Monkeys :: essays research papers

There be at least 145 living species of the suborder Anthropoidea . Over 90% of them atomic number 18 monkeys. The remaining species argon apes and humans. The anthropoids (members of the suborder Anthropoidea) befuddle been the most successful primates in populating the earth. They argon generally larger, more intelligent, and swallow more highly develop eyes than the prosimians.There are two distinct infraorders of Anthropoidea that have been evolving independent of each other for at least 30,000,000 years. They are the superfamily Platyrrhini (New World monkeys) and the Catarrhini ( ageing World monkeys, apes, and humans). These two diverse groups of species can be expansive from each other most easily based on the discrepancy of their noses and by the number of specific types of teeth.The platyrrhine nose (on the left below) is relatively flat with somewhat sideways projecting nostrils separated by a wide septum. In contrast, the catarrhine nose (on the right below) has more downwardly projecting nostrils separated by a small septum.Nose similarity of an emperor tamarin (left)and a Celebes black macaque (right) All primates have essentially the same kinds of specialized mammalian teeth adapted to ingest a wide variety of foods. Beginning at the front, each quadrant of the mouth has 2 incisors, 1 canine, and varying numbers of premolars and molars. The incisors are apply like scissors for nipping off pieces of food. The pointed canines are for piercing and tearing. The premolars and molars, with their cusps, are used to grind and smash food. In platyrrhine species, there are 3 premolars and 2 or 3 molars. This results in a alveolar consonant consonant formula of 2.1.3.2 or 2.1.3.3. In contrast, all of the catarrhines have 2 premolars and 3 molars, making a dental consonant formula of 2.1.2.3. The chimpanzee shown below is an sure-enough(a) World anthropoid species and, therefore, has a catarrhine dental formula.Catarrhine 2.1.2.3 dental formu la (common chimpanzee) All anile 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, only if 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.Patas monkeys in an Africangrassland environment In addition to these differences, New World monkeys are almost exclusively arboreal and most of them are smaller than Old World monkey species. Some Old World monkeys and apes are semi-terrestrial. If you capture a group of monkeys casually walking around in a grassland environment (like those shown on the right), you can be sure that they are from the Old World.