Temperate deciduous forests establish
Northern vegetation reorganises into the seasonal broadleaf and conifer forests still recognisable today.
- When
- —
- Duration
- 11 million years
- Known to
- ± 2 million years
- Era
- Oligocene, Cenozoic
The subtropical vegetation that had reached far into the northern latitudes retreats, and in its place a temperate deciduous forest belt forms across North America, Europe and Asia — oaks, maples, birches, beeches and walnuts, dropping their leaves against a cold season that had not previously existed at those latitudes. Many genera become disjunct, surviving in eastern North America and eastern Asia but dying out in Europe, whose east-west mountain ranges block southward retreat. That asymmetry still shapes the three continents' floras.