In Grotta della Basura, a deep cave near Toirano in northern Italy, a team of archaeologists has made a surprising discovery: several handprints and human footprints on the clay floor of the cave, evidence that a small group and heterogeneous of Paleolithic people explored the cave 14,000 years ago.
In the Grotta della Basura, a preliminary study of the fossil traces in glossy leaves is made as a reference for more detailed badyzes. Image credit: Isabella Salvador.
"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 his colleagues studied 180 clues within Grotta della Garra, including fingerprints and footprints on the clay-rich soil.
The scientists applied several dating methods, software that badyzes the structure of the tracks and different types of 3D modeling.
"Together, these approaches allowed us to build a narrative of how humans entered and left the cave, and their activities once they were inside," said Dr. Romano.
Planimetry of the Grotta della Garra and location of human tracks, bears and canids: white rectangles enclose the reconstructions in 3D, obtained by means of a laser scanner, of the innermost room (& # 39; Sala dei Misteri & – left) and the main gallery (& # 39; Corridoio delle impronte & # 39; – right) of the cave, where human traces are preserved; The 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; the blue rectangle indicates 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 discovered that five people, including two adults, a teenager about 11 years old and two children between three and six years old, went barefoot into the cave and illuminated the path with wooden sticks.
This suggests that very young children were active members of Upper Palaeolithic populations, even in seemingly dangerous and social activities.
The researchers also found evidence that they crawled on footprints from a low tunnel, a route that was taken to access the inside of the cave.
The anatomical details on the tracks suggest that the explorers went barefoot while navigating this road.
When badyzing the various handprints, the team found that some of them seem unintentional and relate only to exploring the cave, while others are more intentional and suggest that social or symbolic activities took place within the internal chambers.
"Therefore, hunter-gatherers may have been motivated by fun activities during the exploration, as well as simply by the need to find food," said Dr. Romano.
"Together, our results show how a varied approach to studying the traces of our ancestors can provide detailed information about their behavior," said Dr. Marco Avanzini, head of the department of geology at MUSE – Trento Museum of Science, Italy.
"We hope our approach is useful for painting similar images of how humans behaved in other parts of the world and for different periods of time."
The results were published online this week in the journal. eLife.
Marco Romano et al. 2019. A multidisciplinary approach to a unique paleolithic human ichnological registry of Italy (Cueva Bàsura). eLife 8: e45204; Doi: 10.7554 / eLife.45204