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The preserved remains or traces of an organism that lived in the past


the process of turning some plant material into stone by infiltration with water carrying mineral particles without changing the original shape


a fossil formed when an organism buried in sediment dissolves, leaving a hollow area


a type of body fossil that forms when crystals fill a mold or sediments wash into a mold and harden into rock


a hard yellowish to brownish translucent fossil resin


impressions left by an organism

Tar Pits

formed when a dark sticky form of oil seeps up from underground causing animals to get stuck.


A vertebrate possessing two pairs of limbs, such as amphibians, reptiles, birds, and mammals.


Scientists who study fossils

Trace Fossils

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


developed and changed over a long period of time


having two feet

Geologic time scale

scale used by paleontologists to represent evolutionary time, Earth's history organized into four eras: Precambrian, Paleozoic, Mesozoic, and Cenozoic

Radioactive dating

a technique used to determine the actual age of a fossil on the basis of the amount of a radioactive element it contains


a white, radioactive metallic chemical element that weighs more than any other element in nature


a soft heavy toxic malleable metallic element


A being with 5 fingers on each hand and 5 toes on each foot

Homologous structures

Structures in different species that are similar because of common ancestry.

Flickr Creative Commons Images

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