What is a Fossil?
A fossil is defined as the naturally preserved
evidence of past life. The evidence can be direct, in other
words, parts of the plant or animal, or indirect, for example a
footprint or burrow. The term “past” is imprecise; most
paleontologists (the discipline of geology that studies fossils)
consider this to be older than the Holocene Period, or older than
10,000 years. The naturally preserved part of the definition
means that the processes of human activity, such as burial or
mummification, do not produce fossils. There are two categories
of fossils, body fossils, or fossils of all or part of an
organism's body, and trace fossils, evidence of an organism's existence
and behavior.
The examination of both categories of fossils
naturally brings about questions on preservation, many of which can be
utilized in inquiry based exercises in the classroom setting.
Some of these questions may include: (1) what part or parts of the
organism are most likely to be preserved? (2) by which means will
the organism be preserved? and, (3) to what extent can we hypothesize
about the behavior and ecological preferences of the organism?
Professor Connie Soja has published an article
in the Journal of
Geologic Education on the study of Taphonomy (the study of the burial
and preservation of fossils) in the classroom (link below). This
publication outlines a laboratory exercise where students bury several
types of easily acquired food items (for example, fish, clam
shells, mushrooms, ect) into the ground, and then exhuming them
several weeks later to
examine the condition of their preservation. The study of
Taphonomy is a useful tool when discussing the processes involved with
preserving organisms, and the limits of the fossil record.
To examine the two categories of fossilization in more detail click
here (www.zoomschool.com)
To download Connie Sojas article click
here
(JGE-ExperTaphonMs.pdf)
