Card Set Information
vocab of science
542 million years ago and ended about 251million years ago
enirmous number of species died
Began 251 million years ago and ended about 65 million years ago.
Division of geologic time that began 65 million years ago and includes the present period.
Division makes up 88% of earth's history. the time interval that began with the formation of earth and ended about 542 million years ago
detailed fossil record may allow scienteist to divide a period into shorter time
Eras are divided into shorter time units
eon divided into shorter units
an ordered arrangement of rock layers that is based on the relative ages of the rocks and in which the oldest rocks are at the bottom.