Humans were organising mass banquets to foster community spirit 12,000 years ago, scientists learned.
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.
"This is the first solid evidence that supports the idea that communal feasts were already occurring - perhaps with some frequency - at the beginnings of the transition to agriculture," she said.
"We don't know exactly how many people attended this particular feast, or what the average attendance was at similar events, since we don't know how much meat was actually available in the cave. The best we can do is give a minimum estimate based on the bones that are present."
Feasts served as community builders at a time of rising social tension, said Dr Munro.
Population was growing and people turning from nomadic to more settled ways of living, causing the landscape to become crowded.
"People were coming into contact with each other a lot, and that can create friction," she said. "Before, they could get up and leave when they had problems with the neighbours. Now, these public events served as community-building opportunities, which helped to relieve tensions and solidify social relationships.
"The appearance of these feasts at the beginnings of agriculture is particularly interesting because people are starting to experiment with domestication and cultivation."