Primates Dentition Patterns

Krystal Morrice

Anthropology Week 4

Blog Post

25 February 2013

:  Lemurs:

a.        Lemur is a “forest creature”. They are mostly found on the Madagascar islands, which are located off the coast of Africa. That is why they are called a forest creature, being that they mostly live in a tropical forest. However, sometimes they are known to build habitat in a more dry forest. Either way, Lemurs are known to be herbivores and are built with the strength to climb tree and jump from one place to another.

Madagascar lies in the Indian Ocean off the southeast coast of Africa opposite Mozambique. The world's fourth-largest island, it is twice the size of Arizona. The country's low-lying coastal area gives way to a central plateau. The once densely wooded interior has largely been cut down (http://www.infoplease.com/ipa/A0107743.html).

Researchers have reported that almost all species of Lemurs are close to becoming extinct. The arrival of homo-sapiens has endangered Lemurs and their habitat.

b.      The lemur dentition is heterodont, which means having multiple tooth morphologies. This derives from an ancestral primate permanent dentition of . There are also noticeable differences in dental morphology and tooth topography between lemurs. Indri, a type of Lemur, has teeth that are perfectly adapted for shearing leaves and crushing seeds. In the toothcomb of most lemurs, the bottom incisors and canine teeth are procumbent, which face forward rather than up and are finely spaced; provide a tool for grooming or feeding. Lemurs are also dentally precocious at birth, and have their full permanent dentition at weaning. For instance, indri use their toothcomb not only for grooming, but also to pry out the large seeds from Beilschmiedia fruits, while fork-marked lemurs use their relatively long toothcomb to cut through tree bark to induce the flow of tree sap (http://en.wikipedia.org/wiki/Lemur#Dentition). As you can see these animals have different characteristics to help them in the environment they live, which brings me to the next question; how the primate’s trait expression has been influenced by their environment.

c.       Like I discussed in bullet point B, different species of Lemurs have different types of dentition patterns; each useful for a different skill or task. The tooth comb in each species of Lemur differs and is useful in the environment that they live in. I.E) Indri Lemurs tooth comb allows them to pry out large seeds from the fruit that they have to eat, while fork-marked Lemurs’ toothcomb has adapted to be sharper and longer than most in order to cut through tree bark to get to sap.

Spider Monkey:

a.       Similar to some Lemurs, Spider Monkeys also live in tropical climates, except instead of building its habitat on the Madagascar Islands, they specifically are found in the evergreen forests of Central and South America, as well as, being found as far north as Mexico. Spider Monkeys are arboreal, meaning they are inhabits in trees. They thrive in the upper canopy, which allows these primates to hunt with ease and without the competition of other types of primates (http://www.macalester.edu/~montgomery/spidermonkey.html).

b.      Spider Monkeys usually have a small face with a blunt snout. Just like the dentition pattern of a lemur, some spider monkeys have the dentition pattern of: 2 incisors, 1 canine, 3 premolars, and 3 premolars. In the upper dental arcade of a spider monkey the molars set farther apart than the canines. The lower dental arcade is more U-shaped, with the cheek teeth rows set closer together and running more parallel to one another. The Incisor teeth of the spider money are usually the more notable dentition feature. Upper and lower incisors are relatively wide and high-crowned. Researchers also show that male and female spider monkeys have different dentition patterns. (http://www.academia.edu/392092/Morphology_and_evolution_of_the_Spider_Monkey_Genus._Ateles).

c.       Spider Monkeys live in tropical forests and they are fruit eaters. They use their incisors to pick fruit off the trees. “Dental micro-wear studies of Ateles show a scratch-dominated pattern related to the consumption of seeds and pulp of mature fleshy fruits (Kay,1987)  (http://www.academia.edu/392092/Morphology_and_evolution_of_the_Spider_Monkey_Genus._Ateles).

Baboon:

a.       Baboons are known to be one of the most adaptable and flexible primates on earth. They are able to adapt to most any environment and occupy an array of different habitats across Africa and the Arabian Peninsula. Baboons are omnivorous, which means they will eat almost anything and will change their diets as the environment around them changes. Even though baboons move and adapt to any environment that they are in, they are said to usually sleep in trees, on cliffs, in caves, or under rocky overhangs.

b.      Old world moneys, such as the baboon, share this 2.1.2.3 dental formula. All baboons have a snout-like face, the same dentition with long, sharp canine teeth, and powerful jaws.

c.       Since baboons have to adapt to their environments, food sources and all, they eat both plant and animal materials. Which is one of the reasons that their teeth are so sharp, long, and strong. Having to break through harder tougher food items has adapted their teeth to be able to function in most any environment.

