Big Ideas
The study of past life
What is Paleontology?
The geologic age of a fossil, organism, rock or geologic feature or event defined relative to other organisms, rocks, or features or events rather than in terms of years
What is relative age?
Rocks formed through the cooling and solidification of magma or lava
What are igneous rocks?
The type of rock fossils are found in
What is sedimentary rock?
Evidence for the history of life on Earth, which supports the theory of evolution
What is the fossil record?
Someone who studies fossils
What is a paleontologist?
The idea that in any undisturbed sequence of rock layers the youngest layer is on the top and the oldest layer is on the bottom
What is the Law of Superposition?
Rocks that are subjected to high heat and pressure which causes a profound change in form
What are metamorphic rocks?
A fossilized footprint is an example
What is a trace fossil?
The process where a species comes to an end or dies out
What is extinction?
The age Earth was believed to be before James Hutton challenged it in the 18th century
What is a few thousand years?
Clues from igneous rocks to help date rock layers
What are intrusive and extrusive igneous rocks?
Rock formations from magma that cools and solidifies within the crust of the planet
What is intrusive igneous rock?
A fossil in which minerals replace all or some of an organism
What is a petrified fossil?
Group of extinct, segmented, hard shelled marine arthropods that lived over 520 million years ago
What is a trilobite?
The theory that sudden events, like a meteor hitting the Earth, and not gradual geologic processes shape the Earth's crust
What is Catastrophism?
Fossils that are useful in defining and identifying geologic time periods since they help date determine the relative age of rocks
What are index fossils?
Rock formations from magma that cools and solidifies above the surface of the crust
What is extrusive igneous rock?
A fossil that is formed when an object is placed into soft mud and is removed by decomposition or physical sources
What is a mold fossil?
Older rocks contain these types of organisms, supporting the idea that species change over time
What are simpler organisms?
The concept that the earth's surface was shaped in the past by gradual processes, such as erosion, and by small sudden changes, such as earthquakes?
What is Uniformitarianism?
A fracture in the ground that occurs when the Earth's tectonic plates move that is always younger than the rock it cuts through
What is a fault?
A gap in the sequence of rock layers due to erosion
What is unconformity?
A three-dimensional fossil formed when minerals fill up the imprint of a dead thing in the rock
What is a cast fossil?
Younger rocks contain these types of organisms, supporting the idea that species change over time
What are complex organisms?