Salt and Light

My background is in anatomy but I taught other science subjects as well and one of the topics that fascinated me was fossils because of their relationships to bones but fossils have a lot more diversity than just mineralized bones. Fossils come in all sizes: from one- micrometer (1 µm) bacteria to dinosaurs and trees, many meters long and weighing many tons. A fossil normally preserves only a part of the deceased organism, usually that portion that was partially mineralized during life, such as the bones and teeth of vertebrates, or the chitinous or calcareous exoskeletons of invertebrates. Fossils may also consist of the marks left behind by the organism while it was alive, such as animal tracks or feces (coprolites). These types of fossils are called trace fossils or ichnofossils , as opposed to body fossils . Some fossils are biochemical and are called chemofossils or biosignatures  All fossils have 3 things in common they are over 10,000 years old, they retain some characteris