Coal Limestone Fossil Coral

The Organisms’ Chapter of the Rock Story Still needs revision. Get some coral for the kids to look at. Horn Coral in with fossils

Fossils can tell us about the history of life on earth. Fossils can tell us about the climate on earth. Fossils can help us date rock layers.

Frozen Amber (tree sap) Peat Bog Bones in rock Shell in rock Lightning

Gastroliths (stones to aid digestion) Coprolite (poo) Bite/gnaw marksTracksBurrows

Natural vs. Artificial? Pompeii, Italy

Plants that live in swampy/marshy habitats die and turn into peat. Peat is compressed over the course of millions of years and turned into coal.

Coral produces a hard structure that serves as a sort of skeleton. When each generation of corals die their “skeleton” is left behind, building up very slowly year after year. Coral Castle in Miami, FL

The Actual Animal (Polyp Stage of the Life Cycle) The Calcium “Skeleton” that builds up to form the rock.

Coral reefs are home to 25% of all marine species

Small marine invertebrates (salt water animals without backbones) use a good deal of calcium in their shells. The animal dies and the soft parts rot away but the shells remain and build up layer after layer. The shells are compressed and turned into limestone.

Limestone is made of dead coral and other sea shells

What we think the living organism may have looked like.

Rock layers can help date fossils and fossils can help date rock layers. Archaeopteryx is a very famous fossil.

Geologic Time Divisions Notable Fossils or Events Time Scale (Million years ago) Cenozoic Abundant mammals, including humans ,500 3,800 4,500 Mesozoic Cretaceous Dinosaurs, flowering plants, birds, mammals Jurassic Triassic Paleozoic Permian Gymnosperms Mass extinction Carboniferous Reptiles Devonian First amphibians, early insects Silurian Land plants Ordovician Fish Cambrian Marine invertebrates ---trilobites dominant Proterozoic Aquatic plants Archean Earliest life --- bacteria, algae Earth formed Geologic Time Scale