Question | Answer |
Fossil | The remains of an acient organism preserved in rock |
Carbon Film | A thin coating of carbon left behind by a decayed animal |
Sedimentary Rock | A type of rock formed when particles of organisms and other rocks are cvemented together |
Trace Fossil | Things left behind by organisms, which shows what they did |
Mold | A hollow space where an organism was buried and dissolved |
Cast | A copy of an oganism's shape |
Petrified Fossil | A type of fossil where minerals replace all of an organism |
Paleontoligist | A scientist who studies fossils to learn about ancient organisms |
Scientific Theory | A well-tested concept that explains a wide range of observations |
Evolution | The theory that states that organisms change over time |
Extinct | An organism that has died out |
Relative Age | The age of a rock compared to rocks around it |
Absolute Age | The age since a rock formd |
Law of Superstition | The principle that states that rock layers are younger than thoses below it |
Extrusion | Igneous rock that has hardened above the surface |
Intrusion | Igneous rock that has hardened under the surfac |
Fault` | A break or crack in the Earth's surface |
Unconformity | Where young rock meets old rock |
Index Fossil | Fossils of organisms that have lived for a short tine |
Atom | The smallest particle where the substance is still that substance |
Element | A substance where all the atoms are the same and cannot be broken down into another substance |
Radioacive Decay | The process in which a radioactive element releases particles and energy |
Half-life | The time it takes for half of a radioactive element to decay |
Geologic Time Scale | The record of geologic events and organisms |
Era | The three units that divide the time between Precambrian and present |
Period | The unit of time that divides eras |
Vertabrate | An animal with a backbone |
Invertabrate | An animal without a backbone |
Amphibian | An animal that lives half its life in water and half of its life in land |
Reptile | A cold-blooded, egg laying vertabrate |
Mass Extinction | The extinction of several species at the same time |
Mammal | A warm-blooded vertabrate that feeds their young milk |