Understanding Primate Anatomy and Dental Diversity

Wichita State University Name: _______________________ ANTH 106 Spring 2020 Tuesday/Thursday Instructor: Buchanan-Burke LAB # 9 – Primates: Anatomy and Diversity OBJECTIVES:  Reinforce your knowledge of teeth and cranial bones of nonhuman specimens.  Learn about primate dental morphology and its relationship to diet. KEY TERMS: strepsirrhine, haplorrhine, platyrrhine, catarrhine, cercopithecoid, hominoid, hominin, enamel, cementum, dentine, crown, neck, root, occlusal, cusps, crests SECTION 1: Modern Primates The primate clade is comprised of a number of major groups that differ from one another genetically and in physical features, including a number of osteological and dental characteristics. In this lab, we examine some of these features in the skulls of a variety of primate taxa. The first step in understanding the differences between humans and other primates is to understand how modern primates relate to each other. The following is a cladogram of primate relationships.

If you are not familiar with the various types of living primates, refer to your textbook. If you are confused about any of the terms about teeth, skip ahead to Section 2 in this lab to read over basic information about teeth in primates. Strepsirrhines: Primates that are found on the island of Madagascar (Lemuroidea) or in Africa and eastern Asia (Lorisoidea) Haplorrhines: The more derived primates, including: Tarsiers: found in Southeast Asia and the Philippines Platyrrhines: monkeys from Central and South America (i.e. New World Monkeys) Catarrhines: monkeys ( cercopithecoids ) and apes/humans ( hominoids ) from Africa & Asia The major groups of primates can be easily distinguished from each other on the basis of features of their skulls and teeth. 1. Non-Primates and Primates : All primates have a bony rim that completely encircles their orbits. All primates have forward-facing orbits. Primates have a relatively larger brain than non-primates. 2. Strepsirrhines and Haplorrhines : Strepsirrhines tend to have longer snouts reflecting their greater reliance on smell. Strepsirrhines have tooth comb incisors. Strepsirrhines have an ectotympanic ring while haplorrhines have an endotympanic ring Strepsirrhines are often nocturnal; haplorrhines are usually diurnal. Haplorrhines have a fused mandible. Haplorrhines have an eye socket enclosed in bone. This is known as a post-orbital plate. 3. Tarsiers, Platyrrhines, and Catarrhines : Catarrhines have downward-pointing nostrils; platyrrhines have outward-pointing nostrils Platyrrhines have prehensile tails; in catarrhines, tails aren’t prehensile or may be absent. Catarrhines have two premolars and a 2-1-2-3 dental formula. Platyrrhines have three premolars and a 2-1-3-3- dental formula. Tarsiers have a 2.1.3.3./1.1.3.3. dental formula. Tarsiers have very large eyes relative to cranial size. 4. Cercopithecoids from Hominoids : Hominoids have larger brains than cercopithecoids. Hominoids have five cusps on their lower molars and a Y-5 fissure pattern. 5. Hominoids from Hominins: Hominoids have lower third premolars that are single-cusped. Hominoids have lower faces that project more than hominins Hominoids have larger canines that are “honing” Hominoids have relatively smaller brains than hominins. Hominoids have a foramen magnum placed far under the brain case

SECTION 2: Dental Morphology in Primates Teeth are composed of several tissues – enamel (the hard chewing surface), dentine (the softer interior), and cementum (which “cements” the teeth to the jaw). They can be divided into several parts – the crown (which protrudes above the gum), the neck (or cervical margin), and the root. The morphology of the occlusal (or chewing) surface of teeth is composed of cusps and crests. Because enamel and dentine are the two hardest organic materials in the mammalian body, they are the most easily preserved in the fossil record. Thus, a great amount of the information we have on fossil primates is based on their dental morphologies. Adult dentition per quadrant follows a 2.1.2.3 pattern

Your preview ends here

Eager to read complete document? Join bartleby learn and gain access to the full version

Access to all documents
Unlimited textbook solutions
24/7 expert homework help

IN CLASS EXERCISE (25 pts) Navigate to the following link. http://www.eskeletons.org/compant Choose a minimum of five of the eight primates listed below.  Mouse Lemur  Tarsier  Squirrel Monkey  Marmoset  Baboon  Orangutan  Gorilla  Chimp View the comparative anatomy skeletons for each of your selected primates and view their skeletal traits. Describe the skeletal anatomy for each of the primate, and explain which group they belong to (e.g. strepsirrhine or haplorrhine). Use your descriptions of skeletal traits to justify why the selected primates belong to each group. (4.5 pts) Primate #1_____Gorilla_________ Description of traits: They have a postorbital plate and a dry/ naked nose Group: Haplorrhine (4.5 pts) Primate #2_______Orangutan_______ Description of traits: They have a dry naked nose and flattened nails Group: Haplorrhine

(4.5 pts) Primate #3____Chimp__________ Description of traits: They also have a dry and naked nose along with a flattened nails. Group: Haplorrhine (4.5 pts) Primate #4______Squirl Monkey ________ Description of traits: They have a reduced olfactory bulb and flattened nails. Group: haplorrhine (4.5 pts) Primate #5______Baboon________ Description of traits: They also have a reduced olfactory bulb and dry naked nose. Group: (4.5 pts) Primate #6______________ Description of traits: Group:

TAKE HOME ASSIGNMENT: Watch the following video on orangutans, and answer the following questions. https://www.youtube.com/watch?v=0fts6x_EE_E 1. (4.5 pts) Briefly describe orangutan social structure. Mostly solitary and territorial animals 2. (4.5 pts) Where orangutans found? Two big islands Sumatra and Borneo in southeast Asia 3. (4.5 pts) Describe two adaptations that represent orangutans’ ability to learn and share culture. They can make pillows when they go to sleep and make umbrellas to keep them dry while it rains. 4. (4.5 pts) What is the one of the greatest threats to orangutans today? Deforestation and forest fires

Your preview ends here

Eager to read complete document? Join bartleby learn and gain access to the full version

Access to all documents
Unlimited textbook solutions
24/7 expert homework help

106 - LAB 9 Online (1)

Related Documents