Manash (Subhaditya Edusoft): DINOSAUR MASS EXTINCTION PAGE

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.

DINOSAUR MASS EXTINCTION : DINOSAUR SPECIES 1) ANKYLOSAUR