Week 3 - Dentition Pattern

Week 3: Dentition Patterns

Ring Tailed Lemur:

1.     ENVIRONMENT: Ring tailed lemurs generally live in dry environments or the highland areas of Madagascar. Dry environments include scrub that are plateau-like areas consisting mainly of shrubs and grasses and gallery forests that are evergreen forests which grow on the sides of river banks in otherwise dry areas such as deserts and grasslands. Lemurs live in the highlands of Madagascar in Montane forests, which are also called cloud forests, and look like something straight out of Jurassic park. They are in a nearly constant cover of clouds with moss being the most common plant.

2.     DENTITION PATTERN: Ring-tailed lemurs have a dentition pattern of

2.1.3.3

2.1.3.3  which means they have 2 incisors, 1 canine, 3 premolars, and 3 molars totaling 36 permanent teeth compared to their deciduous dentition of only 24 teeth [lacking last 3 molars]. The 4 incisors and 2 canines of the lower jaw stick out facing more horizontal than vertical creating a tooth comb used for grooming and eating.

3.     TRAIT ADAPTION: Lemurs eat fruits, leaves, small insects, nuts, and even tree sap. The tooth comb allows for a shearing effect that is beneficial when eating leaves of scraping sap off of trees. Also, the small incisors of the tooth comb would be beneficial for opening small nuts or insects allowing the animal to scrape out the edible parts. Molars in the back of the mouth are good for grinding what would probably make up most of the lemurs diet – leaves – whereas the canines that lemurs do possess would be good to get into an insects tough shell or get into any other small vertebrate it found.

4.     PICTURE:

Ring-tailed lemur: a.k.a “sun worshipers”

Toothcomb

White-Fronted Spider Monkey:

1.     ENVIRONMENT: Spider monkeys generally live in the tropical forests of central and south America from about Mexico to Brazil. They live in the upper layers of rainforests roaming about 82 to 95ft up.

2.     DENTITION PATTERN: Spider monkeys have a dental formula of

2.1.3.3

2.1.3.3  meaning they have 2 incisors, 1 canine, 3 premolars, and 3 molars. They have large incisors and small molars hinting to diet centered more towards fruits and small insects. They have cusps on all of their molars indicating the molars can be used for incising as well.

3.     TRAIT ADAPTION: Living in the forest, leaves would be the most abundant food around. Molars are essential to the grinding down of leaves and other plants. Incisors, and sharp molars that spider monkeys have, however, were adopted so as to take full advantage of the other beneficial foods in the forest such as small insects and fruits in which case they would need a set of teeth that could break through the skin of fruits and shells of insects.

4.     PICTURE:

MANDRILL BABOON:

1.     ENVIRONMENT: Baboons, particularly the Mandrill, likes to live in tropical rainforests, but drier climates such as gallery forests with savannas and open grassland.

2.     DENTITION PATTERN: Baboons, as is with all old-world monkeys, have the same dental pattern as humans with the formula being

2.1.2.3

2.1.2.3 meaning we have 2 incisors, 1 canine, 2 premolars, and 3 molars. This is in contrast with new world monkeys who have 3 premolars and 2 or 3 molars.

3.     TRAIT ADAPTION: Baboons have a dental formula signifying they have a varied diet like most primates. Grasslands and forests offer vegetation as a source of food, which could be easily ground down with premolars and molars, but baboons are omnivores. Incisors and canines would have been developed in order to take advantage of other food sources such as fruits, insects, and small animals.

4.     PICTURE:

GIBBON:

1.     ENVIRONMENT: Gibbons enjoy the thick rainforests of South East Asia which are either deciduous or evergreen. They rarely come down to the floor, living their lives entirely up in the trees.

2.     DENTITION PATTERN: Gibbons have a dental formula of

2.1.2.3

2.1.2.3 like old world monkeys and great apes. They have 2 incisors, 1 canine, 2 premolars, and 3 molars.

3.     TRAIT ADAPTION: Gibbon teeth are adapted for a varied diet. They enjoy fruit, leaves, insects, and small animals. Molars would have developed as a way to grind down vegetation whereas incisors and molars would have been developed to cut through meat and fruit allowing the gibbon to adopt a more beneficial omnivorous diet.

4.      

CHIMPANZEE:

1.     ENVIRONMENT: Chimpanzees enjoy the rainforests and wet savannas of Africa. They spend equal time on land and trees but mostly feed and sleep in trees.

2.     DENTITION PATTERN: Chimps, like humans, have a dental formula of

2.1.2.3

2.1.2.3. This indicates that they have a broad, omnivorous diet. They have broad incisors, with their upper molars being quadrate and bunodont and their lower molars being bunodont and possess a hypoconulid.

3.     Being omnivores, chimps need molars for grinding and incisors and canines in order to eat other things such as small animals. Having a diet that is mainly fruit, plant, and insect based, chimps needed to have adapted a set of teeth that would benefit them and allow them to take advantage of the beneficial food sources their home provided.

4.     PICTURE: 

ENVIRONMENTAL INFLUENCE ON EXPRESSION OF PHYSICAL AND BEHAVIORAL TRAITS:

PHYSICAL TRAITS:

All of the monkeys listed above have omnivorous diets, prompting evolution of equip them with a set of teeth allowing for multiple purposes. Their environments – mostly forests and svannas – where not only grass, but small animals, fruits, and insects allow for a more beneficial and full diet. Teeth such molars allow for the grinding of food, but they do not allow for the cutting or scraping of it. Traits such as tooth combs and canines allow the animals to more easily consume process the foods around them ultimately allowing for a more varied and healthy diet.