Anthropologists have unearthed the remains of an apparent Neanderthal cave sleeping chamber, complete with a hearth and nearby grass beds that might have once been covered with animal fur.
Neanderthals inhabited the cozy Late Pleistocene room, located within Esquilleu Cave in Cantabria, Spain, anywhere between 53,000 to 39,000 years ago, according to a Journal of Archaeological Science paper concerning the discovery.
Living the ultimate clean and literally green lifestyle, the Neanderthals appear to have constructed new beds out of grass every so often, using the old bedding material to help fuel the hearth.
"It is possible that the Neanderthals renewed the bedding each time they visited the cave," lead author Dan Cabanes told Discovery News.
Cabanes, a researcher at the Weizmann Institute of Science's Kimmel Center for Archaeological Research, added that these hearth-side beds also likely served as sitting areas during waking hours for the Neanderthals.
"In some way, they were used to make the area near the hearths more comfortable," he said, mentioning that artifacts collected from various other Neanderthal sites suggest the inhabitants prepared stone tools, cooked, ate and snoozed near warming fires.
For this study, Cabanes and his team collected sediment samples from the Spanish cave. Detailed analysis of the samples allowed the scientists to reconstruct what materials were once present in certain parts of the cave at particular times.
The bedding material was identified based on the presence and arrangement of multiple phytoliths from grasses near the hearth area. Phytoliths are tiny fossilized particles formed of mineral matter by a once-living plant.
There was no evidence of plants growing, soil developing or animal transport of phytoliths via dung, so the scientists believe the only plausible explanation is that Neanderthals gathered the grass and placed it in this room of the cave.
While the hearth contained some grass phytoliths, most belonged to wood and bark, "indicating that this material was the main type of fuel used," according to the researchers. Some animal bones were also tossed into the hearth, perhaps to dispose of them after dinner and/or for use as extra fire fuel.
Evidence is building that Neanderthals in other locations constructed such functional living spaces within caves and rock shelters.
Earlier this year, Josep Vallverdu of the Catalan Institute of Human Paleoecology and Social Evolution and his team identified a "sleeping activity area" at Spain's Abric Romani rock shelter.
Similar to the Esquilleu Cave finds, Vallverdu and his colleagues discovered the remains of hearths spaced enough for seating and sleeping areas.
"This set of combustion activity areas suggests analogy with sleeping and resting activity areas of modern foragers," Vallverdu and his team wrote. They added that such information can allow anthropologists to estimate the size of Neanderthal populations, in addition to learning more about how they lived.
The big question, according to Cabanes, is how such a resourceful species went extinct.
"In my opinion, Neanderthal extinction may have been caused by several factors working at the same time," he said. "Environmental changes, a slightly different social organization, a different rate of reproduction, spread of diseases, direct competition for resources and many other factors may have played an important role in the fate of Neanderthals."
He and other researchers have also not ruled out that Neanderthals were simply absorbed into the modern human population.
Cabanes is hopeful that future analysis of phytoliths, as well as other less obvious clues that have often been overlooked by scientists in the past, may shed additional light on the still-mysterious Neanderthals.