3 ms·

My understanding is that it may have finished them off quite decidedly, at least those that were not on their way to becoming birds & others, but evidence sugge

My understanding is that it may have finished them off quite decidedly, at least those that were not on their way to becoming birds & others, but evidence suggests many of the large species were already in significant decline due to other pressures (there are various theories about what the main cause(s) of that was, including changes in atmosphere balance, changes in temperature, changes in food supply due to evolution elsewhere in the chain, etc.)

Robotbeat 6y ago
I recently did a review of just what happened during the asteroid/comet impact and afterward, and it was insanely bad. And not limited to near the impact site, either, as ejecta shot back into space and rained down on the whole planet. The atmospheric temperature was well above boiling, rain of fiery stones starting literally all the world’s forests on fire, earthquakes of 11 on the Richter scale. For those within visual distance of the impactor, flesh would turn to flame due to the intensity of the light. Massive inland tsunamis. Followed by years and decades of dark winter (50 degrees below average) and then 5 deg C global warming for thousands of years. Almost everything would’ve been dead on land within hours. That species survived means a few individuals survived. Something like 99% of everything living on land would’ve been killed early on. No exclusively land-based tetrapods over 25 kilograms survived.
- tolbish 6y ago
  I would like to learn more about these 11-on-the-Richter-scale earthquakes.
  - Robotbeat 6y ago
    Here’s a dramatization of the Earthquakes (etc) from when the impactor hit: https://youtu.be/vq3nWnTkFbk https://youtu.be/vq3nWnTkFbk
    - tolbish 6y ago
      Thank you for the link. I haven't felt this bad for dinosaurs since the death of Littlefoot's mother.
hownottowrite 6y ago
Look at the data around the late Cretaceous Deccan Traps eruptions. It's pretty clear that large scale volcanic activity is the real culprit, just as it's been with nearly every mass extinction event. The impact event had a big effect too but the end was already written before the cosmic gun went off. There's also emerging evidence that dinosaurs survived in pockets for a few hundred thousand years after the impact. Most of this comes out of New Mexico and is based on radiometric sequences that have yet to be accepted on a wide scale, but it is there.

Robotbeat 6y ago

I recently did a review of just what happened during the asteroid/comet impact and afterward, and it was insanely bad. And not limited to near the impact site, either, as ejecta shot back into space and rained down on the whole planet. The atmospheric temperature was well above boiling, rain of fiery stones starting literally all the world’s forests on fire, earthquakes of 11 on the Richter scale. For those within visual distance of the impactor, flesh would turn to flame due to the intensity of the light. Massive inland tsunamis. Followed by years and decades of dark winter (50 degrees below average) and then 5 deg C global warming for thousands of years. Almost everything would’ve been dead on land within hours. That species survived means a few individuals survived. Something like 99% of everything living on land would’ve been killed early on. No exclusively land-based tetrapods over 25 kilograms survived.

tolbish 6y ago
I would like to learn more about these 11-on-the-Richter-scale earthquakes.
- Robotbeat 6y ago
  Here’s a dramatization of the Earthquakes (etc) from when the impactor hit: https://youtu.be/vq3nWnTkFbk https://youtu.be/vq3nWnTkFbk
  - tolbish 6y ago
    Thank you for the link. I haven't felt this bad for dinosaurs since the death of Littlefoot's mother.

hownottowrite 6y ago

Look at the data around the late Cretaceous Deccan Traps eruptions. It's pretty clear that large scale volcanic activity is the real culprit, just as it's been with nearly every mass extinction event. The impact event had a big effect too but the end was already written before the cosmic gun went off. There's also emerging evidence that dinosaurs survived in pockets for a few hundred thousand years after the impact. Most of this comes out of New Mexico and is based on radiometric sequences that have yet to be accepted on a wide scale, but it is there.