Warm Up 11/9

1. In what era do we currently live?2. What do the following prefixes mean:

Paleo- Meso- Ceno-

3. What is a fossil?4. Are fossils significant at all? Why

might we care about them?WARM-UPS DUE TODAY

Turn them in after notes today

Earth’s History in Fossils Fossils-clues to the past

Who examines fossils?Paleontologists are scientists who

excavate, examine, and research all types of fossils.

A fossil is the remains or evidence of a living thing.

Soft parts in organisms are not fossilized, instead they undergo decay.

◦ Decay- breakdown of dead organisms into the substances from which they were made.

Most fossils found in sedimentary rock. Being quickly covered by sediment doesn’t allow decay or other animals to destroy it.

http://media.collegepublisher.com/media/paper689/stills/tsnk29j2.gif

Earth’s History in Fossils Petrification

Petrification-Once living material is replaced by minerals, turning it to stone.

Replacement may occur if water dissolves material but minerals in water replace the material.

Ex. Petrified Forest in Arizona. The

wood has become petrified (has turned to stone!)

Earth’s History in Fossils Mold and Casts

A mold is the empty space left after decay that has same shape as organisms.

A cast is a mold that’s been filled in.

CAST

MOLD

Earth’s History in Fossils Imprints

An imprint is an impression made in soft mud that then hardens. Ex: Leaves, feathers, etc.

http://www.fossilmuseum.net/Fossil_Galleries/GreenRiverFossils/ZelkovaLeaf/PF016B.jpg

Archaeopteryx

Archaeopteryx?

Earth’s History in Fossils Preservation of Entire Organisms

Very rare. Three ways.1. Freezing-Sudden weather

changes preserve organisms before decay takes place.

Ex. Woolly mammoths and very early people.

National Geographic Baby Wooly Mammoth

Found in 2007 in Siberia, perfectly preserved with the exception of missing its hair and toenails. Video after notes!

2. Amber-Flies or insects get trapped in tree sap and it hardens.

Ex. Jurassic Park.

http://dsc.discovery.com/news/2007/10/08/gallery/amber_zoom.jpg

3. Tar pits-Huge pits of tar.

Usually near water: animals would go drink & fall in.

Ex. Bison, camels, wolves, vultures, saber-toothed cats

http://www.papermag.com/blogs/la%20brea%20tar%20pits.jpg

Warm-Up 11/131. What is the difference between a

mold and a cast?2. How was Uba (the baby woolly

mammoth) preserved? 3. What is petrification?4. What can fossils tell us?

Reading 10min

Library on Thursday

Earth’s History in Fossils Trace Fossils

Trace fossils mark or give evidence of activities of organisms.

Ex. Tracks, trails, footprints, burrows.

https://courseware.e-education.psu.edu/courses/earth105new/graphics/L02_fossil_hpl922.jpg

Earth’s History in Fossils Interpreting Fossils

Many different life forms have existed at different times through earth’s history.

Scientists believe for every organism alive today at least 100 have gone extinct.

Fossils show evolution, how earth’s surface has changed, past climates and appearance and activities of extinct animals.

http://naturalsciences.org/exhibits/permanent-exhibits/third-floor