The catastrophic event that cleared the path for the age of dinosaurs
The end of the Triassic Period was a time of profound biological upheaval. While some lineages vanished forever, a massive extinction event wiped out the competition, leaving behind a vacant world ripe for a new group of giants to claim dominance.
Occurring approximately 201.5 million years ago, the end-Triassic extinction ranks as the fourth most severe extinction event in Earth's history [S3:p3]. This global catastrophe resulted in the loss of roughly 76 percent of all terrestrial and marine species, as well as about 20 percent of all taxonomic families [S3:p2]. While it was less devastating than the Permian-Triassic 'Great Dying'—which eliminated over 95 percent of marine life—it fundamentally restructured the planet's ecosystems [S3:p4].
The mechanism behind this collapse remains a subject of intense scientific debate [S3:p6]. Many researchers point to massive climate shifts driven by the rifting of the supercontinent Pangea [S3:p7]. This geological movement, specifically where northwestern Africa met eastern North America, may have released as much as 100,000 gigatons of carbon dioxide [S3:p7]. Such a surge likely intensified the greenhouse effect, potentially raising global temperatures by 10 to 15 °C and causing ocean acidification [S3:p7]. Some scientists also suggest that this warming could have triggered the release of methane from undersea ice and permafrost [S3:p8].
Evidence from flood basalts suggests a 620,000-year window of volcanic activity [S3:p8]. The most intense period of volcanism occurred during the first 40,000 years of this interval, coinciding with the onset of the extinction [S3:p8]. In the oceans, groups like conodonts and certain ammonoids perished, though phylloceratid ammonoids survived to drive later cephalopod radiation [S3:p5]. On land, the transition was less lethal for certain groups; dinosaurs, crocodiles, and mammals were relatively unaffected, allowing them to quickly occupy the ecological niches left vacant by the disappearance of other vertebrate fauna [S3:p6].
Source: Could You Survive The End-Triassic?
