When Indiana Jones sets out to recover an artifact, you can usually count on it being something on a grand scale; a golden idol bigger than his fist, for example. Or the biblical Ark of the Covenant, which requires a team of men with poles on their shoulders to heft.

But it would take thousands of the artifacts that Evan Peacock has worked with, and possibly even tens of thousands, to fill the Holy Grail, the cup of Christ that figures centrally in the third Indiana Jones adventure.

That's because Peacock, an NSF-funded researcher at Mississippi State University, studies minute snails. And while his samples may literally be small, the story they tell is sweeping in scope, encompassing an entire ecosystem and all of the recorded history, and then some, in parts of North America.

And they may just provide the key to restoring these highly endangered ecological areas.

In the diverse and specialized field of archaeology, Peacock's forte is in environmental archaeology, a relative rarity in the United States, but much more common in Europe, which is an extremely valuable tool if, as is increasingly the case, you are seeking to restore an ecosystem to its original condition. Say, for example, to the way it was prior to the advent of Europeans in what is now the United States.

"I study how nature shapes culture and vice versa. I look at human impact on the environment over the long-term," he said. "I work a lot with biologists. I am able to tell them what species should be where and in what numbers."

"I study how nature shapes culture and vice versa. I look at human impact on the environment over the long-term," he said. "I work a lot with biologists. I am able to tell them what species should be where and in what numbers."

Specifically, Peacock's snails may be found in the Blackland Prairie of Mississippi. The Mississippi variety is one of a number of "blackland prairie" ecosystems in the southeastern United States in states such as Alabama and Arkansas.

"They are some of the most endangered ecosystems around today," Peacock notes. "There are a lot of conservation dollars, both private and public, being spent to restore these areas."

But a major puzzle for those seeking to restore a landscape is this: what would the landscape we are seeking to restore have looked like, and at what period of history would it have looked that way?

And therefore, Peacock adds, unlike some other sub-disciplines of archaeology, there are a lot of applied uses for the knowledge he seeks.

With support from NSF, Peacock and his students fixed on the populations of snail in the prairies—both present day populations and their ancient counterparts—as proxies for what the state of the prairie might have been in the distant past, both prior to and after European settlement.

Since land snails were not used as food by prehistoric peoples, and so would not have been imported in trade, and because snails don't travel far, the different species are good indicators of local environmental conditions over time.

Snails, both modern and ancient, thrive in the black prairie ecosystem, Peacock explains, because "the prairies have a chalk bedrock; it's not very acidic" and therefore conducive to shell formation.

In short, "what it means is that it's snail heaven," he adds.

He had previously recovered hundreds of thousands of ancient tiny land snail shells from archaeological excavations at prehistoric Native American sites. "These are really, basically archaeological specimens," he notes.

What he and his students then did to develop a comparative picture of the prairies was to gather samples of modern snail populations. And while that may on its face seem to be a simple task, it was not, as the snails, while plentiful would not exactly catch the attention of the casual observer.

"There might be 4,000 to 5,000 snails in one sandwich bag" that was used to hold the specimens, Peacock explains.

After the modern snails were identified by officials at the Field Museum of Natural History in Chicago, and the findings compared with the ancient populations, two major findings resulted.

The first is that much of the prairie landscape visible today is radically different from what existed in the past.

Eastern Red Cedar is a very common tree in today's prairies, especially in areas where the soils are thin and eroded. The cedar glades and the open prairie grasslands share a distinctive snail community dominated by a few species. But these species are uncommon at the archaeological sites.

The second finding is that no precise modern analog was found for the archaeological snails. Although they clearly indicate a hardwood setting, no modern hardwoods were sampled that produced snail assemblages that precisely matched what was found archaeologically.

This is an indication of localized Native American environmental impact: not surprisingly, the sites where they lived developed their own peculiar environmental characteristics as people built houses, deposited garbage, trampled the ground and otherwise modified the local environment.

Peacock's work does not lay the blame for the radical shift in the landscape solely on European settlement.

"The Indians began to change the landscape," he notes, "but that just kicked into a whole other gear" with the advent of European settlement, as forest was cleared by logging and for more intensive agriculture.

The oak and hickory groves that the Indians knew gradually gave way to groves of cedar, which had at one time been a minor species in the ecosystem.

As if that weren't enough, the snails led Peacock to the answer to another major question that had been intriguing him for some time.

"There's always been sort of a mystery to me. The Black Prairie is a tough place to live because the streams dry up," he said. "So how did Indians make a go of it as farmers? The snails solved that."

Peacock and his students found remnants of amphibious snails in the ancient populations that can only thrive where the ground is wet.

Shortly after the Little Ice Age, when topsoil was largely uneroded and plentiful, Peacock concluded, "there used to be enough topsoil that held enough water that there were springs in the ground."

But, he added, "by the time Europeans showed up and started writing about these Indians, they were literally digging holes in the land to collect water," because the topsoil had gone and the springs long dried up.

"And all this from snail shells that we collected," he notes.

Golden idols, mystical Arks and sacred goblets are wonderful in works of archaeological fiction.

But, says Peacock, the snail shells and the stories they tell have taught him a very valuable overall lesson about archaeology: "You can take the most mundane materials in the world and if you can squeeze them hard enough, you can squeeze science out of them."