I don't know the plural of eon but the answer is more than 1 eon
Most scientists agree that there are 3 eras for every eon.
An eon is the longest division of geologic time, representing billions of years. Eons are further divided into eras, periods, and epochs to categorize Earth's history in more detail. The current eon that we are in is the Phanerozoic eon, which began about 540 million years ago.
eon>era>period
The oldest eon of geologic time is the Archaean Eon of the Precambrian period. The oldest rocks and fossils date from this time, about 3.8 to 2.5 billion years ago. (Prior to that, the Hadean Eon began with the formation of the Earth. No geologic record exists from the Hadean, during which the Earth cooled from its molten state.)
The end of the Precambrian Eon is marked by the beginning of the Phanerozoic Eon, approximately 541 million years ago. This transition is characterized by a significant increase in the diversity of multicellular life forms and the appearance of abundant fossils in the geological record.
The eon after the Hadean Eon is the Archean Eon. During this eon, significant geological and biological events took place, leading to the development of early life forms on Earth.
I am currently in the Phanerozoic Eon.
It was in the Phanerozoic Eon.
Paleozoic eon
It is the Phanerozoic Eon.
It is apart of the Phanerozoic Eon.
Eon Mora is 5' 4".
Eon McKai was born in 1980.
Eon London is 5' 7".
Hyundai Eon was created in 2011.
Modern Eon ended in 1982.
Modern Eon was created in 1978.