Dinosaurs (the non-bird ones) went extinct about 66 million years ago, at the end of the Cretaceous period, most likely due to a massive asteroid impact that triggered global climate catastrophe.

Quick Scoop: When Did the Dinosaurs Go Extinct?

Scientists agree that the classic “big dinosaurs” disappeared around 66 million years ago , at the boundary between the Cretaceous and the Paleogene periods.

In rocks younger than this age, paleontologists have not found confirmed fossils of non‑avian (non‑bird) dinosaurs.

The Timeline in a Nutshell

  • Dinosaurs first appeared over 230 million years ago and dominated Earth for more than 160 million years.
  • Their reign ended in a mass extinction event at about 66 million years ago.
  • This event marks what geologists call the Cretaceous–Paleogene (K–Pg) boundary.

You can imagine a calendar of Earth’s past where dinosaurs rule for months, and then in the last “day,” most of them vanish in a geologic instant.

What Caused the Extinction?

The leading explanation is a huge asteroid impact , with additional debate about how much massive volcanic eruptions contributed.

1. The Asteroid Impact (Main Suspect)

Most researchers point to a roughly 10 km wide space rock that slammed into what is now the YucatĂĄn Peninsula in Mexico, forming the Chicxulub crater.

Key pieces of evidence include:

  • A thin global layer of clay rich in iridium , a metal more common in asteroids than in Earth’s crust.
  • Shocked quartz and tiny glassy droplets (tektites) formed by ultra‑high‑energy impacts.
  • A huge buried crater at Chicxulub that is the right size and age.

What likely happened next:

  • Firestorms near the impact site from superheated ejecta.
  • Earthquakes and mega‑tsunamis.
  • Dust, soot, and aerosols in the atmosphere, blocking sunlight.
  • A collapse of photosynthesis, food chains, and climate—something like a “nuclear winter” scenario on a planetary scale.

This chain reaction is sufficient to explain the loss of around 75% of all species , including non‑avian dinosaurs.

2. Massive Volcanic Eruptions (Supporting Role?)

At roughly the same time, enormous volcanic eruptions in what is now India produced the Deccan Traps , vast layers of lava spread over hundreds of thousands of square miles.

  • These eruptions could have released huge amounts of carbon dioxide and other gases , warming the climate and stressing ecosystems before or during the impact period.
  • Some scientists argue volcanism weakened ecosystems so the asteroid delivered the final blow, while others see volcanism as secondary to the impact.

Most current research still favors the asteroid as the primary killer, with volcanism as a possible aggravating factor.

Did All Dinosaurs Go Extinct?

Here’s the twist: not every dinosaur lineage vanished.

  • All non‑avian dinosaurs (T. rex, Triceratops, sauropods, etc.) went extinct around 66 million years ago.
  • Avian dinosaurs —the group we simply call birds —survived and diversified after the catastrophe.

So in a technical sense, dinosaurs are still around today as birds , even though the giant land‑dwelling forms disappeared at the K–Pg boundary.

Forum & “Latest News” Angle

In recent years, there’s been lively discussion in scientific papers and online forums about the fine details : how fast the extinction unfolded, how much volcanism mattered, and whether some dinosaur remnants lingered briefly after the main event.

  • Some paleontologists point to rare fossils that might hint at dinosaurs very shortly after the impact, but these are usually explained as older fossils reburied in younger rocks.
  • Discussions often revolve around whether the extinction took place over years, centuries, or a bit longer—but all within a geologically “instant” window near that 66‑million‑year mark.

From a “trending topic” perspective, new studies keep refining how the last day, months, and years of the dinosaurs looked—temperature swings, wildfire spread, atmospheric chemistry—but none of this challenges the core date: about 66 million years ago.

Tiny TL;DR

  • Non‑avian dinosaurs went extinct about 66 million years ago , at the end of the Cretaceous period.
  • The main cause was a giant asteroid impact , likely intensified by large‑scale volcanic activity.
  • Birds are the surviving dinosaur lineage and are still with us today.

Information gathered from public forums or data available on the internet and portrayed here.