A granite boulder carved more than 35,000 years ago deep in a cave in Israel may be the oldest evidence of ritual practices in the Holy Land, a new study suggests.
The grooves carved into the boulder look strikingly similar to the pattern of a tortoise shell. While it's unknown what this design means, it's possible that this was an ancient symbol of unification, according to study co-author Israel Hershkovitz, a physical anthropologist at Tel Aviv University.
