Fossils & Geologic Time

This is produced when sediments fill in a cavity made when an object decayed

• mold
• cast
•  index fossil

Fossils of species that existed for short periods and were widespread

• uniformitarianism
• cyanobacteria
• index fossils

Process by which organisms with traits that are suited to a the environment survive.

• natural selection
• principle of superposition
• uniformitarianism

What is a cavity in rock made when an organism decayed

• mold
• cast
• fossil

 The oldest rocks are on the bottom and the rocks become progressively younger toward the top

• uniformitarianism
• natural selection
• principle of superposition
• index fossils

The principle that Earth’s processes occurring today are similar to those that did in the past.

• uniformitarianism
• natural selection
• principle of superposition
• cyanobacteria

What is a large ancient landmass?

• Pangaea
• Cyanobacteria
• Africa
• Jumanji

What are among the earliest life-forms on Earth?

• cyanobacteria
• mold
• bears
• sponges

What are the remains, imprints, or traces of once-living organisms?

• index fossils
• fossil
• mold
• cast

As ____ evolved, they changed Earth’s atmosphere by producing oxygen.

• cyanobacteria
• reptiles
• trilobites
• dinosaurs