a human or animal that lived in the past from which others have developed

• predator

• internal

• external

• ancestor

record of all the fossils ever discovered on Earth

• fossil record

• geologic time scale

• historical record

• geologic record

a chart that divides Earth’s history into different time units based on changes in the rocks and fossils

• earth history

• fossil record

• geologic time scale

• historical time scale

event that occurs when the last individual organism of a species dies

• extraction

• extinction

• evolution

• eradication

a fossil that has characteristics of both ancestral organisms and organisms that evolved later

• fossil

• transitional fossil

• index fossil

• fossil mold

the study of similarities and differences among structures of different species

• comparative anatomy

• transitional fossil

• embryology

• vestigial structure

body parts of organisms that are similar in structure and position but different in function

• vestigial structure

• analogous structures

• homologous structures

• heterologous structure

body parts of organisms that are similar in function but different in structure

• vestigial structure

• analogous structures

• homologous structures

• heterologous structure

body parts of organisms that has lost its original function through evolution

• vestigial structure

• analogous structures

• homologous structures

• heterologous structure

the science of the development of embryos from fertilization to birth.

• physiology

• embryology

• biology

• geology