Neanderthals are thought to have roamed the Earth for around 360,000 years, during which time the planet experienced several glacial cycles. And while our ancient relatives may have become extinct some 40,000 years ago, new research reveals that they didn’t go down without a fight, and upped their tool game whenever they noticed their world freezing over.

A new study in the journal PLOS One presents a detailed analysis of Neanderthal tools recovered from the Sesselfelsgrotte cave in Lower Bavaria, which has yielded more than 100,000 artifacts and is considered one of the most important Neanderthal sites in central Europe. Using 3D scanning techniques, the researchers were able to observe these ancient utensils in unprecedented detail, noting that they came in numerous shapes and sizes.

This variation in tool design offers new insights into the complexity of Neanderthal survival strategies, as it is generally believed that these extinct hominins relied mostly on single-bladed stone knives known as Keilmesser. However, many of the tools found at Sesselfelsgrotte contained multiple blades, with several edges having been sharpened in order to maximize the cutting surface.

Interpreting this finding, the study authors suggest that these more complex knives became fashionable at a time when global temperatures plummeted around 60,000 years ago. As ice spread across the land, Neanderthals found they had less access to vital resources and were therefore forced to adopt a more nomadic lifestyle.

This necessitated the development of longer-lasting tools that could be relied on during long journeys without having to be replaced as regularly as the older single-sided knives. In a statement, study author Thorsten Uthmeier said that the development of bifacially-shaped knives during this period “is not only direct proof of the advanced planning skills of our extinct relatives, but also a strategical reaction to the restrictions imposed upon them by adverse natural conditions.”

By extension, Uthmeier asserts that Neanderthals were capable of developing technological solutions to changing environmental pressures, which tells us something about their adaptability.

“Unlike some people have claimed, the disappearance of the Neanderthals cannot have been a result of a lack of innovation or methodical thinking,” he says.