Earth History Flashcards
Earth History
How long ago did the earth form?
4.5 billion years
Earth History
How long ago was the moon created from the earth?
4.5 billion years
Earth History
How long ago did water form on earth?
4.4 billion years
Earth History
How long ago did prokaryotic life first arise on earth?
4 billion years
Earth History
The moon is a piece of what?
The earth crust/mantle
(ejected after a protoplanet crashed into the newly-formed earth)
Earth History
How long ago did photosynthesis first begin on the earth?
3 billion years
Earth History
How long ago did unicellular eukaryotic life first arise on earth?
2 billion years
Earth History
How long ago did multicellular eukaryotic life first arise on earth?
1.5 billion years
Earth History
The great oxidation event (the massive increase in oxygen in the earth’s atmosphere) 2.5 billion years ago occurred due to the rise of what?
Cyanobacteria
Earth History
What do we call the period in earth history prior to the arrival of life?
The Hadean
Earth History
What is the name of the period of earth history after the arising of life but before eukaryotes?
The Archaean
Earth History
What is the name of the period of earth history during which eukaryotes first arose and flourished?
The Proterozoic
Earth History
The Hadean, Archaean, and Proterozoic eons can all be referred to collectively as what?
The Precambrian
Earth History
Photosynthesis began on earth (and thus oxygen proliferated) in which Eon of the earth’s history?
The Proterozoic
Earth History
The Proterozoic Eon is a time when the earth became oxygen-rich, the ozone layer developed, and what form of life first appeared?
Eukaryotes
Earth History
What long-term event started approximately 500 million years ago and is the time when practically all major animal phyla started appearing in the fossil record (wide variety of plants, sea life, insects, amphibians, etc.)?
The Cambrian explosion
Earth History
What period predates the Cenozoic era and encompasses the Triassic, Jurassic, and Cretaceous periods?
(250 million years ago to 66 million years ago)
The Mesozoic Era
Earth History
How long ago was the extinction event that ended the dinosaurs?
66 million years
Earth History
Which era began 65 million years ago (to present) and is the time during which the earliest forms of modern animals began appearing?
The Cenozoic era
Earth History
What is the holocene?
The current geological epoch which began approximately 11,650 years ago
