If an external mold later fills with sediment or minerals, it can form a cast. Trace fossils are other kinds of evidence that an organism existed. Trace fossils include tracks, trails and footprints; ...

Life on Earth looks good for its age. Newly discovered fossil records hint that mold-like unicellular organisms — the common ancestor to all complex life on our planet — arrived over a billion ...

Fossils can be broadly divided into body fossils and trace ... of recrystalization in substances like old honey or maple syrup. In the Kits: #3: Brachiopod Molds - Sometimes after an organism gets ...