{"id":793615,"date":"2026-05-13T14:31:16","date_gmt":"2026-05-13T14:31:16","guid":{"rendered":"https:\/\/www.europesays.com\/us\/793615\/"},"modified":"2026-05-13T14:31:16","modified_gmt":"2026-05-13T14:31:16","slug":"the-two-million-years-rain-crisis-that-helped-the-dinosaurs-take-over","status":"publish","type":"post","link":"https:\/\/www.europesays.com\/us\/793615\/","title":{"rendered":"The Two Million Years Rain Crisis That Helped the Dinosaurs Take Over"},"content":{"rendered":"

\"Illustration<\/a>Artistic representation of a Middle-Late Triassic landscape of southern Brazil. A large\u00a0Prestosuchus chiniquensis\u00a0<\/a>feeds on the carcass of a dicynodont <\/a>while individuals of\u00a0Parvosuchus aurelioi<\/a>\u00a0compete for scraps. Credit: Wikimedia Commons<\/p>\n

It\u2019s often called \u201cthe time it rained for two million years.\u201d That\u2019s not quite right, but the real story may be even stranger.<\/p>\n

Around 234 million years ago, Earth entered a long, uneven climate crisis known as the Carnian Pluvial Episode<\/a>. For roughly one to two million years, parts of the supercontinent Pangea swung from dry to intensely wet. As rainfall surged, rivers grew bigger and soils weathered faster. This affected many ecosystems across the planet.<\/p>\n

And when the turmoil passed, dinosaurs<\/a> were kings.<\/p>\n

Dinosaurs had already evolved before this event, but the Carnian crisis seems to have changed the world around them. It affected their competitors and broke existing food webs. In the chaos, dinosaurs found room to expand.<\/p>\n

A Gray Stripe<\/p>\n

The first clues were easy to miss.<\/p>\n

In Britain, geologists Alastair Ruffell and Michael Simms studied the famous red rocks of the Triassic<\/a>. Running through them was a grey band<\/a>\u2014the kind of sediment that shouldn\u2019t exist in a desert-like world. These rocks had formed in a mostly arid world, yet this layer hinted at wetter conditions. <\/p>\n

Other clues turned up elsewhere. In the Eastern Alps, researchers found pulses of sediment interrupting carbonate rocks. In plain English, this means rivers and runoff had suddenly become much more active. Similar signs<\/a> have since been reported from regions including Europe, China, South America, and beyond.<\/p>\n

Together, the rocks pointed to a major climate shift. Pangea had been mostly dry, then parts of it turned suddenly wetter. The phrase \u201cit rained for two million years\u201d gets the idea across, but oversells it. The evidence suggests repeated bursts of humid weather and heavy rainfall over roughly one to two million years.<\/p>\n

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Together, the rocks pointed to a major climate disruption. Pangea, the supercontinent that concentrated most of the planet\u2019s landmass, wasn\u2019t exactly a swamp. But across many regions, dry Triassic landscapes were repeatedly interrupted by bursts of humidity and heavy rainfall. Rain had come, and this surprised geologists.<\/p>\n

\u201cThe Carnian is a real problem,\u201d paleontologist Paul Olsen told Discover<\/a>. \u201cWe don\u2019t know it well.\u201d <\/p>\n

Volcanoes Behind the Rain<\/p>\n

The leading suspect is a vast volcanic province called Wrangellia<\/a>, remnants of which are now found in Alaska and British Columbia.<\/p>\n

During the Carnian, there were massive volcanic eruptions<\/a>. These eruptions pumped huge amounts of carbon dioxide into the air. That gas warmed the planet through the greenhouse effect. In turn, this meant warmer seas evaporated more water, moist air moved inland over Pangea, and monsoons unloaded heavy rains. These may have been some of the strongest rains our planet ever witnessed.<\/p>\n

\u201cThe eruptions peaked in the Carnian,\u201d Jacopo Dal Corso, of the China University of Geosciences, explained. \u201cI was studying the geochemical signature of the eruptions a few years ago and identified some massive effects on the atmosphere worldwide. The eruptions were so huge, they pumped vast amounts of greenhouse gases like carbon dioxide, and there were spikes of global warming.\u201d<\/p>\n

A 2024 study from North China found four separate pulses<\/a> of increased chemical weathering\u2014the breakdown of rocks by warm, wet conditions\u2014tied to volcanic signals and carbon-cycle disturbances during the Carnian Pluvial Episode.<\/p>\n

