History of Life on Earth Crossword Puzzle

QUESTIONS LIST:

• continental drift : the movement of the tectonic plates
• bio geography : movement of continents and their effect on the distribution of living organisms
• cenozoic era : (66 million years ago - present)
• paleontologists : scientists who study fossils from ancient times.
• geologists : scientists who study the surface of the earth.
• archaeologists : scientists who study the cultures and periods.
• anaerobic : did not need oxygen to survive
• anthropologists : scientists who study the human race, especially its origins.
• paleozoic era : (540 - 250 million years ago)
• ice age : thick layer of ice covers much of the earth
• precambrian : (4.6 billion - 540 million years ago)
• cyanobacteria : they removed carbon dioxide from the air and released oxygen
• mesozoic era : (250 - 66 million years ago)
• era : a division of time within an eon
• timescale : calendar of events
• period : subdivision of an era