TuesdayJanuary 8, 2013

(Indirect Fossil Evidence; Index

Fossils)

The Launch PadTuesday, 1/8/13

List the eight general types of fossils.Direct - teeth, bones, shellsDirect - mummified fossils

Direct - amber-preservation fossils Modified - petrified fossils

Modified - replacement fossilsModified - mold and cast fossilsModified - carbonization fossils

Modified - impression fossils

The Launch PadTuesday, 1/8/13

Which of the following are probably not fossils?

AnnouncementsHappy Bubble Bath Day!

Announcements

I will be available after school today until

4:45.

Assignment Currently Open

Summative or

Formative?Date Issued Date Due Date Into

GradeSpeed Final Day

Quiz 14 S4 12/12 12/12 12/19 1/16

Recent Events in ScienceFirst Fossil Bird With Teeth Specialized for Tough Diet

Read All About It!www.sciencedaily.com/releases/201

3/01/130107082602.htm

Beak shape variation in Darwin's finches is a classic example of evolutionary adaptation, with beaks that vary widely in proportions and shape,

reflecting a diversity of ecologies. While living birds have a beak to manipulate their food, their fossil bird ancestors had teeth. Now a new fossil

discovery shows some fossil birds evolved teeth adapted for specialized diets.

A study of the teeth of a new species of early bird, Sulcavis geeorum, published in the latest issue of theJournal of Vertebrate Paleontology,

suggests this fossil bird had a durophagous diet, meaning the bird's teeth were capable of

eating prey with hard exoskeletons like insects or crabs. The researchers believe the teeth of the new specimen greatly increase the known

diversity of tooth shape in early birds, and hints at previously unrecognized ecological diversity.

Photograph of Sulcavis geeorum skull, a fossil bird from the Early Cretaceous (120 million-years-ago) of Liaoning Province,

China with scale bar in millimeters. (Credit: Photograph by Stephanie

Abramowicz)

Certain conditions favor fossil preservation. Rapid burial by silt or organic matter

Possession of hard parts

Fossils - Evidence of Past Life

Fossils - Evidence of Past Life Indirect Fossil Evidence

Tracks – animal footprints made in soft sediment that was later lithified.

Fossils - Evidence of Past Life Indirect Fossil Evidence

Burrows

Fossils - Evidence of Past Life Indirect Fossil EvidenceCoprolites – fossil dung and

stomach contents

Figure 11.13F

Fossils - Evidence of Past Life Indirect Fossil Evidence

Gastroliths – stomach stones used to grind food by some

extinct reptiles

Fossils and Correlation

The Principle of Fossil Succession was first proposed by William Smith

in the late 1700s.This principle states that fossils

succeed one another in a definite and determinable order.

Fossils - Evidence of Past Life

Determining the Ages of Rocks Using Fossils

Figure 11.14

Fossils and CorrelationIndex Fossils

Index fossils are fossils used to define and identify geologic

periods.They work on the premise that,

although different sediments may look different depending on the

conditions under which they were laid down, they may include

the remains of the same species of fossil.

Fossils - Evidence of Past Life

Fossils and CorrelationIndex Fossils

If the species concerned were short-lived (in geological terms, lasting a few hundred thousand years), then it is certain that

the sediments in question were deposited within that narrow time period.

The shorter the lifespan of a species, the more precisely different sediments can be correlated, and so rapidly evolving

types of fossils are particularly valuable.The best index fossils are common, easy-to-identify at species level, and have a broad distribution - otherwise the likelihood of finding and recognizing one in the two sediments is minor.

Fossils - Evidence of Past Life

Fossils - Evidence of Past Life

What is a Fossil? Crossword