How long were Dinosaurs alive?
Dinosaurs were alive on Earth for more than 150 million years. They first appeared about 243 – 233 million years ago (during the Triassic period) and ruled the land until 65 million years ago (during the Cretaceous period) when an asteroid hit the Earth, probably followed by other catastrophes like Vulkan eruptions and drastic climate change, causing a mass extinction that wiped out most dinosaur species. It’s also possible that further effects, such as acid rain, helped cause ecosystem destruction.
The Cretaceous–Paleogene extinction event is this impact, or “K–Pg extinction event.”
Only some small animals survived the impact.
This extinction affected even the large marine reptiles such as mosasaurs, plesiosaurs, and ichthyosaurs.
Not a single dinosaur fossil exists that is younger than 65 million years. This shows that there were no dinosaurs anywhere on Earth after the impact.
What we know about the dinosaurs and their extinction is limited to fossils and large amounts of rock. Scientists also study evolution to learn more about the Great Extinction.
Dinosaurs developed because of an extinction event.
Detailed studies can be done using radioactive isotopes characteristic of a specific period. By dating rocks, scientists have found out that The Triassic – Jurassic – Cretaceous boundary was formed by an asteroid impact that threw dust and gas into the atmosphere and blocked sunlight for months to years.
Believe it or not, the K–Pg extinction event wasn’t the first mass extinction of life on Earth. Scientists have found that there have been five mass extinctions.
The Ordovician-Silurian extinction occurred about 440 million years ago and was probably caused by a glaciation event (when glaciers cover large land areas).
The late Devonian extinction occurred about 375 million years ago, and scientists think a large drop in sea levels caused it.
The Permian-Triassic extinction event was the one that affected dinosaurs. It occurred about 252 million years ago and killed around 96% of all species.
The Triassic-Jurassic extinction event was about 200 million years ago and may have been caused by an asteroid as well.
Scientists believe that climate change can cause extinction but that it wouldn’t wipe out all life, as an asteroid could.
It appears there’s a new mass extinction event every 100 million years or so – considering the last one was 65 million years ago; I would say we have about 40 million years to prepare for the next one. 🙂
How long exactly did it take for the Earth’s environment to recover from this impact?
It probably took only a few thousand years after the impact until most animals became extinct. But it took millions of years before all traces of the asteroid impact were gone.
How long did it take before the first new life forms emerged?
New species of plants and animals appeared 2-3 million years after the impact, but they were very different from anything that went extinct at this time. These changes to Earth’s environment and climate probably caused evolutionary pressure toward new adaptations, leading to new species. It’s not clear how long exactly it took for evolution to lead to present-day species, but most scientists agree it occurred over millions of years.
What dinosaur is still alive?
Some dinosaurs are still alive. They’re called: Birds! The only known descendants of dinosaurs are birds. Birds evolved from theropod dinosaurs and shared some features with their ancestors, but they also have many unique characteristics that make them completely different from non-avian dinosaurs.
These are some excellent questions about dinosaurs, but we don’t know all the answers yet! Luckily, paleontologists work every day to learn more about these fascinating creatures and their ancestors.