magnetotactic organisms are prokaryotic, with only one example of giant-magnetofossils, likely produced by eukaryotic organisms, having been reported. magnetotactic bacteria, the source of the magnetofossils, are magnetite (feo) or greigite (fes) producing bacteria found in both freshwater and marine environments. these magnetite bearing magnetotatic bacteria are found in the oxic-anoxic transition zone where conditions are such that oxygen levels are less than those found in the atmosphere (microaerophilic). compared to the magnetite producing magnetotactic bacteria and subsequent magnetofossils, little is known about the environments in which greigite magnetofossils are created and the magnetic properties of the preserved greigite particles.