large ear

western, phillipine, eastern

know specifics of slide 29

slide 29

Tarsius bancanus and syrichta

no group living, but overlapping home ranges

fovea centralis

gives you sharp central vision. It's present in anthropoids, but not in prosimians. However, tarsiers appear to have a slight fovea. fovea: a local point in the retina densely packed with receptors

tarsiers vs. anthropoids

tarsiers: maxilla and sphenoid anthropoids: zygomatic

memorize slide 13

memorize slide 13

tarsier dental formula

2.1.3.3./1.1.3.3.

Necrolemur

-eocene omomyid -from europe

Rooneyia

another omomyid from N. America another large socket

philippine tarsiers

greater mindanao

orbits in tarisers

half way there, not entirely closed from behind

characteristics of the eastern tarsiers

1. furriest tail 2. mid-tarsal segment of the hind foot is well-furred

haplorhines

1. relatively short rostrum 2. plate separating orbits from temporal fossa

what do the molecules say?

1. mtDNA consistently links tarsiers with strepsirrhines 2. nuclear genes are inconsistent, some links with streps, others with anthropoids 3. other methods are inconsistent 4. the split is probably too ancient for molecules to resolve it now 5. recent molecular clock estimates set the 3-way divergence at around 60 mya

nocturnal eye from front to back

1. pupil 2. iris 3. lens 4. retina 5. tapetum primate is lab rat too

why have big eyes?

1. tarsiers are missing a tapetum lucidum 2. enlarging the eye allows more light to enter, for increased visibility 3. tarsiers also have a slight fovea, which strepsirrhines do not

conclusions in ultrasound study

1. under the darkest nocturnal conditions--when cloud cover occludes starlight--it is plausible that the exceptional hearing of tarsiers contributes to improved foraging efficiency through acoustic eavesdropping 2. for instance, tarsiers might attend to ultrasonic signals between prey species (e.g. katydids and moths) or broad-band cues signifying the presence and location of potential prey, such as rustling leaves

auditory and tarsiers

1. upper auditory limit of 91KHz, higher than all other primates 2. one distinct call that was entirely ultrasound

Tielhardina

Early Eocene Omomyid Asia, Europe, N. america very big eye socket

eastern tarsiers

sulawesi and nearby islands

tarsiers of South India

1. Tarsius syrichta 2. Tarsius bancanus 3. Tarsius dianae 4. Tarsius spectrum 5. Tarsius pumilus

features of a tarsier skull

1. enormous eye sockets 2. pretty jagged teeth 3. pointed incisors although not a toothcomb exactly, and not spatulate incisors either 4. despite it's large size, it's eyes are frontated and convergent

features of a tarsier

1. eyeballs 2. tarsals 3. imi: long legs, low imi, jump

why is a tarsier unique?

1. fused tibia and fibula 2. longest foot bones of any primate 3. enlarged, pointed anterior teeth (incisors)--not toothcomb or spatulate incisors 4. unique jaw joint that allows gutter-like fore and aft movement 5. resembling the Eocene omomyids in all the above features 6. largest babies relative to body size of any primate 7. diets consisting almost entirely of animal prey, sharing this glory with Loris

T. spectrum

1. group size is variable 2. groups generally have 2 adult females, indicates multiple breeding females per groups 3. facultative polygyny

characteristics of western tarsiers

1. intermediate furriness 2. well-furred mid-tarsal segment of the hind foot

characteristics of philippine tarsiers

1. least furry 2. mid-tarsal segment of the hind foot is nearly naked

tarsier reproduction

1. litter size: strictly one offspring 2. they have a bicorneate uterus capable of producing 2 offspring but they do not 3. all tarsiers have 2-3 pairs of mammary glands 4. they might have been producing more offspring in the past than they do today 5. they tend to be seasonal breeders, specially in the wild but not so much in captivity

tarsier reproduction part 2

we used to think that tarsiers were relatively inattentive parents, parking their infants during the night and going off to to forage on their own but new research has shown that they have as many as 11 parking spots during the night, mothers are of an average of only 4 m from their infants and they typically remain in the same tree as their infant when they forage