The duration of the earth’s history has been divided into smaller spans called the eras. The five eras are
- Archeozoic era ‘Pre-Cambrian period’
- Proterozoic era
- paleozoic era
- Mesozoic era ‘age of reptiles’
- Cenozoic era ‘age of the mammals’
- First mammal appeared 200 million ago in Triassic period.
- The Indian desert also known as Marusthali is believed to be under the sea during Mesozoic Era.
- The Tethys Ocean (Himalaya) was an ocean during Mesozoic Era.
- The angiosperms were developed in Coenozoic era.
List of archaeological periods
- Palaeolithic 1,000,000 BC to 10,000 BC – Ostrich egg
- Mesolithic 10,000 BC to 4,000 BC – microliths
- Neolithic 4,000 BC to 2,200 BC
- Bronze Age 2,600 BC to 700 BC
- Iron Age 800 BC to AD 43 AD
