In Grotta della Basura, a deep cave near Toirano in northern Italy, a team of archaeologists has made a surprising discovery: a number of human hand- and footprints on the clay-rich floor of the cave — evidence that a small and heterogeneous group of Paleolithic people explored the cave 14,000 years ago.
“In our study, we wanted to see how ancient humans explored this fascinating cave system,” said Dr. Marco Romano, a postdoctoral researcher at the University of the Witwatersrand, South Africa.
“Specifically, we set out to discover how many people entered the cave, whether they explored as individuals or as a group, their age, gender and what kind of route they took once inside the cave.”
To answer these questions, Dr. Romano and colleagues studied 180 tracks from within Grotta della Basura, including hand and footprints on the clay-rich floor.
The scientists applied various dating methods, software that analyses the structure of the tracks, and different types of 3D modeling.
“Together, these approaches allowed us to construct a narrative of how the humans entered and exited the cave, and their activities once they were inside,” Dr. Romano said.
Planimetry of the Grotta della Basura and location of human, bear and canid footprints: white rectangles enclose the 3D reconstructions, obtained via laser scanner, of the innermost room (‘Sala dei Misteri’ — left) and the main gallery (‘Corridoio delle impronte’ — right) of the cave, where the human footprints are preserved; cross-sections obtained from the 3D reconstruction of the main gallery are highlighted in red and show the branching of the ‘lower’ and ‘upper’ corridors, respectively; blue rectangle indicate the four areas within the main gallery where most of the human footprints are concentrated (A and B for the lower corridor, C and D for the upper corridor). Image credit: Romano et al, doi: 10.7554/eLife.45204.
The team found that five individuals — including two adults, an adolescent of about 11 years old, and two children of three and six years old — entered the cave barefoot and illuminated the way using wooden sticks.
This suggests that very young children were active members of the Upper Paleolithic populations, even in apparently dangerous and social activities.
The researchers also found evidence of crawling in footprints from a low tunnel — a route that was taken to access the inner part of the cave.
Anatomical details in the footprints suggest that the explorers went bare-legged as they navigated this pathway.
When analyzing the various handprints, the team found that some of them appear unintentional and relate to exploring the cave only, while others are more intentional and suggest that social or symbolic activities took place within the inner chambers.
“Hunter-gatherers may therefore have been driven by fun activities during exploration, as well as simply the need to find food,” Dr. Romano said.
“Together, our results show how a varied approach to studying our ancestors’ tracks can provide detailed insights on their behavior,” said Dr. Marco Avanzini, head of the geology department at MUSE — Trento Museum of Science, Italy.
“We hope our approach will be useful for painting similar pictures of how humans behaved in other parts of the world and during different periods of time.”
The results were published online this week in the journal eLife.
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Marco Romano et al. 2019. A multidisciplinary approach to a unique Palaeolithic human ichnological record from Italy (Bàsura Cave). eLife 8: e45204; doi: 10.7554/eLife.45204