Fossils

Cast

A fossil that is formed when an animal, plant, or other organism dies, its flesh decays and bones deteriorate; minerals gradually enter into the cavity.

What does the layers of rock (sediment) in the earth tell Paleontologists?

It tells how old the fossil is -Older fossils are in deeper layers of earth -Younger fossils are in a higher layers of earth

Trace fossil

Any indirect evidence of life preserved as an impression in rock; trails, footprints, tracks, burrows, and bite marks.

How animal fossils form

-Animal dies -Soft parts rot or decompose -Bone and teeth remains are buried under sediment -The remains are replaced with minerals and turn into rock -The earth slowly moves and cracks. -Wind/Weather (rain, snow, ice) expose the fossil

What does it mean if Paleontologist find fossils in the same place?

-They lived together if found in the same rock -They are the same age if found in the same layer

Index fossil

A fossil known to have lived in a particular geologic age that can be used to date the rock layer in which it is found.

Paleontologist

A scientist who studies fossils to learn about organisms that lived long ago

Extinction

A term that typically describes a species that no longer has any known living individuals.

Mold

A type of fossil formed when a shell or other hard part of an organism dissolves, leaving an empty space in the shape of the part.

Fossil

Any remains or trace of a formerly living organism preserved by a natural process.

Fossil record

Chronological collection of life's remains in sedimentary rock layers.

Carbonized fossil

Forms when organism are pressed between layers of rock or mud and when it decays, it leaves a carbon imprint on the rock.

Law of Superposition

In a sequence of layered rocks, the older rocks will be under the younger (newer) rocks.

Relative dating

Method of determining the age of a fossil by comparing its placement with that of fossils in other layers of rock.

Where are fossils usually found?

Sedimentary rock

Amber

Small animals, mostly insects, get stuck in tree resin. Resin is a sticky substance the comes from a tree. The resin hardens and becomes a fossil.

Petrification

The process by which organic material is turned into stone.

Petrified fossil

The soft parts of a once living thing is replaced by minerals.

Preserved fossils

When an organism gets trapped in tar, amber, or ice.

What are the different kinds of fossils?

petrified fossils, molds, casts, carbon films, trace fossils, and preserved organisms