AN 102 – Lab 8
Lab 8: Fossil Apes and What is a Hominin? (33pts)
In this lab you will look begin looking at fossils and consider the ways a paleoanthropologist can distinguish a monkey from an ape, and what some extinct apes looked like.
1. Learn to identify primate characteristics in the fossil record
2. Learn about the earliest fossil primates and how they relate to extant primates
3. Understand how changes in climate and environment impacted the evolution of primates
4. Learn to distinguish the differences between habitual climbers and habitual bipeds
5. Learn the ways in which humans and human ancestors (hominins) differ from our closest living ape relatives and how we identify hominin fossils.
Station 1: Fossils and mammals
This is a (REAL) fossil of an Oligocene mammal from South Dakota. We will emphasize again, it is REAL so please be careful. If you pick it up, do not hold it away from its box. Hopefully, you can see that it is the anterior (front) part of a skull. Look at it, examine it - does it have any cranial features in common with primates? If so, what? [NOTE: it is not even remotely a primate] (1 pt)
Look at its teeth. Based on what you know about primate teeth, what kind of food do you think this animal ate? (1 pt)
Station 2: The earliest primates
Here you have a lemur, tamarin, adapid fossil, omomyid fossil and replica of “Ida” (the most complete adapid fossil ever discovered).
Adapids are early primates from the Eocene (34-59 mya). They, along with omomyoids, display primate traits including forward facing eyes, relatively larger brains, grasping hands and feet, and nails instead of claws. Please draw the adapid and omomyid skulls with generalized primate traits labeled. (4pts)
Though there is some debate about it within the scientific community, there is a general consensus that one of these (adapoids and omomyoids) is an ancestor to strepsirhines and the other to haplorhines. Which one do you think is the ancestral haplorhine? (1pt)
What feature that you observed on the skulls make you come to this conclusion? (1pt)
Now look at that slab with the skeleton on it. Which features allow us to identify “Ida” is a primate? (1pt)
Station 3: Early Haplorhines
There are skulls here from a platyrrhine (howler monkey), a cercopithecoid (a langur monkey), and a hominoid (siamang) for comparison.
a Examine the Oligocene (30-33 million years old) fossil casts of Aegyptopithecus and Sadaanius. Given that the hominoids and cercopithecoids did not diverge until about 25 million years ago according to genetics, what word best describes these skulls: hominoid (ape), cercopithecoid (Old World monkey), primitive catarrhine, or primitive platyrrhine? (1pt)
b Give one piece of evidence for your answer to 1a (hint: count the teeth) (1pt):
Station 4: The Miocene
Proconsul (19 mya; Kenya). This is generally known as a “dental apes”. Compare the dentition to the ape and to the monkey...