Particle.news
Download on the App Store

Ordovician Mass Extinction Set the Stage for the Rise of Jawed Fishes

A new global fossil database tracks how survivors in isolated hotspots diversified before spreading worldwide.

Overview

  • A peer-reviewed Science Advances study published January 9, 2026, by Wahei Hagiwara and Lauren Sallan of OIST links a major die-off to vertebrate dominance.
  • Researchers synthesized roughly 200 years of late Ordovician–early Silurian fossil records to quantify genus-level diversity and map species distributions.
  • The extinction unfolded in two pulses, with rapid cooling then warming, followed by a gradual but marked rise in gnathostome diversity over millions of years.
  • Analyses identify refugia as diversification engines, highlighting South China for early full-body fossils of jawed fishes that later dispersed globally.
  • The team outlines a recurring "diversity-reset cycle" in which ecosystems rebuild with new taxa, while key drivers of the extinction and later gnathostome supremacy remain unresolved.