Woolly mammoth was never served at a lavish 1950s New York dinner where rare and extinct species were trumpeted as being on the menu, a researcher has said after putting leftover meat through DNA analysis.

The Explorers Club soiree became folklore after it was said to have included 250,000-year-old extinct mammoth. Meat from a giant ground sloth was also promised.

But a DNA analysis from a fist-sized piece of meat kept as a souvenir showed something more mundane: sea turtle.

“I’m sure people wanted to believe it. They had no idea that many years later a PhD student would come along and figure this out with DNA sequencing techniques,” said Jessica Glass, a Yale graduate student and co-lead author of a study published in the journal PLOS ONE.

The Explorers Club gala, held in the grand ballroom of the Roosevelt Hotel, promised a menu of Pacific spider crabs, green turtle soup, bison steaks and meat from an extinct giant ground sloth, according to Adalgisa Caccone, a senior research scientist and study co-author.

Some of the folklore about mammoth being on the menu apparently grew out of a Christian Science Monitor story that ran days after the January 1951 event. It reported that the “chief attraction at the smorgasbord was a morsel of 250,000-year-old hairy mammoth meat”.

It apparently had been found at “Woolly Cove” on Akutan Island, in the Aleutians, and was shipped to New York. According to Yale, the banquet’s promoter, Commander Wendell Phillips Dodge sent out press notices saying the annual dinner would feature “prehistoric meat”.

An Explorers Club member, Paul Griswold Howes of the Bruce Museum in Greenwich, Connecticut, was unable to attend the dinner but requested a piece of the meat be sent to him. Although the sample was labeled as “Megatherium”, or giant sloth, the myth about the wooly mammoth persisted over the decades.