Upload
melva
View
75
Download
0
Tags:
Embed Size (px)
DESCRIPTION
Fossils Chapter 21.4. fossil : remains or evidence of living things. (1) original remains : the actual, unchanged remains of the organism are preserved. (a) frozen in ice. (b) preserved in amber(tree sap that has hardened. (c) mummification. - PowerPoint PPT Presentation
Citation preview
FossilsChapter 21.4
fossil: remains or evidence of living things
(1) original remains: the actual, unchanged remains of the organism are preserved
(a) frozen in ice
(b) preserved in amber(tree sap that has hardened
(c) mummification
(2) replaced remains: soft parts of the organism have disappeared and been replaced by minerals
petrification
(3) molds and casts of the original organism(4) trace fossils: evidence of life other than remains of an organisms activities and/or appearance
(a) footprints
(b) imprint
(c) tracks, trails, burrows, borings
coprolites: fossilized dung or waste materials from ancient animals
T-Rex Carnivore Coprolite (8 lbs.)
gastroliths: fossilized stone found within the digestive system of a dinosaur or other reptile
index fossil: fossils found exclusively in rock record of a particular geologic age•must have (4) characteristics:(1) must be easily recognizable(2) must be widespread in occurrence(3) must be limited in time(4) must be found in large numbers with the rock layer