They would later form a dominant part of the world's flora during the Carboniferous period.

The other seven stages' owners' corporations were also formed during the period.

Western swing musicians also formed very popular big bands during the same period.

It was formed during the Late Cretaceous period 80 million years ago.

Craters that formed still later during the period of low impact rates are well preserved.

This crater is believed to have formed during the Copernician period, within the last 1.2 thousand million years.

They differ widely in age but were probably formed during the Tertiary period.

The canyon is believed to have formed 5 to 13 million years ago during the Miocene period.

This system was the only tropical storm to form in May during the period from 1992-99.

It formed during the latest period of glaciation roughly 10,000 years ago.