Is that Neanderthal poop on my shoe? Researchers have discovered what is thought to be the world's oldest human poop. The ancient excrement was deposited by Neanderthals some 50,000 years ago in a campsite in Spain. The tested samples showed traces of meats and plants, and proves that early humans were omnivores. Scientists discovered the samples after testing a campfire site, looking for lipids from cooking. "I don't think they were using (the site as a toilet) when the fire was active," one said.