Topic: What is a fossil?

Target group

First grade of post‑primary school, extended range

Core curriculum

General requirements

I. Geographical knowledge.

1. Understanding of specialized concepts and the use of geographical terms.

V. Dynamics of geological and geomorphological processes: the most important events in the history of the Earth, minerals, the genesis and use of rocks, sculptural processes and their effects (weathering, erosion, transport, accumulation, mass movements), geological outcrop.

Specific requirements

1. understands the rules of determining the relative and absolute age of rocks and geological events.

General aim of education

The student will learn what fossils are, how they were created and what their meaning is.

Key competences

• communication in foreign languages;

• digital competence;

• learning to learn.

Criteria for success
The student will learn:

• What are the meanings of the terms: mineralization, fossilization, fossils, guide fossils;

• how can we determine the relative age of the tested samples on the basis of the presence of guide fossils.

Methods/techniques

• activating

  • discussion.

• expository

  • talk.

• exposing

  • film.

• programmed

  • with computer;

  • with e‑textbook.

• practical

  • exercices concerned.

Forms of work

• individual activity;

• activity in pairs;

• activity in groups;

• collective activity.

Teaching aids

• e‑textbook;

• notebook and crayons/felt‑tip pens;

• interactive whiteboard, tablets/computers.

Lesson plan overview

Before classes

• Students get acquainted with the content of the abstract. They prepare to work on the lesson in such a way to be able to summarize the material read in their own words and solve the tasks themselves.

Introduction

• At least a week before the planned lesson, the teacher instructs students to read the entire „What is a fossil?” lesson in the e‑textbook, watch films depicting the technique of making a model of fossils and casting organic objects. The teacher divides the class into small teams (4‑5 people) and instructs each group to prepare at home a model of sediment layers with fixed in a rock fossils and a cast of objects of organic origin selected by students (shells, nuts, etc.).

• The teacher determines the purpose of the lesson, informing students about its planned course.

• The teacher asks students what they mean by the terms: mineralization, fossilization, fossils, guide fossils. The selected student writes the correct definitions on the board. The teacher completes the information and provides explanations.

Realization

• The next stage of the lesson is the presentation of models made by particular groups, with an indication of „fossils”, which in each case can be used to determine the relative age of rocks as guiding fossils. Students can exchange models to study them - loupes and tweezers to remove „fossils” from the material will be useful.

• After „examining” the presented models and the fossils contained, the teacher asks students to evaluate their colleagues' models. He informs that the evaluation should relate to an interesting layout, workmanship and what could be done better.

• The teacher offers students to arrange a geological corner together. Exhibits will be made by students in the form of plaster castings of selected items. The teacher asks students to present their models and justify why they have just chosen such an object.

• The next stage is the individual work of students. The students carefully watch, among others photos of specimens of fossils included in the lesson, photographs in albums or textbooks and specimens collected in the studio (if exists). They discuss it with the teacher, and then do an interactive exercise consisting in matching signatures to photos of various fossils.

Summary

• The last stage of the lesson is a summary, used to systematize and consolidate the message and complete the notes.

• The teacher asks students to do the exercise 2 of the e‑textbook as homework.

Homework

• Listen to the abstract recording at home. Pay attention to pronunciation, accent and intonation. Learn to pronounce the words learned during the lesson.

• Make at home a note from the lesson using the sketchnoting method.

The following terms and recordings will be used during this lesson

Terms

Texts and recordings

What is a fossil?

One of the methods of researching history of the Earth is examining evolution of organisms. Appropriate data are provided by paleontology which deals with searching, analyses and comparison of remains and traces of life activity of various organisms, preserved in sediments in the Earth’s crust. In favourable circumstances, dead remains of organisms and traces of their life activity may have been covered with layers of various sediments which slowed down their decomposition. Subsequent processes were responsible for gradual mineralisation which is decomposition of organic substances (remains) to simple permanent inorganic compounds, and fossilisation (petrification) of hard parts of their bodies, e.g. shells Describing this process, we tell how organic remains have turned into stone, and sediment has transformed to solid rock. Tree trunks, leaves or seeds as well as shells, bones or even moulds of soft animal tissues, preserved in rocks, are called fossils. They usually maintain many details of anatomical structure of a specific organism.

For paleontologists, the most valuable fossils came into being from organisms which dwellt in a short period and yet appeared in widespread area, namely index fossils. Discovery of any such fossil enables precise determination of relative age of a rock where such fossil has been found. In such situation, we are certain that examined rocks could not have been formed earlier than fossils found within. As all trilobites (small marine animals found in sediments) became extinct around the end of the Permian, also marking the end of Paleozoic Era, we cannot find them in younger rocks. The same principle applies to ammonites or plesiosaurs which became extinct around the end of the Cretaceous, also marking the end of the Mesozoic Era.

• Trunks, leaves or seeds as well as shells, bones, and sometimes casts of soft tissues of animals, preserved in rocks, are called fossils.

• Scientists are eager to use fossils to establish the details of the original living environment of fossil organisms.