Naked Science Forum

Non Life Sciences => Geology, Palaeontology & Archaeology => Topic started by: OokieWonderslug on 18/10/2020 03:02:40

Title: Why no k/t fossils?
Post by: OokieWonderslug on 18/10/2020 03:02:40
World wide we have the layers made my the meteor that wiped out the dinosaurs. But to the best of my knowledge they've never found a dinosaur fossil IN that layer. If that's what killed them all you'd suspect there would be millions of them everywhere.  Why aren't they?
Title: Re: Why no k/t fossils?
Post by: Kryptid on 18/10/2020 04:36:34
Fossil formation is very rare. Millions of dead bodies does not equal millions of fossilized skeletons. The period of time over which the dinosaurs went extinct after the Chixculub impact is extremely tiny when compared to the many millions of years that dinosaurs lived on Earth. The total number of animals that lived and died during those millions of years would thus be significantly larger than the total number that died after the impact, resulting in far more fossils below the the K-Pg boundary than in it.
Title: Re: Why no k/t fossils?
Post by: Bored chemist on 18/10/2020 12:15:43
World wide we have the layers made my the meteor that wiped out the dinosaurs. But to the best of my knowledge they've never found a dinosaur fossil IN that layer. If that's what killed them all you'd suspect there would be millions of them everywhere.  Why aren't they?
Sreiously?
They would not fit.

https://slate.com/technology/2014/04/the-k-pg-boundary-layer-of-rock-shows-how-the-dinosaurs-died.html
Title: Re: Why no k/t fossils?
Post by: OokieWonderslug on 18/10/2020 16:50:11
Since that layer is preserved world wide the chances of finding a fossil of something covered by that layer should be pretty good. Since I wrote the question it has come to me. Acid rain. The rock blasted by the impact had a high sulfur content. That sulfur came back down as acid rain and that must have dissolved all the dead things that would have been either under or on top of that layer. Either that or the dinosaurs were already mostly gone before the impact. And that the very few that died off just over the layer were in small enough numbers that there just weren't anything left to fossilize. Am I getting warm?
Title: Re: Why no k/t fossils?
Post by: Kryptid on 18/10/2020 17:51:43
Acid rain isn't even as acidic as lemon juice (well, contemporary acid rain anyway). I doubt it would have any significant impact on skeleton degradation. Skeletons usually degrade pretty well on their own. There are animals that eat bones as well.
Title: Re: Why no k/t fossils?
Post by: evan_au on 18/10/2020 20:41:57
That grey layer is a fossil. It is the preserved dust from the meteorite impact.
- It also preserves microspheres which are the result of vaporized rock and dust from the impact re-entering Earth's atmosphere
- Some estimates have suggested that this would have raised the temperature at the surface of the Earth to pizza-oven temperatures for a few hours, worldwide.
- Any dinosaurs caught on the surface would have been burnt to a crisp.

See: https://en.wikipedia.org/wiki/Iridium_anomaly