This may be better asked as two questions; if so, I will edit.

The question is prompted by a section in Neanderthal Man: In Search of Lost Genomes by Svante Pääbo, who was the first to sequence Neanderthal (and Denisovan) DNA. Pääbo and his team had to work out techniques for sequencing nuclear DNA ten and more thousands of years old. They experimented with coprolites -- fossilized feces -- of the extinct American ground sloth.

The giant sloths had left behind large amounts of droppings, which archaeologists dressed up with the fancy name of coprolites. In fact, in some caves in places like Nevada, the entire floor, to some depth, is largely made up of old ground-sloth feces.

So, suppose one has to take shelter in a cave in Nevada: how would one distinguish an ordinary dirt floor from a floor formed of coprolites of the extinct American ground sloth? Are there any risks involved in taking shelter in any of the coprolite caves? (except for the possible ick factor)

[This sloth,] Mylodon, weighed about 1,000 kilograms (2,205 lb)[2] and was about 3 m (9.8 ft) long from snout to tail tip

  • 4
    You are aware that every time you walk across a grassy lawn, that it is composed of a very high amount of worm castings, right? And should we talk about what honey is?
    – cobaltduck
    Commented May 18, 2017 at 17:40
  • @cobaltduck Yes, as a gardener, I know what worm castings are. I still would like to know how, if at all, a coprolite floor from a 1,000 kg ground sloth differs from a (more) ordinary dirt floor.
    – ab2
    Commented May 18, 2017 at 18:23

1 Answer 1


No, there are no risks, assuming you're asking abput biohazards. This is poop so old it has petrified, become stone and/or sand. The only microorganisms that actively live in there are ones that can also live in other types of sand. There are some forms of bacterial and probably fungal spores that can stay alive in a suspended state for tens or even hudreds of millions of years, but since this is a cave floor made of crumbling poop rather than some well preserved ancient crystal and you stomp around in it rather than creating the perfect conditions for these bacteria to come back to life I figure you're quite safe. Also because the main poop bacteria that make people sick, like E. Coli, don't form spores at all.

Unless you're worried about disturbing an important feces research site, you'll be fine.

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