Rain, in other words, was only the visible symptom. Beneath it was a whole Earth system convulsing.<\/p>\n

Extinction Opens Another Door<\/p>\n

\"\"<\/a>Credit: Pexels<\/p>\n

The Carnian was brutal, and most creatures living at the time would have struggled with the change<\/p>\n

Acid rain<\/a> may have stripped soils and battered plants. More rain meant more erosion, and rivers poured sediment and nutrients into lakes and seas, changing the waters\u2019 chemistry. A 2020 study estimated that about 33% of marine genera disappeared<\/a> during the crisis.<\/p>\n

But some groups seemed to relish this opportunity. <\/p>\n

\u201cThe new floras probably provided slim pickings for the surviving herbivorous reptiles,\u201d said Professor Mike Benton from the University of Bristol. \u201cWe now know that dinosaurs originated<\/a> some 20 million years before this event, but they remained quite rare and unimportant until the Carnian Pluvial Episode hit. It was the sudden arid conditions after the humid episode that gave dinosaurs their chance.\u201d<\/p>\n

On land, large herbivores and plant communities morphed. Dinosaurs, still in their infancy, were among the animals that expanded after the upheaval. A 2018 study linked the Carnian wet interval to a sharp rise in dinosaur diversity, abundance, and geographic spread<\/a>.<\/p>\n

It\u2019s not that the dinosaurs like the rain. It\u2019s more that the Carnian changed the rules of the game. Early dinosaurs weren\u2019t the ecosystem dominators we know today. Initially, they struggled to make a mark on their ecosystem. But when the ecosystems were disturbed and food webs were reshuffled, dinosaurs found openings that previous groups no longer held.<\/p>\n

By the Jurassic <\/a>and Cretaceous<\/a>, their descendants would dominate the land.<\/p>\n

A Muddy Reset<\/p>\n

The Carnian Pluvial Event also appears to have helped shape lineages that still surround us. Studies connect this interval with the rise or early diversification of major groups, including turtles, crocodilians, lizards, amphibians, mammal relatives, and the dinosaur line that eventually gave rise to birds.<\/p>\n

In the oceans, modern-like coral reefs and plankton communities also gained traction after the crisis. The turnover helped replace older reef builders with the coral groups that would become more familiar in later seas. Tiny plankton also diversified, reshaping marine food webs<\/a> from the bottom up.<\/p>\n

But some scientists warn that the dates are still too fuzzy in many places to prove that all wet layers formed at the same time. Others see the Carnian as one of life\u2019s great hinge moments.<\/p>\n

\u201cSo far, palaeontologists had identified five \u2018big\u2019 mass extinctions in the past 500 million years of the history of life,\u201d Jacopo Dal Corso from the China University of Geosciences added. \u201cWe have identified another great extinction event<\/a>, and it evidently had a major role in helping to reset life on land and in the oceans, marking the origins of modern ecosystems.\u201d<\/p>\n

Both views can be true. The rocks do not tell a simple comeback story. They show a messy pattern: climate stress wiped out many species, and the survivors expanded into the space left behind.<\/p>\n","protected":false},"excerpt":{"rendered":"Artistic representation of a Middle-Late Triassic landscape of southern Brazil. A large\u00a0Prestosuchus chiniquensis\u00a0feeds on the carcass of a…\n","protected":false},"author":3,"featured_media":793616,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[8],"tags":[157144,323899,285,142095,25052,16278,323900,265845,25054,66628,159,157151,67,132,68,323901],"class_list":{"0":"post-793615","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-science","8":"tag-carnian-pluvial-episode","9":"tag-carnian-pluvial-event","10":"tag-climate-change","11":"tag-coral-reefs","12":"tag-dinosaurs","13":"tag-evolution","14":"tag-fossil-record","15":"tag-mass-extinction","16":"tag-paleontology","17":"tag-pangea","18":"tag-science","19":"tag-triassic","20":"tag-united-states","21":"tag-unitedstates","22":"tag-us","23":"tag-wrangellia"},"share_on_mastodon":{"url":"https:\/\/pubeurope.com\/@us\/116567756347512602","error":""},"_links":{"self":[{"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/posts\/793615","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/comments?post=793615"}],"version-history":[{"count":0,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/posts\/793615\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/media\/793616"}],"wp:attachment":[{"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/media?parent=793615"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/categories?post=793615"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/tags?post=793615"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}