i managed to find a few
Mass extinction when a large number of species die out (become extinct) in the same time period
Eon the largest time break down (there have been 4)
Era the middle time break down (there have been 3 in the last eon)
Period the smallest time break down (there have been more than 10 in the last eon)
Cambrian period the period where we see a lot of early life (540 – 490 million years ago)
Half-life the time it takes for half of something radioactive to change into another form
Radioactive—an atom that gives off smaller parts
Radioactive dating using how much an object has of something radioactive compared to what it
breaks down to
Absolute dating using radioactive dating to find when an object came from
Relative dating using layers of rock to estimate when an organism lived compared to other
organisms
Fossil traces or imprints of living things preserved in rock
Imprint a mark made by pressure from an object
Trace evidence left by something that was there (like a footprint)
Decompose to break down into simple parts (to rot or decay)
Paleontologist someone who studies what happened in the past using fossils
