https://www.sciencedaily.com/releases/2020/03/200309135410.htm

The new method focused a laser on small bits of shell, making holes 10 micrometers in diameter, or about as wide as a red blood cell. Trace elements in these tiny samples reveal information about the temperature and chemistry of the water at the time the shell formed. The analysis provided accurate measurements of the width and number of daily growth rings as well as seasonal patterns. The researchers used seasonal variations in the fossilized shell to identify years.

 

https://www.sciencedaily.com/releases/2020/03/200309135410.htm

It's amazing just how far science has come. To think that a chronological play-by-play of the Chicxulub impact that wiped out the dinosaurs is a actually a feasible thing in this day and age. Incredible!

 

Even a chronological play-by-play of the Chicxulub impact that wiped out the dinosaurs is a feasible thing in this day and age.

As a matter of fact, the holy grail of this event was discovered a few years ago. Check this article, it's a little long but very much worth your time. I suggest you read it in your PC or laptop, and not your phone.

 

As a matter of fact, the holy grail of this event was discovered a few years ago. Check this article, it's a little long but very much worth your time. I suggest you read it in your PC or laptop, and not your phone.

One thing that is still a little hazy to me is why certain creatures were spared while others were not. Maybe the Earth cooled down so much and the largest ones just had too much difficulty finding shelter? I think we're getting close to some more precise answers about things like that, it's still going to take some time to actually apply these advanced techniques "on the field". New discoveries every day though, it won't be long...

 

Maybe the Earth cooled down so much and the largest ones just had too much difficulty finding shelter?

There was a plethora of factors for that, I'm sure... one of them is that the Earth had more oxygen in its atmosphere back then (about 30% more, if I remember correctly), and this oxygen went down dramatically because the skies lost their transparency for at least a century, and so plant life suffered dramatically, and so oxygen content went down. Most likely, the very large creatures could simply not cope with that change, whilst the small ones had less trouble adapting.