This lecture will address basic primate classification. Primates are classified based on their features- primates that share certain features are classified into the same group. There are lots of different ways of classifying animals- using an evolutionary taxonomy (like Linneaus’ family tree) or using cladistics. We are going to stick with the evolutionary taxonomy. There is a chart in your book- on Page 168-169 of your book- I would suggest that you have that open as you read this week’s material. It will make sense, I promise!
FYI- some books have an errors in the charts on pages 168-169. Make sure that your chart lists Cercopithecoidea and Hominoidea in the Superfamily category, and not the Infraorder category.
Terms: arboreal Post orbital bar or plate Anthropoids Cercopithecoid
Prehensile platyrrhine quadrupedal
Pentadactyly catarrhine ischial callosities
Prosimians 2-1-3-3 bilophodont
Rhinarium 2-1-2-3 sexual dimorphism
Hominoidea brachiation Y-5
Hylobatidae Pongidae Pongo
Gorilla pan knucklewalking
Pan troglodytes Pan paniscus
What is a primate?
Primates are very generalized group that cannot be easily identified by 1 or two characteristics. In fact, primates have suite of characteristics. Keep in mind that primates are adapted to an arboreal (tree) lifestyle. Think about how these characteristics would help an animal living in the tree.
In order to be considered part of the Order primates, an animal must have several of the following characteristics:
1. At least 1 nail on a digit of the hand or foot
2. post orbital bar or plate (bony ring protecting eye socket)
3. forward facing eyes with stereoscopic vision (3D)
4. upright posture- spinal column comes in under skull, rather than at the back
5. prehensile hands and feet (grasping)
6. pentadactyly (5 digits on hands and feet)
7. opposable toe and/or thumb
8. enlargement of cerebral hemisphere of brain
9. one pair of mammary glands (implies single