Before you play

What Deep Time Means

This figure asks when a prehistoric animal first shows up in the fossil record, in millions of years ago.

  • Higher numbers mean deeper time, not longer survival.
  • The value comes from Prehistoric-Wildlife time-period fields first, with structured fossil-range fallbacks when the page cache is thin.
  • A genus can be older than people expect even when its famous fossils come from a later stage.

Think first appearance, not peak popularity.