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New Zealand Fossils Lesson Plans

Lesson 3: Microfossils Activity

This activity may be done individually or ingroups. It is in two parts, lessons 3A and 3B.

Instructions for lesson 3A:

1. Read the information provided below about microfossils (small fossils thatneed a microscope for detailed study)

2. You are given some images of microfossils. These are highly magnifieddrawings of specimens of foraminifera from New Zealand rocks. Cut them outindividually and sort them into at least three groups showing roughly similarmorphology (shapes or patterns).

3. Depending on the appearance of the specimens, try to subdivide your initial

groups into smaller sub groups4. Once you have them organised, write down what methods you used to help

with your sorting process5. Discuss the morphological features that you have used. Were some

specimens harder to categorize than others? Are there other features that youmight have chosen that would make your groupings simpler? How does yourclassification compare with that of others in the class?

Extension:

6. Draw a graph or diagram to represent your information.7. Make inferences on what is the most common group and the least common

group from your data. Compare and discuss your results with those of othersin the class.

MICROFOSSILS READING

Microfossils are particularly useful in paleoecology (the study of past ecosystemsand environments). They are often abundant in sediments that have fewmacrofossils, and they provide detailed information about the environments in whichthey were living. They are also very useful for finding out the age of rock layers avital aspect of geological mapping and the search for oil, gas and other resources.

Common microfossil groups, all of which have parts that preserve well in sediments,are the foraminifera, diatoms, radiolarians, spores and pollen.

Foraminifera aremostly less than 1 mm in size, althoughsome species can be several cm across. They are singlecelled with a calcium carbonate test (shell). As well as beingused to study evolution and the ages of rocks,they areuseful for reconstructing past changes in seawatertemperature, ocean circulation patterns and sea level.

Magnified Image: Foram

You will need: Images of microfossils that go

with this activity Scissors Glue Exercise book or paper

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Siliceous diatoms live in all aquatic (fresh and salt water) environments, and evenmoist soil. They can be used to research habitats ranging from the open sea tolagoons, rivers and lakes

Magnified Image: Diatom

Radiolarians are geometrically patterned single celled animals with spiky structuresmade of silica

Magnified Image: Radiolarian

Spores and pollen grains can often be linked directly to a livingplant, so identification of numerous grains in a sample allows

geoscientists to reconstruct local and regional vegetation.Changes in past vegetation patterns can be analysed for likelycauses, such as climatic factors like rainfall and temperature.

Magnified Image: Pollen

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