Unit 6, Topic 1: Ancestry and Diversity Vocabulary

index fossil

• fossils of organisms known to have existed during a particular time period

• fossils that are found in multiple geological layers

• fossils that are only found in one specific location

• fossils that are used to date rocks of different ages

period

• a major division of geologic time characterized by distinctive fossils and rock formations

• a specific time frame in human history

• a unit of time used in physics

• a phase in the life cycle of a star

Paleozoic era

• a major interval of geologic time when primitive life was abundant

• the time when dinosaurs roamed the Earth

• the period of the first mammals

• the age of the first flowering plants

era

• a smaller division of geologic time

• a larger division of geologic time made up of multiple periods

• a type of rock formation

• a specific event in Earth's history

Cenozoic era

• the present era noteworthy for the rise of mammals

• the era dominated by dinosaurs

• the era of the first multicellular organisms

• the era characterized by the formation of supercontinents

epoch

• a subdivision of a period characterized by distinctive fossils and rock formations

• a geological time frame marked by significant climatic changes

• a type of rock formation that contains no fossils

• a period of time defined by human history and civilization

mass extinction

• an event where species vanish faster than normal

• a gradual decline in biodiversity

• a sudden increase in species population

• a natural disaster affecting only one species

radiometric dating

• the process of using the half-life of a radioactive isotope to determine the age of a sample

• a method for measuring the temperature of rocks

• a technique for dating fossils based on their location

• a way to estimate the age of a sample using carbon-14 only

rock record

• the history of the Earth's past recorded in the layers of rocks

• a collection of minerals found in a specific area

• the process of erosion and sedimentation over time

• the study of fossils and their distribution

Precambrian time

• the earliest eon of Earth's history

• a period of rapid dinosaur evolution

• the time when mammals first appeared

• the age of the first human civilizations