Fossils

November 16, 2004

Past Episodes


amber--	a fossil where the organism is trapped in resin and preserved whole
casts--	fossils formed when water containing minerals leaks into a mold. The minerals harden to form a copy of the original structure or organism.
classify--	Scientists classify the different types of living things into groups called species.
Cretaceous period-	a geological term denoting the interval of Earth history beginning around 144 million years ago and ending 66 million years ago
Cretaceous-Tertiary boundary--	a major stratigraphic boundary on Earth marking the end of the Mesozoic Era, best known as the age of the dinosaurs. The boundary is defined by a global extinction event that caused the disappearance of the majority of all life on Earth. (see the geologic time scale)
fossil--	the remains of an animal and plant, or the record of its presence, preserved in the rocks of the Earth.
fossilization--	is the process that turns a once living thing into a fossil. Only a tiny number of all the animals and plants that ever lived have been fossilized.
fossil record--	all of the fossils that have existed throughout life’s history
geologic maps--	maps that show the types and ages of rock of an area. These maps are used by paleontologists to find areas that are likely to contain fossils.
geologic time scale--	a calendar of Earth's history
impressions--	prints or marks made when an organism’s body has been compressed (flattened).
invertebrates--	animals without backbones. 95% of all living animalsare invertebrates. And there were even more in the past.
matrix--	the rock that surrounds the fossil
microfossil--	a very small fossil, best studied with the aid of a microscope
mineralization--	the process of replacing any organism’s original material with a mineral
Paleobotany--	the specific study of fossil plants, algae, and fungi
Paleontologists--	the scientists who study the remains of ancient life in fossils and the rocks they are found in
Paleontology--	the study of ancient life
radio-carbon dating--	method for determining the age of an organic substance by measuring the amount of the carbon isotope, carbon-14, remaining in the substance; It is usually used for determining ages in the range of 500 to 70,000 years.
sedimentary rock--	rocks that formed when layers of sediment such as clay, mud, silt, or sand hardened over millions of years. These types of sediments are laid down in lakes, swamps and oceans.
species--	Scientists classify the different types of living things into groups called species.
strata--	rock layers
trace fossil--	evidence left by organisms, such as burrows or footprints. Trace fossils are not preserved parts of the organism.
FOSSIL FACTS FASCINATING LINKS REFERENCES