AI Explain

• Archean Eon


  The second eon in the geologic time scale, spanning from 4 billion to 2.5 billion years ago. During this time, the Earth's crust began to form, and the first life appeared in the form of single-celled organisms.
• Paleozoic Era


  The first era in the Phanerozoic Eon, spanning from 541 to 252 million years ago. It is marked by the development of many major groups of animals, including fish, amphibians, reptiles, and the first land-dwelling animals.
• Mesozoic Era


  The second era in the Phanerozoic Eon, spanning from 252 to 66 million years ago. It is often referred to as the "age of dinosaurs" because dinosaurs were the dominant terrestrial vertebrates during this time.
• Cenozoic Era


  The current era in the Phanerozoic Eon, beginning 66 million years ago and continuing to the present day. It is often referred to as the "age of mammals" because mammals became the dominant land-dwelling animals during this time.