Biologia i geologia By __Elisabeth__ Period: 4550 BCE to 550 BCE Era Del Precambrià https://www.youtube.com/watch?v=EiJiLXgWkgw Period: 550 BCE to 245 BCE Era Palezoica https://www.youtube.com/watch?v=EhHwwV3kq-A Period: 245 BCE to 65 BCE Era Mesozoica https://www.youtube.com/watch?v=Tk0xzywJ934 65 BCE Era Cenozoica https://www.youtube.com/watch?v=pS57MAxvIWI