Question

how are eras and periods of the geologic time scale named? they are named for the places where geologists first described rocks or fossils from that time. their names are based on the names of scientists who discovered the rocks and fossils. they are named after plants and animals that lived during that time. their names are based on the number of centuries within that length of time.

Explanation:

Eras and periods of the geologic time scale are typically named for the places where geologists first described rocks or fossils from that time. For example, the Cambrian period is named after Wales (Cambria is the Latin name for Wales) where rocks of that age were first studied in detail.

Answer:

They are named for the places where geologists first described rocks or fossils from that time.