<p>No, there is no massive difference in fossil quality due to the extra 200 million years or so that the oldest dinosaur fossils have spent in the ground compared to the most recent ones at the end of the Cretaceous. Once fossils are properly fossilised, they remain unchanged unless something happens to the rocks. This could be weathering, which damages or destroys many valuable fossils, including recent ones like hominids, or it could be metamorphism, which damages or destroys them with heat.</p>

<p>I have seen a photo of a one-billion-year-old fossil from the late Precambrian of a marine algae reliably dated by the new Rhenium 187 - Osmium 187 method, and it was in an excellent state of preservation. Likewise with fossils preserved in amber, some of which are tens of millions of years old but look as fresh as if they had only died yesterday.</p>

CC BY-SA 4.0
2020-02-24T02:33:01.430Z
I'm not sure what's wrong with this answer. Although this user often writes really bad answers, this one is pretty much correct. Upvoted.
Gimelist
CC BY-SA 4.0
2020-02-24T08:10:54.030Z
For an example of amber fossilisation, see "What features facilitate amber fossilisation" a couple of questions further on.
Michael Walsby
CC BY-SA 4.0
2020-07-23T03:42:04.503Z
there is however a drop off in quantity, just due to having more chances to get damaged or destroyed.
John
CC BY-SA 4.0
2020-02-23T19:19:31.587Z
2020-02-23T19:19:31.587Z
Michael Walsby
<p>This proably cannot be answered in a scientifically valid way at this time. There are hundreds of thousands of fossils across that span of time and no one has looked at all of them, &quot;quality&quot; is not something that is measured routinely. Worse there is a massive confounding factor, different formations have drastically different preservational quality. For instance the Solnhafen is a much earlier formation than the Lance formation but has drastically better preservation amd detail just becasue of the drastically different environments.</p>
<p>Even trying to study this question would be swamped with problems just due to how drastically different the quantity of fossils are from each time period. Quality for fossils is strongly influenced by the local formation conditions (chemistry, grain size, burial speed, ect.) so it may be nearly impossible to answer without doing a specific study( it would be very expensive study). I am aware of no such study ever having been done and I know of no generally recognized difference but this is just one paleontologists experience.</p>

CC BY-SA 4.0
2020-07-23T23:35:09.997Z
2020-07-26T23:12:17.753Z
2020-07-26T23:12:17.753Z
John
<p>One thing that still blows my mind about dinosaurs is the massive timeline.  Relevant to this question are <a href="https://www.activewild.com/dinosaur-periods/" rel="nofollow noreferrer">the time periods</a>:</p>

<ul>
<li>Triassic Period (252.17 to 201.3 million years ago)</li>
<li>Cretaceous Period (145 – 66 million years ago)</li>
</ul>

<p>Triassic-period dinosaur fossils are 50+ million years older than Cretaceous-period dinosaur fossils.  I would thus predict a massive difference in fossil quality.  However, I'm unsure because perhaps any fossil that's able to last say 1 million years can just as easily last say 100 million years.</p>

<p><strong>Question</strong>: Is there a massive drop in quality of Cretaceous vs. Triassic dinosaur fossils?</p>

CC BY-SA 4.0
2020-07-23T23:20:32.187Z
This is going to be a very opinion based answer, there are hundreds of thousands of fossils across that span of time and no one has looked at all of them, "quality" is already an opinion laden word.
John
<paleontology><fossils>
Is there a massive drop in quality of Cretaceous vs. Triassic dinosaur fossils?
Rebecca J. Stones
# Is there a massive drop in quality of Cretaceous vs. Triassic dinosaur fossils?

(Asked by: username_0 on 2020-02-23)

One thing that still blows my mind about dinosaurs is the massive timeline. Relevant to this question are [the time periods](https://www.activewild.com/dinosaur-periods/):

* Triassic Period (252.17 to 201.3 million years ago)
* Cretaceous Period (145 – 66 million years ago)

Triassic-period dinosaur fossils are 50+ million years older than Cretaceous-period dinosaur fossils. I would thus predict a massive difference in fossil quality. However, I'm unsure because perhaps any fossil that's able to last say 1 million years can just as easily last say 100 million years.

**Question**: Is there a massive drop in quality of Cretaceous vs. Triassic dinosaur fossils?

**Tags:** paleontology, fossils

> **Comments:**
> **username_1**: This is going to be a very opinion based answer, there are hundreds of thousands of fossils across that span of time and no one has looked at all of them, "quality" is already an opinion laden word.  

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## 2 answers

### Answer by username_2 on 2020-02-23. Score: 1

No, there is no massive difference in fossil quality due to the extra 200 million years or so that the oldest dinosaur fossils have spent in the ground compared to the most recent ones at the end of the Cretaceous. Once fossils are properly fossilised, they remain unchanged unless something happens to the rocks. This could be weathering, which damages or destroys many valuable fossils, including recent ones like hominids, or it could be metamorphism, which damages or destroys them with heat.

I have seen a photo of a one-billion-year-old fossil from the late Precambrian of a marine algae reliably dated by the new Rhenium 187 - Osmium 187 method, and it was in an excellent state of preservation. Likewise with fossils preserved in amber, some of which are tens of millions of years old but look as fresh as if they had only died yesterday.

> **Comments:**
> **username_3**: I'm not sure what's wrong with this answer. Although this user often writes really bad answers, this one is pretty much correct. Upvoted.  
> **username_2**: For an example of amber fossilisation, see "What features facilitate amber fossilisation" a couple of questions further on.  
> **username_1**: there is however a drop off in quantity, just due to having more chances to get damaged or destroyed.  

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### Answer by username_1 on 2020-07-23. Score: 0

This proably cannot be answered in a scientifically valid way at this time. There are hundreds of thousands of fossils across that span of time and no one has looked at all of them, "quality" is not something that is measured routinely. Worse there is a massive confounding factor, different formations have drastically different preservational quality. For instance the Solnhafen is a much earlier formation than the Lance formation but has drastically better preservation amd detail just becasue of the drastically different environments.

Even trying to study this question would be swamped with problems just due to how drastically different the quantity of fossils are from each time period. Quality for fossils is strongly influenced by the local formation conditions (chemistry, grain size, burial speed, ect.) so it may be nearly impossible to answer without doing a specific study( it would be very expensive study). I am aware of no such study ever having been done and I know of no generally recognized difference but this is just one paleontologists experience.


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