Gibbon:

a.       The gibbon is a small sized ape, which is found mostly in the dense jungles and tropical rainforests across south-east Asia. The Gibbon monkey is classified as an arboreal, meaning that they spend most of their lives in trees.

b.      The dental formula in hominoids is the same as in all other catarrhine primates: 2.1.2.3 / 2.1.2.3. The generalized formula for Old World monkeys and apes. The dental arcade is U-shaped, and the mandible is thin and light. The incisors are broad and flat, while the molars have low, rounded cusps with thick enamel. The most noticeable characteristic of the dentition of Hylobates, Gibbon, is the presence of large, dagger-like canines in both the upper and lower jaw. These canines are not sexually dimorphic. (http://www.gibbons.de/main/introduction/chapter_english01.html).

c.       Gibbons are omnivorous animals, similar to the baboon, meaning that they eat a mixture of both plant and animal matter. The main food of the gibbon is ripe fruit which grow around them in the trees, but they also eat insects, birds, small spiders, eggs, and reptiles. Just like with the previous primates, what they eat reflects their dentition patters. Like stated in letter B bullet point, Gibbons have large dagger like canines. These canines are useful to the canines for eating the fruit, as well as the other food items they eat. Were they always like this? Or did they adapt to the environment that they lived in? It is a definite possibility; however, most research states that the generalized formulas for all old world monkeys are the same. This is probably because they eat similar food, but it also could just be a genetic dentition patter in these types of primates.

Chimpanzee:

a.       Chimpanzees can be found Central and Western Africa. They range from Senegal to Tanzania and are usually found along the river Zaire. They like to live in humid and deciduous rainforests. They also like swamplands, grasslands and woodlands (http://www.iearn.org.au/greatapes/chimps.htm).

b.      I found some interesting facts about Chimpanzee dental patterns and the evolution of their dentition patterns.

A revised dental growth chronology for chimpanzees is similar to estimated timing of Homo erectus and therefore has implications for interpreting life history in hominins. The sequence and timing of dental emergence correlate with life history events in catarrhine primates, which include Old World monkeys, apes, and modern humans (http://www.pnas.org/content/101/29/10541.full).

The first permanent molar is informative for comparing chimpanzee life history because its full eruption relates with the end of infancy and completion of the brain growth in species studied so far. The molar eruption also provides a measure for comparing chimpanzees, modern humans, and fossil hominins.

c. Like I stated above, chimpanzee’s dentition patterns have changed over the years through evolution. I believe that environment has a huge influence in all primates changes throughout the years, whether it is dentition patterns, diets, or even the way they walk.

Works Cited

"              Baboons - Physical Characteristics, Social Behavior, Baboon Friendships, Food And Foraging Habits, Communication, Baboon Models - Living, Africa, Monkeys, and Ground                 - JRank Articles                    ."            Science Encyclopedia                           - JRank Articles                    . N.p., n.d. Web. 26 Feb. 2013. <http://science.jrank.org/pages/706/Baboons.html>.

"            Lemurs." Globio | Where Kids Discover the World | Portland, OR. N.p., n.d. Web. 26 Feb. 2013. <http://www.globio.org/glossopedia/article.aspx?art_id=49>.

"Baboon Ecology | Imfene." Imfene Education & Conservation | Imfene. N.p., n.d. Web. 26 Feb. 2013. <http://www.imfene.org/baboon-biology/baboon-ecology>.

"Lemur - Wikipedia, the free encyclopedia." Wikipedia, the free encyclopedia. N.p., n.d. Web. 26 Feb. 2013. <http://en.wikipedia.org/wiki/Lemur#Dentition>.

"Madagascar:    Maps, History, Geography, Government, Culture, Facts, Guide & Travel/Holidays/Cities — Infoplease.com." Infoplease: Encyclopedia, Almanac, Atlas, Biographies, Dictionary, Thesaurus. Free online reference, research & homework help. — Infoplease.com. N.p., n.d. Web. 26 Feb. 2013. <http://www.infoplease.com/ipa/A0107743.html>.

"Morphology and evolution of the Spider Monkey, Genus. Ateles | Siobhan Cooke - Academia.edu." Academia.edu - Share research. N.p., n.d. Web. 26 Feb. 2013. <http://www.academia.edu/392092/Morphology_and_evolution_of_the_Spider_Monkey_Genus._Ateles>.

"Spider Monkey." Macalester College: Private Liberal Arts College. N.p., n.d. Web. 26 Feb. 2013. <http://www.macalester.edu/~montgomery/spidermonkey.html>.