In the rolling landscapes of South Africa’s Cango Valley, the ground hides more than rock and soil. Beneath its limestone hills, narrow passages lead into an ancient underworld — a place where bones have slept for hundreds of thousands of years, waiting to tell their stories. Some may belong to zebras and wildebeests. Others may hold the secrets of our own distant ancestors.
For decades, this fossil-rich region went largely unnoticed. But now, a new wave of exploration is peeling back the layers of time, revealing an underground archive that could transform what we know about early humans and the world they inhabited.
The Search Begins with a Forgotten Report
It started, oddly enough, with an old document from the 1980s. Tyler Faith, a paleoecologist and curator of paleontology at the Natural History Museum of Utah, had come across a brief mention of caves somewhere near the tip of South Africa. The location wasn’t precise — just “in the Cango Valley.” Faith knew the valley was threaded with limestone outcrops, the kind of rock that often hides caves within.
When he arrived in 2022, he quickly realized the problem: there weren’t just a few caves. There were dozens. “We found all these caves, and there appears to be a really rich fossil record within them,” Faith recalled. “Fossils are everywhere.”
Over the next few years, he returned, squeezing through narrow openings, mapping chambers, and documenting two dozen sites. Each cave, it seemed, was a potential treasure chest.
How Bones Find Their Way Underground
The caves themselves are ancient works of water. For millions of years, rain and underground streams gnawed at the limestone, carving tunnels and chambers. Animals entered these caves in many ways — some dragged in by predators, others washed in during floods. And some, in a final misstep, fell through openings and never climbed back out. Over time, layers of sediment entombed their remains, and minerals slowly transformed bone into stone.
Each fossil tells a story not just about an animal, but about the environment it lived in — the climate, the vegetation, the predators and prey. Together, they form an ecological time machine.
Into the Darkness
In June 2025, Faith and his team returned with two goals: find fossils and figure out how old they are. Getting into the caves was the first challenge. The entrances, often hidden beneath trees and thick brush, could be as small as a doorway for a fox. These leafy markers are a subtle clue — caves tend to form where water flows, and water draws vegetation.
Once inside, the team faced a world of sensory extremes. “It’s oppressively quiet and dark,” Faith said. “You start hearing things that aren’t there.” Bat guano coated the floors, alive with squirming cave ticks. Narrow shafts required belly crawling, and some chambers plunged into steep, slippery drops. Without careful mapping, it would be all too easy to get lost.
Discoveries on the Cave Walls and Ceilings
The fossils were not shy about revealing themselves. Bones jutted from walls, ceilings, and the dusty cave floor. The team uncovered remains of ancient wildebeests, zebras, and even carnivores that have yet to be identified. One of the most tantalizing finds was a molar embedded in a cave ceiling, suspiciously similar to a human tooth. Several other hominid-like fragments also surfaced, though it will take further study to confirm whether they belong to our ancient relatives.
Perhaps the most remarkable discovery was a near-complete skeleton of an extinct mountain goat relative, first identified decades ago but never fully described. Until now, only fragmentary remains were known. Faith’s team painstakingly chiseled the specimen free over several days, revealing details that could finally allow scientists to give it a proper name and place it on the evolutionary family tree.
Unlocking the Age of the Fossils
Determining the age of these fossils is no simple task. Faith’s team is focusing on dating the flowstones — sheet-like mineral deposits formed by dripping water — that sandwich the fossil-bearing sediments. These mineral layers act like bookends, providing a minimum and maximum age for whatever lies between them.
Faith suspects the fossils are from the Pleistocene Epoch, a stretch of time from about 2.5 million to 11,700 years ago. More specifically, he thinks many may be older than 100,000 years — a period that is poorly represented in South Africa’s southern fossil record. “If that’s the case,” Faith said, “this could fill a huge gap in our understanding of early humans and the ecosystems they lived in.”
Why It Matters for Human Evolution
Most of South Africa’s older fossils — particularly those related to human evolution — come from sites near Johannesburg, hundreds of miles to the north. The Cango Valley caves could extend that record southward, providing a new window into how ancient humans and other species adapted to changing climates, shifting landscapes, and competition for survival.
If confirmed, the hominid fossils from these caves could help answer questions about migration, adaptation, and even the possible overlap between different human species.
A Future Full of Discoveries
For now, the four caves explored in June are just a beginning. The valley is dotted with “zillions of caves,” as Faith puts it, many of which have never been studied. Each could hold a new species, a new clue, or a new chapter in the story of life on Earth.
“This is work for decades, maybe lifetimes,” Faith said. “Every cave is a time capsule. We’ve only just started opening them.”