Printer-friendly worksheets for Lab 5 (Exercises 5.1-5.5)
By the end of this lab you will:
- Understand the types of biological materials from which fossils originate.
- Be able to determine the mode of preservation of fossilized remains.
- Recognize and be able to sketch fossil features such as symmetry and shell shapes that are key to fossil identification.
Paleontology is the sub-specialty within the geosciences that deals with the examination, classification and interpretation of fossils. Fossilized remains are the key to documenting the evolution of life on Earth. Paleontologists and other geoscientists use fossils in four main ways:
a. The field identification and correlation of fossils is used as an aid in geologic mapping.
b. The study of a fossil organism’s taxonomic classification helps us to understand the evolution of life through time. In taxonomy, an organism’s physical characteristics are used to place them within a classification scheme using a nested hierarchy from kingdom (the largest grouping), through phylum, class, order, family, genus, to species (the most specific grouping).
c. The presence or absence of fossils in a rock, the assemblage of fossils within a rock and/or their relative abundance, can be used as an aid to the determination of relative geologic time.
d. Fossils are used as indicators of past environments which helps us in reconstructing the paleogeography of the ancient past.
Important Notes About Handling Fossils
If you are taking this course in a face-to-face setting (or simply examining fossils on your own), there are some important things to keep in mind.
1. The fossils you will be examining in the next few weeks may have survived up to 3 billion years prior to the lab and so are precious. You will be holding a piece of Earth’s history in your hands and you should treat it with the respect and care it deserves. Every one of these fossils is unique and if mistreated an important part of Earth’s 4.6 billion year history will have disappeared forever.
2. Please pay careful attention to the instructions about which fossils can be picked up from the tables and handled, and which samples may not be picked up and must be left on the table. Some fossils are so fragile that one lab session would destroy them if everyone picked them up. Do not test any specimens with acid.
3. Please be careful not to mix up the specimens or any corresponding boxes or labels. This leads to confusion for all the students who follow you and is unfair to them. If any specimen numbers become detached, tell the TA.
4. Due to the fragile nature of many of these fossils, the fossils put out in Labs 5 to 9 will not be available for study at other times. Photographs will be made available in the study guides, but you should take the time to finish these labs during the lab times while you can examine the original fossils.
5. Some of these specimens may belong to the private personal collections of individual members of the department who have graciously lent them. Specimens can be either expensive or impossible to replace. The Cambrian Burgess Shale fossils in Lab 6 are from a fossil locality in the Rockies so important that it is globally protected as a World Heritage Site. We are fortunate enough to have the last collection ever given out to a university department by the Government of Canada. These are quite literally, irreplaceable.
6. If you mistreat the fossils in these labs and end up breaking our departmental, personal or Burgess Shale specimens you will find yourself either (a) paying to replace them from your own pocket and (b) so far down both our and Santa’s naughty lists you will never get off. If any specimens are removed from the lab room, the tutoring room or any collection in the department, the matter will be treated as theft and dealt with accordingly.
This lab will introduce you to the starting materials from which fossils are derived, and the mechanisms by which they have been preserved in the stratigraphic record. We will start by examining a range of fossils and note some key features of both the rocks they occur in and of the fossils themselves. In this and following labs you will acquire skills related to (a) above, and begin to be able to recognize fossils from one location to another to aid in stratigraphic correlation.
Labs 6 to 8 will introduce you to the major fossils groups. We shall see most of the Kingdoms, many of the major Phyla within the animal kingdom, and for some fossils we may specify Class and Order. This can sometimes be a lot of information to process all at once so we will be introducing the major fossil groups over the next three labs. Sometimes this may not be in strict chronological sequence, but will reflect the order that they become important in Earth’s history.