I just saw an image of a gecko stuck in amber 58 million years ago. Why don't animals rot when they are trapped in amber? I've seen dry insects whose chitin shells persist for a long time away from water and scavengers, but things with skin rot and dramatically change in appearance in the outside world.

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    $\begingroup$ I am no expert but conifer pitch/sap has a number of compounds that have anti bacterial and anti fungal properties. Tie that together with the anaerobic conditions being encased in pitch would create and it is not too surprising that they are partially preserved. I would wonder if the pitch might also have desiccant type properties as well. $\endgroup$
    – user824
    Jun 7, 2018 at 23:32
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    $\begingroup$ I'm perplexed regarding the onslaught of votes to close for being off-topic. There are several unclosed questions at this site regarding fossils, and a few regarding amber. Just because a question might be on-topic in another corner of the SE universe does not mean it is off-topic here. $\endgroup$ Jun 8, 2018 at 16:47
  • $\begingroup$ I am curious as to what stack people think this belongs on if not earth science? $\endgroup$
    – John
    Mar 25, 2021 at 1:47
  • $\begingroup$ @John maybe biology!?!?? But I'm voting to reopen, for whatever it's worth now, as such questions that can't find a home seem worthwhile if somewhat on topic here, it's not like we're drowning in questions. And if there's somewhere else to move it, it can be discussed. $\endgroup$ Mar 31, 2021 at 16:24
  • $\begingroup$ What if they rot? Rotting produces a lot of poisonous things and that kills the bacteria. If it is hermetically sealed, nothing rots away completely. For example, surströmming (en.wikipedia.org/wiki/Surstr%C3%B6mming) is a fish conserved without any salt or so. It becomes the most stinky food of the world, but it remains eatable. $\endgroup$
    – peterh
    Apr 5, 2021 at 8:08

1 Answer 1


things need to be exposed to bacteria to rot, amber produces a perfect form fitting seal and has several antimicrobial properties to boot killing off bacteria that is already present. Even microbes trapped in amber become preserved. This makes a lot of sense when you realize the resin evolved to seal injuries in trees if it did not prevent the spread of bacteria it would not work. HOwever preservation in amber is not perfect and the things do degrade, but do so so slowly that more geologically recently deposits have decayed so little is is almost undetectable, the type of resin also matters all resin is not equal and some amber resins preserves better than others.


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