Human Coprolites: What Ancient Poop Reveals

PALEODEX · 8 August 2026 · 5 min read

It's not just dinosaurs. Every human culture has left the same kind of fossil behind — and two finds from opposite ends of history show exactly why that matters.

We've written before about coprolites as a trace-fossil record of animal behavior. Humans are animals too, and it turns out we've been leaving the same kind of evidence for as long as we've existed — sometimes with much higher stakes than a dinosaur's dinner.

The oldest Americans, found in poop

In 2008, a team led by geneticist Eske Willerslev announced a striking result: human mitochondrial DNA recovered from coprolites at Paisley Caves, a dry rockshelter site in south-central Oregon. The coprolites were directly radiocarbon-dated to roughly 14,300 years old — centuries before the Clovis culture, long treated as the first well-documented human presence in the Americas. The DNA lineages matched populations from Siberia and East Asia, consistent with the ancestors of the first Americans.

It's a good example of why we try to show what's disputed here, not just what's exciting. The claim was immediately challenged: a 2009 comment published in the same journal, Science, questioned whether every sample was genuinely human — one contained plant material more consistent with an herbivore's diet — and raised concerns about contamination and dating reliability. Archaeologist Dennis Jenkins and colleagues went back with stricter protocols specifically designed to rule out modern contamination, and the pre-Clovis dates held. The debate over some details continues, which is exactly the point: a handful of fossilized droppings forced a real argument about who got to the Americas first, and when.

A Viking's very bad day

Not every coprolite has to solve a continental mystery to be worth digging up. In 1972, archaeologists excavating the Viking-age settlement of Jórvík — now the English city of York — for the site of a new Lloyds Bank branch found a single spectacular specimen: a fossilized human stool about 20 centimeters long, dated to the 9th century. Analyzed by archaeologist A. K. G. Jones in 1983, it remains one of the largest human coprolites ever recovered.

The analysis found a diet heavy in meat and bread — a narrower menu than other Jórvík residents, whose remains show traces of fruit, shellfish, and nuts. It also contained the eggs of several hundred intestinal parasites, mostly whipworm and maw-worm, both common at the time. The "Lloyds Bank coprolite" is now on permanent display at the Jorvik Viking Centre, close to where it was found.

What poop tells us that bones can't — again

The pattern matches every other coprolite on this site: it's evidence of behavior, not anatomy. Human coprolites can preserve pollen (revealing the season a meal was eaten), plant and animal remains (revealing diet in detail), parasite eggs (revealing disease burden), and — in exceptional, carefully-verified cases — degraded ancient DNA. None of that survives in a skeleton.

Why this is exactly what we built PaleoDex for

This is the same unglamorous, rigorously-sourced science the whole app is built on: real specimens, real disagreements, no invented certainty either way. The famous finds get the headlines; a Viking's leftover lunch and a contested cave in Oregon quietly rewrite what we know about the deep human past. Browse the wider fossil record in the Fossil-DEX, or read more on what coprolites are and how they form.

Sources

A disputed cave and a Viking's bad day — sources below.

• DNA from Pre-Clovis Human Coprolites in Oregon, North America — Gilbert et al., Science (2008)
• Comment on "DNA from pre-Clovis human coprolites in Oregon, North America" — Science (2009)
• Lloyds Bank coprolite — background and Jones (1983) analysis