The plants and animals found in concretions recovered from the
Francis Creek Shale are some of the most exciting and important fossils that
have been found in the state of Illinois. These fossils are known as the Mazon
Creek fossils because they were originally found along Mazon Creek in
northeastern Illinois. The quality and diversity of fossils recovered
in Mazon Creek nodules makes these localities important worldwide. In most
fossil deposits only the hard parts of organisms (shells, bones, teeth, etc.)
are preserved. This means that in most fossil deposits only animals that have
hard parts are preserved.
Because of the unique conditions of
fossilization, Mazon Creek fossils frequently have both hard and softer parts
preserved. In addition, many soft-bodied organisms that do not usually
fossilize are preserved.
These factors mean that the fossils from Mazon
Creek provide scientists with an extraordinary view of biodiversity 300 million
years ago.
The Mazon Creek deposit is an example of a Lagerstätten.
This exhibit shows some of the more interesting and dramatic types of fossils
recovered from these remarkable deposits. The exhibit also contains a link to
the searchable Mazon Creek Fossil Database and a link to activities suitable
for interested individuals as well as teachers and their
students.