The historical record that is alive in common knowledge reaches back a few millennia.

Even the scientific and literary traditions that extend our temporal sense of the past usually focus on the period since complex life diversified — the Phanerozoic Eon, the last 540 million years.

The Roraima sandstone represents an era before any of that.

Before complex animals.

Before plant-covered land surfaces.

Before the oxygen atmosphere that made complex aerobic metabolism possible had fully established itself.

An era in which the continents had not yet taken anything like their current configuration, in which the sun was somewhat dimmer than today, in which the day was shorter because the Earth rotated more rapidly and the tidal friction of the Moon had not yet slowed it to its current pace.