Comparative Primate Blog

Chimpanzees
Chimpanzees spend an equal amount of time on land and in trees, but they spend most of their eating and sleeping time in the forest canopy. They inhabit a variety of wooded habitats across equatorial Africa such as evergreen forests, woodlands, grasslands, savannas, tropical rain forests, and swamp forests.

Chimpanzee dentition is 2:1:2:3. It includes two incisors, one enlarged canine, two premolars, and three molars. Their muzzle is shorter and flatter than most other primates.

Chimpanzees’ teeth are used for a variety of reasons. They use them to eat food like fruits, leaves, palm-nuts, seeds, and meat. They use their canine teeth to grab their prey and flail it to death on the ground, or against a tree limb. They also use their teeth to extract ants and termites.

Spider Monkeys

Spider monkeys live in areas that have large tracts of moist evergreen forests, and undisturbed rainforests. They are particularly found in the tropical forests of Central and South America, from the southern part of Mexico to Brazil. They live in bands of up to 35 other spider monkeys who forage together during the day. They are also diurnal, and sleep during the night in trees that have been carefully selected.

Their dentition is 2:1:3:3. They have big incisors and small molars, with three upper premolars that have one to two cusps. A diastema separates the upper canines from the upper incisors. There are also three bottom premolars that have 2-3 cusps.

Their four large incisors and small molars exemplify the spider monkeys’ frugivorous diet which consists of mostly fruits and nuts. Sometimes they will also eat leaves and flowers, and if food is low, they will eat insects, bark, and honey. They eat fruits from large forest trees, which they can swallow whole. Spider monkeys are hunted by humans, and are also threatened by logging and land clearing. Therefore, their teeth are adapted to eating many different types of food, and are adapted to easily get more difficult food such as bark, honey, and insects. Their molars help them to chew harder food like nuts.

Baboons
Baboons are terrestrial, and live in locations where there are water sources and safe places to sleep, such as tall trees or cliff faces. They are found in savannas, woodlands, open savannah, open woodland, and hills across Africa.

Baboons’ dentition is 2:1:2:3 and consists of sexually dimorphic canines. They have long lower premolars, which sharpen their large canines. They also have geladas which have complex enamel folding in their molars.

Baboons use their sharp molars to hunt for food like insects, fish, shellfish, birds, and small antelpoes. They forage throughout the day and night and their teeth can be very useful for eating and killing a wide variety of prey, even including sheep or goats.

Gibbons
Gibbons are arboreal and spend less than 1% of their time on the ground, to keep safe from their ground-dwelling predators. They live in deciduous, evergreen, and tropical rain forests in southeast Asia. They can be found in the canopy of trees, as well as the highest branches of trees, and dwell in areas that are seasonally wet and consist of a lot of berries, fruits, and flowers.

Gibbons’ dentition is 2:1:2:3 and consists of one canine, two incisors, three molars, and two premolars. Their teeth are small, except for the canine, which is very long and sharp in both males and females.

Gibbons diet consists of fruit, leaves, insects, figs, and bird eggs, which explains why the majority of their teeth are small.

Lemurs
Lemurs live in the forests of Madagasgar, and cope with very seasonal environments, and can live in many different ecological niches due to Madagasgar’s harsh and seasonal climate.

Lemur detention consists of several tooth morphologies and is comes from a primate of the 2.1.3.3. dentition. In their toothcomb, their bottom incisors and canines face forward and are thinly spaced, which is used for grooming, feeding, or prying out seeds, cutting bark. Their toothcomb consists of four incisors and two canines, except indriids, monkey lemurs and sloth lemurs have four-toothcomb due to the loss of a canine or incisor. Lemurs are dentally precocious when they are born, and have full permanent dentition at weaning. The largest species of lemurs also have rapid dental development. They also have thin tooth enamel.

Because of their thin tooth enamel, lemurs often cause extra wear or breakage of their front teeth due to use for grooming, feeding and fighting. Lemurs use their lower teeth as combs to rake or scrape through fur. They use their teeth to discourage interaction with others, or even use them to slash others during fights. They rely on their teeth to tear through tough-skinned fruit. Their toothcomb is used along with their two grooming claws on their hind feet to comb through hair. They also eat fruit, leaves, flowers, insects, tree gum and sap.

After researching these five primates, I have realized that the environment directly influences their physical and behavioral traits. There is a reason for their canines and incisors, and a reason for toothcombs. Chimpanzees spend most of their time in trees, so therefore, most of their diet consists of things like fruits, nuts and leaves, which is why they have two incisors and one canine. Spider monkeys are foragers who also live in areas where there is logging and a lot of human disturbance, so they can eat leaves and flowers from the ground as well as bark and honey if they are in trees. Therefore, they don't need a lot of large teeth for those foods, but they do have big incisors for getting more difficult meals. Baboons spend a lot of time on the ground as well as in the trees, so they have large mouths and sharp incisors to catch prey like fish, birds, and insects. Gibbons spend hardly any time on the ground,and spend time at the highest of the tree tops so they have a smaller mouth with smaller incisors for eating insects, leaves, and figs. Lastly, lemurs can fit many different ecological niches and deal with harsh, seasonal climates so they eat a variety of small food. They also have to pay special attention to their fur which needs to be cleaned often, which results in their toothcomb. Therefore, the environment has a huge influence on physical and behavioral traits, and it's interesting to see how primates have adapted over time to work with these environments.