Mystery as Mammoth Tusk Discovered 10,000ft Below Pacific Ocean, Far From California Coast

A mammoth tusk dating back at least 100,000 years has been discovered in the deep ocean off the coast of California.

Scientists were surveying the waters about 185 miles off the shore as part of a 2019 expedition to a seamount 10,000 feet below the surface. The team, using a remote operating vehicle, spotted what looked like an elephant tusk. They returned to the site two years later to retrieve it.

"You start to 'expect the unexpected' when exploring the deep sea, but I'm still stunned that we came upon the ancient tusk of a mammoth," Steven Haddock, a marine biologist from the Monterey Bay Aquarium Research Institute, said in a statement.

The tusk measures about 3 feet in length. Analysis has confirmed it belonged to a Columbian mammoth, a species that once roamed the southern part of North America, from the northern U.S., down to Mexico and parts of Costa Rica. They disappeared between 13,000 and 10,000 years ago, toward the end of the last ice age, probably as a result of habitat loss and climate change.

Haddock told Newsweek that at first they thought it might have been an elephant tusk that had fallen from an old ship. "Mammoth seemed so improbable given how far we were offshore," he said. "It took close examination on the ship and later on shore to reveal that it was indeed from a mammoth—the tiniest needle in the biggest haystack. And from there the mysteries kept piling up."

Terrence Blackburn, from the University of California Santa Cruz, is leading the team that is dating the tusk. They believe it may be the oldest, well-preserved specimen ever recovered from this part of North America. Initial analysis shows the tusk is over 100,000 years old. "Our age estimate on the tusk is largely based on the natural radioactive decay of certain uranium and thorium isotopes imparted to the tusk from the ocean. If the tusk had been found on land, deciphering its history would not be as straightforward," Blackburn said in a statement.

Beth Shapiro, professor of ecology and evolutionary biology at the UC Santa Cruz, is part of the team that will sequence and analyze the DNA of the mammoth, providing a view into the animal's life.

"Specimens like this present a rare opportunity to paint a picture both of an animal that used to be alive and of the environment in which it lived," she said in a statement. "Mammoth remains from continental North America are particularly rare, and so we expect that DNA from this tusk will go far to refine what we know about mammoths in this part of the world."

The team said it could be one of the oldest well-preserved mammoth tusks ever found in North America.

During the last ice age, glaciers covered a much larger portion of the planet than they do today. As a result of the ice being locked away, sea levels were around 400 feet lower than they are now, meaning the shore line was farther out than it is now.

Found in Pristine Condition

Mammoth fossils have been found off the coast of the U.S. before this, but never in such pristine condition.

"Other mammoths have been retrieved from the ocean, but generally not from depths of more than a few tens of meters," Daniel Fisher, whose work at the University of Michigan focuses on mammoths and mastodons, said in a statement. "This specimen's deep-sea preservational environment is different from almost anything we have seen elsewhere."

As well as learning more about the individual mammoth, the team will study the mineral crusts of the tusk to understand how it ended up so far out to sea.

"We are grateful to have a multidisciplinary team analyzing this remarkable specimen," Haddock said. "Our work examining this exciting discovery is just beginning and we look forward to sharing more information in the future."

This article has been updated with more information about the age of the mammoth tusk and quotes from Steven Haddock and Terrence Blackburn.

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