One meaning of the statement "the present is the key to the
past," is that knowing about present day organisms can help to identify
fossils and to explain their behavior and ecology. The remains of present
day organisms are often better preserved than are fossils, so the former
contain much more scientific information.
In this lab, students will compare recent and fossil remains, and
distinguish their differences.
- Explain to the students that the remains of once-living modern
organisms have distinct key characteristics. These key characteristics
can help you identify fossil examples of the same kind of organism.
Discuss the key characteristics of "present" day organisms
compared to those of the "past." Include items like teeth,
bones, bark, and shells. Emphasize to your students that items like
blood, skin, hair, and clothes are not found from the "past"
- Instruct the students to observe and draw the specimens of recent
organisms. Help them observe details, so that they will be able to
compare the fossils and recent specimens. Use a hand lens or Swift GH
microscope to observe the specimens.
- Students should examine the fossils, and match each fossil with its
recent counterpart. After they make a correct match, have them again
draw the fossil.
Different fossil specimens have gone through different types of
fossilization. The characteristics listed below may be slightly
different from your specimens.
SHELL: Recent samples should have ridges, growth lines, and should be
whitish, with a hint of color. Fossil samples should be white and
embedded into rock; growth lines may be visible.
GASTROPOD: The recent samples are spiraled and colored. The students
should be able to count the spirals. The fossil sample should be
whitish, and often reveals the inside of the gastropod.
CORAL: The recent sample will be full of small holes, which were
inhabited by the living coral organisms. Some samples may be colored.
The fossils look very rocklike, and show only cross sections of the
inside of the coral.