Definitions
_________ is the death of every member of a species
Extinction
Name the time in Earth's history: Clue #1- When the surface was covered in lava Clue #2- it was the first eon.
The Hadean eon
True/False: Humans have existed for almost all of Earth’s history?
False
The largest division of geologic time are ______________.
Eons
How did scientists know what dinosaurs looked like?
They examine fossil evidence.
___________ is the extinction of many species at the same time
Mass extinction
Name the time in Earth's history: Clue #1: 251 million years ago Clue #2: Age of Reptiles
The Mesozoic era
How is the geologic time scale of Earth’s history divided?
It is divided by major events or changes that mark new era's.
Eons are divided into __________.
Eras
The earliest fossils scientists found were of...
Unicellular organisms
What is a rotating, flattened structure of gas and dust spiraling toward a massive central body called?
An accretion disk
Name the time in Earth's history: Clue #1: 65 million years ago to today Clue #2: fossils are in the top layer
The Cenozoic era
True/False: Throughout Earth’s history, the number and type of organisms has stayed about the same.
False
Eras are divided into __________.
Periods
A fossil is an object that contains traces, remains, or evidence of ..
Living things from long ago
The oldest sections are shown on the __________ of a time scale, and the newest sections would be on the ________ of a time scale.
Bottom; Top
What was the event that occurred 66 million years ago when a 10km wide asteroid struck Earth and wiped out the dinosaurs?
The Great extinction or the Cretaceous extinction
What dinosaur was called the “Lion of the Jurassic,” this predator grew in size alongside its prey, the Brachiosaurus.
The Allosaurus
Periods are divided into ____________.
Epochs
Evidence of this early photosynthetic life form first appeared during the Eoarchean and Mesoarchean eras.
Cyanobacteria
This event was the relatively rapid appearance (over a period of many millions of years) of many animal and plant species.
The Cambrian explosion
The first trace of life on earth can be traced back to..
3.8 billion years ago.
Give an example of creatures that were victims of a mass extinction
Dinosaurs
There are _____ eons in Earth’s history.
Discovered to have existed 3.8 billion years ago, these were among the first prokaryotic life forms found.
Anaerobic bacteria