ch 14 Flashcards
Began 65 million years ago and still continues today. Mountain ranges were formed.
Cenozoic Era
chlorophyll-containing, photosynthetic bacteria thought to be one of Earth’s earliest lifeforms
Cyanobacteria
Longest subdivision in the geologic time scale that is based on the abundance of certain types of fossils and is subdivided into eras, periods, and epochs.
Eon
next smaller division of geologic time after the period; is characterized by differences in life-forms that may vary regionally
Epoch
Second-longest division of geologic time; is subdivided into periods and is based on major worldwide in types of fossils.
Era
division of Earth’s history units based largely on the types of life-forms that lived only during certain periods.
Geologic time scale
middle era of Earth’s history, during which Pangaea broke apart, dinosaurs appeared, and reptiles and gymnosperms were the dominant life-forms
Mesozoic Era
The process whereby organisms better adapted to their environment to survive and produce more offspring.
Natural selection
gradual accumulation of genetic changes in populations of organisms over time that results in the transformation of species into new ones.
Organic evolution
Era of ancient which began about 544 million years ago when organisms developed hard parts and ended with mass extinction about 245 million years ago
Paleozoic Era
Large ancient landmass that was composed of all the continents joined together.
Pangaea
Third-longest period in geologic time; is subdivided into epochs; characterized by the types of life that existed worldwide.
Period
Longest time period in history lasting from 4.0 billion years ago to 545 million years ago.
Precambrian time
Group of organisms that reproduces only with other
Species
organism with a three 10 bed exoskeleton that was abundant in Paleozoic oceans and is considered an index fossil.
Trilobite
