Fossil Formation Facts
What type of rock are most fossils found in?
Sedimentary rock
Fossils found in the deepest layers of rock are usually ___ than those near the surface.
Older
What do we call the preserved remains or traces of organisms that lived long ago?
Fossils
What is evolution?
The process by which species change slowly over long periods of time.
What part of an organism is most likely to become a fossil?
Hard parts like bones, teeth, and shells.
What must happen to an organism’s body before fossilization can begin?
It must be buried quickly by sediment
What is the method called when scientists determine a fossil’s age based on its position in rock layers?
Relative dating
What is an imprint fossil?
A mark or impression left behind, like a footprint or leaf print.
How does the fossil record provide evidence for evolution?It shows gradual changes in species over time.
It shows gradual changes in species over time.
What is the name of scientists who study fossils?
Paleontologists.
Why don’t soft parts of organisms usually fossilize?
They decay too quickly
What is the method called when scientists determine a fossil’s actual age using radioactive elements?
Absolute dating
What term describes when an entire species no longer exists on Earth?
Extinction
Why is extinction important to the story of evolution?
It allows new species to evolve and adapt, keeping life on Earth diverse over time.
If a fossil footprint is found, what can it tell scientists about the animal?
How the animal moved, its size, or how fast it walked or ran.
What are the small pieces of rock, minerals, or organic material that settle and harden over time called?
Sediment
If a fossil is found above another fossil in the same area, what can you infer about its age?
It’s younger than the fossil below it.
What term describes a fossil that shows traits of both an ancestor and a newer species?
Transitional fossil
Why do scientists compare ancient fossils to modern-day organisms?
To identify similarities that show how species are related and have evolved.
The fossil of Archaeopteryx had both feathers and teeth. Why is this fossil important?
It shows a link between reptiles (dinosaurs) and birds — a transitional fossil.
Describe the basic process of fossil formation from death to discovery.
The organism dies → soft parts decay → remains are buried in sediment → sediment hardens into rock → fossil forms and is later uncovered
Why are sedimentary rocks best for studying fossils compared to igneous or metamorphic rocks?
They form in layers that preserve fossils, while heat and pressure in the other two destroy remains.
What is the name for all the fossils ever found, organized by their age and type?
The fossil record
What can cause extinction to happen?
Natural disasters, climate changes, loss of habitat, or competition.
If a fossil of a fish is found on top of a mountain, what does that tell scientists about the Earth in the past?
That the area was once underwater and has since been uplifted by geological changes.