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I don't know why your comment has gotten downvoted so much. Astroid impact proponents present their view as rock solid but the reality is there are holes in th

by vivekd 5y ago

I don't know why your comment has gotten downvoted so much. Astroid impact proponents present their view as rock solid but the reality is there are holes in the evidence (like population decline prior to impact) and credible alternative theories like massive volcanic activity. The entire field of palentology seems like an acrimonous mess. https://www.theatlantic.com/magazine/archive/2018/09/dinosaur-extinction-debate/565769/ https://www.theatlantic.com/magazine/archive/2018/09/dinosau...

EdwardDiego 5y ago
Why not both asteroids and the Deccan Traps? Given it was spewing out massive amount of gases for millions of years prior to the Yucatan impact, I don't see any conflict between the population declines prior and the Yucatan impact finishing it off.
- dredmorbius 5y ago
  Or the impact itself amplifying the erruption(s) and impacts. The seismic ground shock would have been felt around the world. At the antipodes, depending on the model chosen, there might have been from 4--30m of vertical displacement. http://www.geologyinmotion.com/2011/10/chicxulub-impact-what-happened-on.html http://www.geologyinmotion.com/2011/10/chicxulub-impact-what... AFAIU, this would have been nearer Australia than India, though I'm not certain, and the Indian plate and Deccan Traps could plausibly have been within or near the enhanced antipodal seismic zone.
eesmith 5y ago
There is no real doubt that the Chicxulub bolide impact occurred, caused shockwaves and tsunamis, and ejected a bunch of hot material. Eg, quoting https://www.pnas.org/content/pnas/116/17/8190.full.pdf https://www.pnas.org/content/pnas/116/17/8190.full.pdf, "The KPg boundary ... is distinguished by impact-related debris, including a distinctive iridium anomaly, shocked minerals, ejecta spherules, microkrystites, nanodiamonds, and occasionally unaltered impact-melt glass." (That paper is about the amazing Tanis site, where a ∼1.3-m-thick deposit records events which occurred minutes to hours after the impact, and includes pterosaur fossils and perhaps dinosaur feathers and a hip bone. https://en.wikipedia.org/wiki/Tanis_(fossil_site) https://en.wikipedia.org/wiki/Tanis_(fossil_site) ) Even if non-avian dinosaurs were killed off earlier by consequences of the Deccan traps, we know modern snakes survived, so their ancestors must have survived the Chicxulub impact.
sgt 5y ago
Both - or a combination of even more incidents could be plausible. I guess it would be similar to a disastrous plane accident; usually it's not caused by a single failure, but a multitude of failures with a resulting cascade effect.
zamfi 5y ago
> Astroid impact proponents present their view as rock solid but the reality is there are holes in the evidence […] I…really thought this was going to be a joke post based on this sentence!
Sebb767 5y ago
> I don't know why your comment has gotten downvoted so much. I did not downvote (I try to assume best intent), but to me the tone of the comment reads more like "make sure everyone falls for the first lie" rather than "this theory is not yet totally proven". The phrase "(make) everyone believe" is just to overused by conspiracy theorists these days and 'prove' or 'find more evidence' would fit much better for a scientific discussion.
- SturgeonsLaw 5y ago
  Q told me the Democrats wiped out the dinosaurs
  - spockz 5y ago
    What do the Q have to do with this?
  - bregma 5y ago
    Meteor impacts can't melt steel beams. Bush did Chucxulub.
himinlomax 5y ago
There is no contradiction: from a systems point of view, a single event may not have been enough to have such a massive impact. The fact is, we're not seeing a single non avian dinosaur in the fossil record after the event. Same for entire other genuses. If the system hadn't already been destabilized beforehand, we probably would have seen remnants lingering for a couple million years or more. Instead, we see a crystal clear cut off date.
pfdietz 5y ago
The extinction occurred exactly at the impact boundary. If you are denying a casual link then you are proposing an extreme coincidence. The link you give is to a story about a notorious gadfly. She has not convinced the field, far from it. I get the impression there is little patience for the reasoning she has presented in her papers on the subject.

by vivekd 5y ago

EdwardDiego 5y ago

Why not both asteroids and the Deccan Traps? Given it was spewing out massive amount of gases for millions of years prior to the Yucatan impact, I don't see any conflict between the population declines prior and the Yucatan impact finishing it off.

dredmorbius 5y ago
Or the impact itself amplifying the erruption(s) and impacts. The seismic ground shock would have been felt around the world. At the antipodes, depending on the model chosen, there might have been from 4--30m of vertical displacement. http://www.geologyinmotion.com/2011/10/chicxulub-impact-what-happened-on.html http://www.geologyinmotion.com/2011/10/chicxulub-impact-what... AFAIU, this would have been nearer Australia than India, though I'm not certain, and the Indian plate and Deccan Traps could plausibly have been within or near the enhanced antipodal seismic zone.

eesmith 5y ago

There is no real doubt that the Chicxulub bolide impact occurred, caused shockwaves and tsunamis, and ejected a bunch of hot material. Eg, quoting https://www.pnas.org/content/pnas/116/17/8190.full.pdf https://www.pnas.org/content/pnas/116/17/8190.full.pdf, "The KPg boundary ... is distinguished by impact-related debris, including a distinctive iridium anomaly, shocked minerals, ejecta spherules, microkrystites, nanodiamonds, and occasionally unaltered impact-melt glass." (That paper is about the amazing Tanis site, where a ∼1.3-m-thick deposit records events which occurred minutes to hours after the impact, and includes pterosaur fossils and perhaps dinosaur feathers and a hip bone. https://en.wikipedia.org/wiki/Tanis_(fossil_site) https://en.wikipedia.org/wiki/Tanis_(fossil_site) ) Even if non-avian dinosaurs were killed off earlier by consequences of the Deccan traps, we know modern snakes survived, so their ancestors must have survived the Chicxulub impact.

sgt 5y ago

Both - or a combination of even more incidents could be plausible. I guess it would be similar to a disastrous plane accident; usually it's not caused by a single failure, but a multitude of failures with a resulting cascade effect.

zamfi 5y ago

> Astroid impact proponents present their view as rock solid but the reality is there are holes in the evidence […] I…really thought this was going to be a joke post based on this sentence!

Sebb767 5y ago

> I don't know why your comment has gotten downvoted so much. I did not downvote (I try to assume best intent), but to me the tone of the comment reads more like "make sure everyone falls for the first lie" rather than "this theory is not yet totally proven". The phrase "(make) everyone believe" is just to overused by conspiracy theorists these days and 'prove' or 'find more evidence' would fit much better for a scientific discussion.

SturgeonsLaw 5y ago
Q told me the Democrats wiped out the dinosaurs
- spockz 5y ago
  What do the Q have to do with this?
- bregma 5y ago
  Meteor impacts can't melt steel beams. Bush did Chucxulub.

himinlomax 5y ago

There is no contradiction: from a systems point of view, a single event may not have been enough to have such a massive impact. The fact is, we're not seeing a single non avian dinosaur in the fossil record after the event. Same for entire other genuses. If the system hadn't already been destabilized beforehand, we probably would have seen remnants lingering for a couple million years or more. Instead, we see a crystal clear cut off date.

pfdietz 5y ago

The extinction occurred exactly at the impact boundary. If you are denying a casual link then you are proposing an extreme coincidence. The link you give is to a story about a notorious gadfly. She has not convinced the field, far from it. I get the impression there is little patience for the reasoning she has presented in her papers on the subject.