The Neoarchaean (Neoarchean) is the last geological era in the Archaean eon. It began 2.8 billion years ago and ended 2.5 billion years ago. Before the Neoarchaean era was the Mesoarchaean era and before the Palaeoproterozoic.
Oxygenic photosynthesis first evolved in this era. This led to an oxygen catastrophe in the Palaeoproterozoic era. It was caused by a poisonous buildup of oxygen in the atmosphere. This was created by oxygen-producing photoautotrophs that evolved in the Neoarchaean. The supercontinent Kenorland formed during this period, about 2.7 billion years ago.