Archaeologists have been trying to figure out what happened to the Maya for 100 years - after Mayan cities were mysteriously depopulated in the ninth century.
One theory was that a series of droughts occurred in the Yucatan Peninsula of southeastern Mexico and northern Central America.
But new analysis by researchers by University of California, Riverside archaeologist Scott Fedick and plant physiologist Louis Santiago shows the Maya had nearly 500 edible plants available to them, many of which are highly drought resistant.
Santiago said: "Even in the most extreme drought situation — and we have no clear evidence the most extreme situation ever occurred — 59 species of edible plants would still have persisted."
Some of the toughest plants the Maya would have turned to include cassava with its edible tubers, and hearts of palm.
Another is chaya, a shrub domesticated by the Maya and eaten today by their descendants. Its leaves are high in protein, iron, potassium, and calcium.
"Chaya and cassava together would have provided a huge amount of carbohydrates and protein," Santiago said.
Fedick recently compiled and published a master list of indigenous Maya food plants which draws on decades of Maya plant knowledge.
He and Santiago examined all 497 plants on the list for drought tolerance.
Fedick said: "When botanists study drought resistance, they're usually talking about a specific plant, or a particular ecosystem.
“One of the reasons this project was so challenging is because we examined the dietary flora of an entire civilization — annuals, perennials, herbs, trees, domesticates, and wild species. It was a unique endeavor."
The researchers suggest that social and economic upheaval played a role in the collapse.
"One thing we do know is the overly simplistic explanation of drought leading to agricultural collapse is probably not true," Fedick added.
Last year, a mysterious new pyramid was unearthed using laser scans of an ancient ‘lost city’ of the Maya, in northern Guatemala.
Scientists using airborne light detection and ranging technology, or Lidar, spotted signs of the ancient structure near Tikal.
The ruins of Tikal in Guatemala were abandoned more than a thousand years ago, and were rediscovered by a gum sapper in 1853.
Tikal was the capital of a warring state which became one of the most powerful kingdoms of the Maya.
But the new ruins were unusual — and different from the rest of Tikal — showing off the distinctive architecture found in Teotihuacan, more than 800 miles to the west.
The pyramid-shaped complex is thought to be a replica of a square at Teotihuacan known as the Citadel, National Geographic reports.
Stephen Houston, of Brown University, said: “The similarity of the details was stunning."
Further excavations found artifacts suggesting that the site may have been a quasi-autonomous settlement within Tikal.
The city of Tikal flourished between 300 and 850 AD, and was known to the Maya themselves as Mutul.
Edwin Román-Ramírez, the director of the South Tikal Archaeological Project, said: “We knew that the Teotihuacanos had at least some presence and influence in Tikal and nearby Maya areas prior to the year 378.
“But it wasn’t clear whether the Maya were just emulating aspects of the region’s most powerful kingdom. Now there’s evidence that the relationship was much more than that.”
Watch: Meet the shaman reviving ancient Mayan chocolate rituals