Fossil evidence shows that toothed leaves were present in Bighorn basin during the Paleocene and Eocene, but not during the PETM. Which of the following explains the changes in the fossils over this time?
The rate of the temperature change during the Eocene was too fast, driving toothed plants to extinction.
The temperature change was slow enough during the Paleocene that certain species could migrate, then return when temperatures
returned.
The rate of the temperature change during the PETM was faster than during the other eras, driving toothed plants to extinction.
The temperature change was slow enough during the PETM that certain species could migrate, then return when temperatures
returned.