Archaeologists in Israel have unearthed 10 "extremely rare" prehistoric stone hand axes that were crafted to deliberately include geological features, including fossils and geodes, a new study finds.

The hand axes were probably made by Homo erectus between 500,000 and 200,000 years ago, likely because our human ancestors thought these objects were imbued with potency and cosmic significance, the study researchers suggested, although others argue further evidence would benefit the study.

Local resident and study co-author Muataz Shalata discovered several ordinary hand axes in the Sakhnin Valley, Israel, between 2024 and 2025. Following his discovery, Shalata notified Ran Barkai, a professor of archaeology at Tel-Aviv University.

A dedicated survey in 2025 revealed more than 200 hand axes at Sakhnin Valley, including 10 that include fossils, geodes or other geological features, such as hollows that looked like mini-caves and a concretion forming a round ripple-like feature.

These tools are "unique because until now such items were singularly found, only one extraordinary piece here and there," Barkai, the study's first author, told Live Science in an email."

The discovery contributes to a debate regarding whether early humans recognized or consciously noted geological features and fossils, or whether their occurrence in stone tools was merely accidental. However, the new discovery of multiple tools with these features in the same area suggests it was a deliberate act, the researchers said in the study.

Incorporating these fossil-carrying rocks into tools created "true obstacles towards the stone worker and user," Barkai said, because they made the tools more brittle and difficult to shape. Yet, despite these disadvantages, Homo erectus incorporated these features into their hand axes, which suggests it was done deliberately, he said.

Imbued with potency and cosmological significance

The researchers speculate that early humans were drawn to these unusual features and possibly believed they had metaphysical importance. This, the researchers argue, is a behavioral trait seen across cultures and time and even in other primates, suggesting that curiosity about extraordinary objects is an ancient trait. In this case, the researchers "cautiously suggest" that early humans saw these fossils "as traces of a primordial time and place," and ascribed to them a special potency, they wrote in the study.

Once these rocks were crafted into tools, they were mainly used to butcher large animals, including elephants and their extinct relatives, species that were central to early human survival.

This link between elephants and hand axes is supported by the fact that replicas of stone hand axes were sometimes also made from broken elephant bones, suggesting a deeper relationship between humans, elephants and hand axes, according to the study.

When elephant populations began to decline in the Levant (an area in the Eastern Mediterranean) at this time, it likely created a period of great stress, Barkai said. He stated that previous studies have shown that early humans deliberately placed their hand ax production sites along elephant migration routes close to water sources. The researchers called this the "holy triad of elephants, stone and water," suggesting a deep connection between humans and elephants.

The researchers speculated that early humans saw stone not just as a natural resource to be utilized but also as a way to connect with the cosmos. For example, the study found that Homo erectus deliberately shaped a stone ball from a geode — a painstaking process that would have served no practical purpose, suggesting these early hominins likely saw a value beyond the practical in these features.

"Early humans were more and more desperate for the potency of the cosmos to come to their assistance," Barkai said. "I believe that humans were not just manipulating 'natural resources' by using stone tools, but were doing this while paying respect to these entities … thus the stone tools were always conceived as mediators between humans and the cosmos."

Other researchers note that while the findings are significant, more evidence is needed to further support the symbolic inferences. Sarah Wurz, a professor of archaeology at the University of the Witwatersrand in South Africa who was not involved with the study, told Live Science in an email that "these extraordinary hand axe finds are noteworthy and provide new evidence of the perceptive abilities of past humans." However, she added that "further inferential scaffolding [evidence] would strengthen the interpretation of symbolic behavior."

Barkai plans to conduct more excavations that will provide greater insights into these tools and their uses.

"The artifacts that have been retrieved by now are from the surface only," Barkai said. "We plan to conduct excavations at the site in the future, and will surely run these kinds of analyses on items recovered from pristine archaeological context, as we did in the past with very good results."

Sandee Oster is a freelance journalist and Ph.D. candidate based in South Africa. Her beats include archaeology, history and paleontology. Her work has appeared on Phys.org, the Southern African Archaeology Student Society, and she has a popular Medium blog. Her Ph.D. in archaeology is being completed at the University of the Witwatersrand and is focused on developing her zooarchaeological skills, while her master's degree dealt with archaeological rock art.