Food hoaxes occur all the time — your restaurant server brings you “red snapper’’ that’s really inexpensive tilapia, or you buy a bottle of ostensibly extra virgin olive oil that’s actually been cut with cheaper fats.

One of the grandest culinary tricks of all took place 70 years ago during a celebratory dinner at the venerable Explorers Club in New York City. Guests were told they were eating prehistoric meat, and some came away thinking they’d consumed wooly mammoth salvaged from the Alaskan permafrost. But in a new study, two Yale graduate students have used modern genetic techniques and a little shoe leather sleuthing to figure out what was really on dinner plates that night.

For one of those students, Jessica Glass, the story started when she came across a preserved meat specimen in a jar at the Yale Peabody Museum of Natural History. It bore the name of another mega-mammal from the Pleistocene era — Megatherium, the scientific name for a genus of giant ground sloth that was nearly the size of an elephant and went extinct about 12,000 years ago. The label noted that the jar contained a specimen of meat left over from a dinner at the Explorers Club on Jan. 13, 1951.

“I was always intrigued and loved that specimen,’’ Glass says. “The fact that people would eat this thing that was so old and extinct was mind-blowing to me.’’

Glass started talking with another Yale graduate student, Matthew Davis, who happened to be a member of the Explorers Club, and who knew that mammoth had supposedly been served at that legendary dinner. This posed a puzzle — was it mammoth or giant ground sloth that was eaten that night?

Either menu would have been preposterous in most settings but not at the Explorers Club. Founded in 1905, it counts Teddy Roosevelt, Jacques Cousteau, and Neil Armstrong among its members. On the night in question, place settings featured arctic rocks and vegetation sent back from Alaska, and attendees hacked apart giant chunks of glacial ice to fill their cocktails. On top of that, it’s certainly possible to find mammoth meat, preserved for millennia in ice, and make a meal of it.

“If there was ever a time when people would have eaten mammoth, it would have been at this dinner,’’ says Davis. “It’s not an extra leap.’’

Glass brought the jarred specimen to Yale’s Center for Genetic Analysis of Biodiversity, where she began to painstakingly extract a genetic sample. At the same time, Davis headed to the archives at the Explorers Club. There, he found letters between Commander Wendell Philips Dodge, the bombastic organizer of the night’s dinner, and Paul Griswold Howes, a naturalist who missed the dinner but requested a sample of the meat for display at the Bruce Museum in Greenwich, Conn., — the same sample that Glass ended up encountering years later. In the letters, Davis found clues, which suggested there was more to the mammoth meat than meets the tongue.

“Dodge has this gleeful writing style. He was an impresario, his job was to build up press,’’ says Davis. “I think he thinks it’s a joke the whole time. He starts out the letter by comparing himself to P.T. Barnum.’’

Dodge never quite came out and said the mammoth meat was a hoax, but at least to someone reading the letters today, he all but gave the game away. In particular, he wrote in fanciful, indirect terms about the possibility of a “potion by means of which’’ he could magically turn green sea turtle into giant ground sloth.

“Dodge admitted [the trick] in a vague and confusing way that Howes obviously didn’t pick up on,’’ says Glass.

Green sea turtle, as it turned out, was also on the menu that night, in the form of turtle soup. That fact, combined with the jest in Dodge’s letters, made Glass and Davis confident that neither mammoth nor giant ground sloth had slipped down anyone’s gullet at the Explorers Club. Their guess was confirmed when Glass finished her genetics work. She sequenced about 370 base pairs from a small fragment of a mitochondrial gene found in the specimen and compared it against a database of animal DNA.

“When we were sitting there clicking the computer to figure out what the meat was, we were not surprised that it was green sea turtle,’’ Glass says.

Taken one way, the news could be a little deflating. After all, a world in which a group of well-heeled adventurers dined on long-extinct megafauna is a romantic place to live. But eating, like all sensory experiences, is a matter of perception. So if the assembled guests that night went to their graves thinking they’d enjoyed a meal out of time, who’s to tell them otherwise?

Kevin Hartnett is a writer in South Carolina. He can be reached at kshartnett18@gmail.com.