Chapter 14, Problem 10STP

Summary Introduction

To describe:

The difference between petrified and replacement fossils

Introduction:

A fossil is any preserved evidence of an organism. Plants, animals and even bacteria can form fossils. More than 99 percent of the species that existed have become extinct. Only a small percentage of these organisms are preserved as fossils. There are six categories of fossils; trace, molds, replacement, petrified, amber and mummies.

Answer to Problem 10STP

In a replacement fossil the original material of an organism is replaced with mineral crystals that can leave detailed replicas of hard or soft parts whereas in petrified fossil the empty pore spaces are filled in by minerals such as in petrified wood.

Explanation of Solution

Replacement fossil- Minerals sometimes penetrate and replace the hard parts of an organism. The original material of an organism is replaced with mineral crystals that can leave detailed replicas of hard or soft parts. Example- A shell or a bone replaced with another mineral.

Petrified fossil- Sometimes the empty spaces are filled with minerals in the original organism. This is called petrified fossil. Example- A petrified stone or wood.