A recently deciphered 4,000-year-old clay tablet from ancient Mesopotamia is putting a new spin on the biblical tale of the flood and Noah's Ark — and that's causing consternation among some Christian fundamentalists.

The Book of Genesis includes detailed specifications for the giant boat on which all kinds of animals were placed, two by two, to shelter from 40 days and 40 nights of rain. The wooden ark was to measure about 450 feet long, 75 feet wide and 30 feet high (300 by 50 by 30 cubits, or 137 by 23 by 13 meters).

All well and good: But the specifications listed on the Babylonian "Ark Tablet," which is now on display at the British Museum, are totally different. The Babylonian boat was supposed to be made of braided rope, stiffened by wooden spars and sealed with bitumen. And it was supposed to have a round base, measuring 230 feet wide (70 meters wide).

"It was really a heart-stopping moment — the discovery that the boat was to be a round boat," Irving Finkel, a curator at the museum, told The Associated Press. "That was a real surprise."

A circular ark is in keeping with the look of a coracle, a type of river taxi that was widely used during ancient times in the region now known as Iraq. But the layout doesn't mesh with Genesis, which is taken as the word-for-word literal truth in fundamentalist Christian circles.

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Which came first?

Finkel said the account of the flood and the ark was probably passed along to the Jews during their Babylonian exile in the 6th century B.C. and served as the basis for the Genesis story. Biblical Archaeology Review's Noah Wiener said the cuneiform tablet was created "a full millennium before the Genesis narrative was written down."



But Ken Ham, who founded Answers in Genesis-U.S. and is trying to raise $73 million to build a full-scale replica of Noah's Ark in Kentucky, says it must have been the other way around: The true account must have come first in Genesis, and was corrupted by the time the Babylonians set down their details on the Ark Tablet.



"Because the Bible is God’s inspired Word, it gives us the true account," Ham wrote. "The other flood legends are man’s changed versions of the event called Noah’s Flood, which occurred close to 4,400 years ago!"

Fans of Ham's Facebook page took up the argument and rejected Finkel's claims. "This is just another clever attempt from Satan to try to disprove or distort the existence of the ark," one said. Another wrote, "A round ark would have sunk."

Would it? We may find out: The Telegraph reports that Britain's Channel 4 has begun filming a documentary about an effort to reconstruct the circular ark. The project is a spin-off of Finkel's newly published book, "The Ark Before Noah."



More about biblical archaeology:

Alan Boyle is NBCNews.com's science editor. Connect with the Cosmic Log community by "liking" the NBC News Science Facebook page, following @b0yle on Twitter and adding +Alan Boyle to your Google+ circles. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.



