A team excavating a burial cave in Galilee, northern Israel, uncovered the remains of at least 71 tortoises and three wild cattle.
The shells and bones showed evidence of the animals being cooked and butchered for human consumption.
The finds were in two specially crafted hollows linked to burial rituals, said the researchers writing in the journal Proceedings of the National Academy of Sciences.
Tortoise shells were placed under, around and on top of the remains of a ritually buried shaman.
Meat from the tortoises alone could probably have fed around 35 people, according to study leader Dr Natalie Munro, from the University of Connecticut, United States.