Thurgood Marshall Middle School
- Fossil – a trace or the remains of a once-living thing from long ago
- Index Fossil – a fossil of an organism that was common, lived in many areas, and existed only during a certain time span of time. Index fossils are used to help determine the age of rock layers.
- Trace Fossil – not part of an animal or impressions of it, but rather evidence of an animal’s presence. Trace fossils may include footprints, trails, animal holes, burrows, and even feces.
- Stratum or strata (plural) – layers of sedimentary rock or soil, perhaps even igneous layers
- Absolute age – the actual age in years of an event or object
- Relative age – the age of an event or object in relation to other events or objects
Types of Fossils
SciShow Fossils Video Playlist