What did Homo sapiens eat 170,000 years ago? Roasted, supersized land snails

Sluggish-motion giant land snails made for straightforward catching and good consuming as early as 170,000 years in the past.

Till now, the oldest proof of Homo sapiens consuming land snails dated to roughly 49,000 years in the past in Africa and 36,000 years in the past in Europe. However tens of hundreds of years earlier, individuals at a southern African rock-shelter roasted these slimy, chewy — and nutritious — creepers that may develop as huge as an grownup’s hand, researchers report within the April 15 Quaternary Science Critiques.

Analyses of shell fragments excavated at South Africa’s Border Cave point out that hunter-gatherers who periodically occupied the location heated giant African land snails on embers after which presumably ate them, say chemist Marine Wojcieszak and colleagues. Wojcieszak, of the Royal Institute for Cultural Heritage in Brussels, research chemical properties of archaeological websites and artifacts.

The supersized delicacy turned particularly in style between about 160,000 and 70,000 years in the past, the researchers say. Numbers of unearthed snail shell items have been considerably bigger in sediment layers courting to that point interval.

New discoveries at Border Cave problem an influential concept that human teams didn’t make land snails and different small recreation a giant a part of their food regimen till the final Ice Age waned round 15,000 to 10,000 years in the past, Wojcieszak says.

Lengthy earlier than that, hunter-gatherer teams in southern Africa roamed the countryside gathering giant land snails to carry again to Border Cave for themselves and to share with others, the workforce contends. Among the group members who stayed behind on snail-gathering forays might have had restricted mobility because of age or damage, the researchers suspect.

“The straightforward-to-eat, fatty protein of snails would have been an essential meals for the aged and babies, who’re much less in a position to chew arduous meals,” Wojcieszak says. “Meals sharing [at Border Cave] reveals that cooperative social habits was in place from the daybreak of our species.”

Border Cave’s historic snail scarfers additionally push again the human consumption of mollusks by a number of thousand years, says archaeologist Antonieta Jerardino of the College of South Africa in Pretoria. Earlier excavations at a cave on South Africa’s southern tip discovered proof of people consuming mussels, limpets and different marine mollusks as early as round 164,000 years in the past (SN: 7/29/11).

Given the dietary worth of enormous land snails, an earlier argument that it was consuming fish and shellfish that energized human mind evolution might have been overstated, says Jerardino, who didn’t take part within the new research.

It’s not shocking that historic H. sapiens acknowledged the dietary worth of land snails and infrequently cooked and ate them by 170,000 years in the past, says Teresa Steele, an archaeologist on the College of California, Davis who was not a part of the work. However intensive consumption of those snails beginning round 160,000 years in the past is surprising and raises questions on whether or not local weather and habitat adjustments might have diminished the provision of different meals,  Steele says.

Researchers have already discovered proof that historic individuals at Border Cave cooked starchy plant stems, ate an array of fruits and hunted small and enormous animals. The oldest identified grass bedding, from round 200,000 years in the past, has additionally been unearthed at Border Cave (SN: 8/13/20).

A number of excavations have been performed on the web site since 1934. Three archaeologists on the brand new research — Lucinda Backwell and Lyn Wadley of Wits College in Johannesburg and Francesco d’Errico of the College of Bordeaux in France — directed the most recent Border Cave dig, which ran from 2015 by means of 2019.

Discoveries by that workforce impressed the brand new investigation. Excavations uncovered shell fragments of enormous land snails, many discolored from doable burning, in all however the oldest sediment layers containing remnants of campfires and different H. sapiens exercise. The oldest layers date to at the least 227,000 years in the past.

Chemical and microscopic traits of 27 snail shell fragments from numerous sediment layers have been in contrast with shell fragments of recent giant African snails that have been heated in a metallic furnace. Experimental temperatures ranged from 200° to 550° Celsius. Heating occasions lasted from 5 minutes to 36 hours.

All however a couple of historic shell items displayed indicators of prolonged warmth publicity per having as soon as been connected to snails that have been cooked on scorching embers. Heating clues on shell surfaces included microscopic cracks and a uninteresting end.

Solely decrease components of enormous land snail shells would have rested in opposition to embers throughout cooking, presumably explaining the combo of burned and unburned shell fragments unearthed at Border Cave, the researchers say.