Diverse and full of sea life, the Earth's Devonian era—taking place more than 370 million years ago—saw the emergence of the first seed-bearing plants, which spread as large forests across the continents of Gondwana and Laurussia.

However, a mass extinction event near the end of this era has long been the subject of debate. Some scientists argue the Late Devonian mass extinction was caused by large-scale volcanic eruptions, causing global cooling. Others argue a mass deoxygenation event caused by the expansion of land plants was to blame.

A recently published study in the journal Communications Earth & Environment led by researchers at IUPUI now posits that both factors played a role—and draws attention to the environmental tipping points the planet faces today.