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On a sunny summer day in Croatia several years ago, an archaeologist and two dog handlers watched as two dogs, one after another, slowly worked their way across the rocky top of a wind-scoured ridge.

Bodies had lain in beehive-shape tombs on this necropolis since the Iron Age. The dogs, trained to detect human remains, were searching for scents of years old.

Panda, a Belgian Malinois with a “sensitive nose,” according to her handler, Andrea Pintar, had begun exploring a tomb when she froze, her nose pointed toward a burial chest. This was her signal that she had located the scent of human remains.

Archaeologists had found fragments of human bone and teeth in the chest, but these had been removed months earlier.

Human-remains detection dogs, or cadaver dogs, are used worldwide. But the experiment in Croatia marked the start of one of the most careful inquiries yet carried out of an unusual archaeological method. If such dogs could locate the burial sites of mass executions, dating from World War II through the conflicts in the Balkans in the 1990s, might they be effective in helping find ancient burials?

Panda and another Belgian Malinois, named Mali, seem to suggest the answer is yes. Each gave her final indications that day by either sitting or lying inside the flattened circle of the tombs, their noses pointing toward the burial chests within. In some cases they leapt into the small burial chests before offering an alert.

The expedition had been initiated by Vedrana Glavaš, an archaeologist who had excavated the site and analyzed three tombs there. Each chest once held at least two bodies, which were 2,700 years old.

But were there other tombs on the site, and could the dogs locate them?

“I think dogs are capable of this, but I think it’s a logistical challenge,” said Adee Schoon, a scent-detection-animal expert who was not involved in the study. He said something as subtle as recently disturbed soil can elicit a false alert from a dog that is not rigorously trained.

Nonetheless, the team returned to the necropolis for the first controlled tests in September 2015, and again a year later. Both times, they used four cadaver dogs. The dogs located four tombs new to the archaeologists. Glavaš had suspected that a fifth site might hold a burial chest, and the dogs’ alerts, combined with excavation, proved her suspicion correct.

Panda and Mali aren’t the only dogs that have helped locate human archaeological remains. In the United States, human-remains detection dogs have aided discoveries at a variety of Native American sites.

Mike Russo and Jeff Shanks, archaeologists with the National Park Service’s Southeast Archeological Center, had created at least 14 test holes in Florida that had been flattened during an earlier era of archaeology. They found nothing.

“We knew where it should be, but when we went there, there was absolutely no mound,” Russo said.

They then asked handler Suzi Goodhope to bring her detection dog, Shiraz, to the site in 2013. Shiraz and Goodhope worked the area for a long time. Then, Shiraz sat. Once.

“I was pretty skeptical,” Shanks said.

Nonetheless, the archaeologists dug. And dug. They went down nearly 3 feet — and there they found a human toe bone more than 1,300 years old.