Very large or heavy
Massive
In a way that does not take a lot of time
Briefly
Someone who studies the history of the Earth
Paleontologist
Sharing qualities with something not the same
Similar
Most likely
Possible
The process of finding things similar or different
Comparison
To appear in the world
Exist
A small piece of a larger object
Fragment
Extra
Additonal
An animal or plant preserved in rock
Fossil
Roughly; about
Approximately
To begin to grow
Sprout
Very old
Ancient