Humans Evolved During the __________ Era/Eon

Q41: Dinosaurs evolved during the _ Era.

Q42: _ _ refers to time measured in

Q43: The longer the time span that a

Q44: The principle of _ _ states that

Q45: Volcanic eruptions eject _ _ into the

Q47: A/an _ is an unconformity in which

Q48: The principle of crosscutting relationships states that

Q49: Precambrian refers to all the time before

Q50: The earliest fossils have been found from

Q51: An unconformity in which tectonic activity tilted