Unit 5 Lesson 1 What is a Fossil?
index fossil
A fossil of a type of organism that lived in many places during a relatively short time span.
Pangae;
Long ago, all of Earth's land formed one giant continent.
What features of the fossil might help you determine what kind of fossil it is?
Look at its size, shape and parts
Era
A major division of geological time composed of a number of periods and is marked by distinctive character or events.
cast
A model of an organism, formed when sediments fills a mold and hardens.
mass extinction
A period in which a large number of species become extinct.
period
A series of years by which time is measured.
fossil record
All the fossils in Earth's rock layers containing information about Earth's history and the history of life on Earth.
mold
An impression of an organism, formed when sediment hardens around the organism.
Geologic Time Scale
Divides earth's history into manageable units. The fossils each unit contains defines that unit.
living fossils
Organism that look as if they have not change much over time.
Relative age
The age of a layer of rock when you compare it to other layers.
eon
The largest division of geologic time is an indefinitely long period of time.
What might a scientist infer from a plant that has remained unchanged for a long time?
The plant existed in an area that had a very stable environment.
fossil
The remains or traces of a plant or animal that lived long ago.
paleontology
The science of the forms of life existing in former geologic periods, as represented by their fossils.
Which type of fossil would more closely resemble how an organism looked in life - a mold or a cast?
a cast would more closely resemble how an organism looked.
epoch
any of several divisions of a geologic period during which a gelogoic series is formed. A point of time distinguished by a paricular event or state of affairs.
Ohio fossils are
brachiopod, cephalopod, trilobite, and horsetail plant fossils
What happens to living things when they die?
decompose, wash away, get eaten or get buried
Most fossils are found in
sedimentary rock.
Trace Fossil
shows how an organism lived.
Fossils help us
understand Earth's history.
