Chapter 21.3, Problem 2C

Summary Introduction

To determine: The correct order of appearance of reptiles, mammals, amphibians, and fishes in the fossil record starting with the earliest.

Concept introduction: Molecular systematics helps the biologist to interpret the fossil record to assume the evolutionary history of animals. The scanty availability of fossils is always an obstacle for the biologist to detect the rate of divergence, age, and the number of branches of the animal groups. The fossils are precious data that can reconstruct the history of many living organisms. They are used to record the occurrence and evolution of living organisms in a geographical time scale.