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23/11/2020

Do colobines have Bilophodont molars?

Do colobines have Bilophodont molars?

The bilophodont molar cusps of colobines are steeper and more pointed than those of cercopithecines.

What is the primate dentition?

A dentition with different kinds of teeth (heterodonty)—incisors, canines, and cheek teeth—is characteristic of all primates and indeed of mammals generally. The principal changes are a reduction in the number of teeth and an elaboration of the cusp pattern of the molars.

Do colobines have cheek pouches?

Two species of African colobine monkeys, the red colobus, Piliocolobus badius (above and below), and the black-and-white colobus, Colobus guereza (center). They have lower, more distinct cusps on their molar teeth than do colobines, and have cheek pouches for storing food.

What is the dental formula of Old World monkeys?

All Old World monkeys, apes, and humans share this 2.1.2.3 dental formula. This not only sets us apart from New World monkeys and prosimians, but it also reflects the evolutionary closeness of the Old World anthropoid species. By comparison, the general placental mammal dental formula is 3.1. 4.3.

Do Old World monkeys have Y-5 molars?

More specifically, the apes can be distinguished from Old World monkeys by the number of cusps on their molars: apes have five, the “Y-5” molar pattern, while Old World monkeys have only four in a “bilophodont” pattern.

Do primates have heterodont teeth?

Primates, like other mammals, have two sets of teeth: a primary dentition (comprising all “milk” or deciduous teeth plus the permanent molars) and a replacement (or secondary) dentition. The teeth are heterodont, their form varying in association with varying functions such as cutting, puncturing and grinding.

Why are the dental characteristics of the three primates different?

Distinguishing among primate dentition: The lower jaw of other primates generally has a sharper angle. Human premolars are called bicuspids because they have two cusps, or points. Also, the front teeth of apes are generally larger than the back teeth, while in humans, the back teeth are generally larger than the front.

What primates have cheek pouches?

An entire monkey subfamily, Cercopithecine, including guenons, baboons, and macaques, is defined by having cheek pouches, which extend down the sides of their neck.

Which of the following is characteristic of Colobines?

Colobines have a sacculated stomach that helps them digest leaves and cercopithecines have cheek pouches. Colobines have more space between the eyes, and their incisors are narrower than in the cercopithecines. These pouches open inside the cheek at the base of the teeth and extend down into the neck.

Where are the ridges on Colobinae teeth located?

The enamel is somewhat thickened on the inside margins of these teeth. These ridges are more pronounced on the central incisor than on the lateral tooth. The lower incisors of Old World monkeys are usually spatulate and subequal in size.

What kind of body does a colobine have?

Both males and females of this species have a short, turned-up nose, much like that of a female proboscis monkey. This species has very unusual body proportions for a colobine, with similar-sized forelimbs and hindlimbs and a short tail. They are sexually dimorphic.

Where does the digestive process take place in a colobine?

Colobines rely on foregut digestion (foregut-fermenting), meaning that a considerable part of digestive process happens in the stomach proper, as compared with hindgut digestion (hindgut-fermenting), where the crucial digestive process takes place behind the stomach within the parts of the hindgut.

Are there single male units in the Colobinae?

Single-male units exist among the Cercopithecus (guenons) and Colobinae (Asian langurs and African colobines). Langur males actively defend their units against all-male groups.