The extinction of the dinosaurs occurred about 66 million years ago during the Cretaceous–Paleogene (K–Pg) event, when a massive asteroid impact near the Yucatán Peninsula triggered global climate collapse, wiping out nearly 75–80% of Earth’s species. Birds survived as the only living branch of dinosaurs, while mammals diversified afterward, reshaping Earth’s ecosystems.
Overview of the Dinosaur Extinction
Timeframe: ~66 million years ago, marking the end of the Cretaceous and the Mesozoic Era.
Severity: Eliminated nearly all dinosaurs except birds, along with many marine invertebrates.
Impact: Reset ecosystems, paving the way for mammals to dominate in the Cenozoic Era.
Causes of the Extinction
Asteroid Impact (Chicxulub Crater, Yucatán Peninsula)
Size: ~10–15 km wide asteroid.
Speed: ~64,000 km/h.
Effects: Released energy equal to 100 trillion tons of TNT.
Consequences:
“Impact winter” → dust blocked sunlight, halting photosynthesis.
Collapse of food chains.
Tsunamis up to 1,000 ft high and massive earthquakes.
Volcanism (Deccan Traps, India)
Massive lava flows released CO₂ and SO₂, intensifying climate change.
Contributed to long-term warming and ecosystem stress.
Pre-Impact Decline
Fossil evidence shows dinosaurs were already in decline in diversity before the asteroid hit.
Likely due to climate shifts and ecological instability.
Who Survived and Who Didn’t
| Group | Fate | |
|---|---|---|
| Non-avian dinosaurs | Extinct | |
| Birds (avian dinosaurs) | Survived | |
| Crocodilians & turtles | Survived | |
| Ammonites & belemnites | Extinct | |
| Corals & rudist bivalves | Mostly extinct | |
| Mammals | Survived, diversified |
Why It Matters
The extinction reshaped Earth’s biosphere, allowing mammals (including primates and eventually humans) to rise.
It highlights how sudden environmental shocks can devastate ecosystems.
Modern parallels: Climate change and biodiversity loss today echo some of these ancient patterns.
A set
of paleogeographic maps showing how Earth’s continents looked during the
Triassic, Jurassic, and Cretaceous periods.
🌍 Triassic (~250 million years ago)
Continents
were joined together as Pangaea, a single supercontinent.
Surrounded
by the Panthalassa Ocean and the Tethys Ocean.
🌍 Jurassic (~150 million years ago)
Pangaea
split into Laurasia (north) and Gondwana (south).
The
Atlantic Ocean began opening, while the Tethys Ocean lay between the two.
🌍 Cretaceous (~100 million years ago)
Continents
became more separated and recognizable: North America, South America, Africa,
Eurasia, India, Antarctica, Australia.
The
Atlantic Ocean widened, and the Tethys Sea shrank as India drifted northward.
DINOSAUR MASS EXTINCTION : DINOSAUR SPECIES 1) ANKYLOSAUR
DINOSAUR MASS EXTINCTION : DINOSAUR SPECIES 2) TRICERATOPS
DINOSAUR MASS EXTICTION SERIES: 6) AQUATIC DINOSAUR HUGE MESOSAURUS
VIRTUAL ANCIENT SCENE : MESOSAUR HUNT FOR THE SHARK AND ULTIMATELY GRAB THE SHARK INTO HIS MOUTH
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