{"id":21211,"date":"2026-09-26T17:00:14","date_gmt":"2026-09-26T21:00:14","guid":{"rendered":"https:\/\/www.autonocion.com\/us\/?p=21211"},"modified":"2026-09-26T05:28:33","modified_gmt":"2026-09-26T09:28:33","slug":"boring-machine-chewed-mastodon","status":"publish","type":"post","link":"https:\/\/www.autonocion.com\/us\/boring-machine-chewed-mastodon\/","title":{"rendered":"A 46-foot tunnel boring machine grinding 110 feet under a Virginia harbor chewed a mastodon loose from the seabed and pumped it toward land as slurry, and an operator watching the mud for metal spotted the tooth riding by and stopped the line"},"content":{"rendered":"

Tunnel boring machines aren’t picky eaters. Whatever sits in front of the cutterhead gets chewed up, blended with water and clay into a slurry, and pumped back to daylight through a steel pipe, and nobody looks twice at that mud unless something in it could break the machine. At the Hampton Roads Bridge-Tunnel expansion<\/a> in Virginia, something in it turned out to be a mastodon.<\/p>\n

The machine doing the eating was Mary, a 46-foot German borer<\/a> that spent two and a half years cutting two highway tubes under the harbor, and whose six-month underground U-turn already got its own story here. Everything she chewed loose came back to land as slurry, headed for a treatment plant where the solids get strained out, loaded onto barges and trucks, and hauled to permitted disposal sites. One of the operators watching that flow saw a shape he didn’t like and shut the line down.<\/p>\n

Ryan Banas, VDOT’s project director for the expansion, told Construction magazine<\/a> the whole thing started with somebody at the plant saying, “Hang on a second. We need to stop production.”<\/p>\n

What he’d spotted, riding by in the muck, was a mastodon’s tooth, from an animal that disappeared from North America about 11,500 years ago.<\/p>\n

So how do you spot a tooth in a river of mud?<\/h2>\n

Mostly, you don’t. The plant Mary fed can process up to 16,000 gallons of slurry a minute, which the project likes to translate as a loaded dump truck every 10 seconds. And the people watching it aren’t looking for fossils. They’re posted there to catch anything that could have damaged the cutterhead, metal above all, because a machine named Chessie chewed into a buried English ship’s anchor<\/a> a few miles away on the Chesapeake Bay Bridge-Tunnel job and lost the better part of a year over it. Banas told Chesapeake Bay Magazine<\/a> his people get trained to spot threats to the machine. Ice Age teeth aren’t on the syllabus.<\/p>\n

So what are the odds?<\/p>\n

Pretty lousy, frankly. The operator had a few seconds while the thing slid by, and the main reason it registered at all is that a mastodon tooth doesn’t look like anything else in the ground. The chewing surface is a set of tall pointed ridges, closer to a tiny mountain range than to anything in your mouth, built for shredding branches and shrubs. Shells and clay don’t have corners like that.<\/p>\n

\n
\n
Slurry flow<\/div>\n
16,000 gal\/min<\/div>\n
One fully loaded dump truck of liquefied seabed every 10 seconds, per the project.<\/div>\n<\/div>\n
\n
Deepest dig<\/div>\n
173 ft<\/div>\n
Mary’s lowest point below the surface of Hampton Roads. The tooth came up from about 110 feet.<\/div>\n<\/div>\n
\n
ON DISPLAY<\/div>\n
The find<\/div>\n
~12 fossils<\/div>\n
A tooth, vertebrae, ribs and limb bones, none longer than 8 inches.<\/div>\n<\/div>\n
\n
The animal<\/div>\n
11,500 years<\/div>\n
The species died out in North America about 11,500 years ago. This one lived 12,000 to 50,000 years back.<\/div>\n<\/div>\n<\/div>\n

What was a mastodon doing under a Navy shipping channel?<\/h2>\n

Dying, probably in a mud pit. Banas took the find to experts at the Virginia Museum of Natural History, William & Mary and Virginia’s historic-resources department, and the consensus that came back was that a freshwater river once ran through what’s now the bottom of Hampton Roads, back when the sea sat far lower and the climate ran cooler. This one likely got stuck and couldn’t get out. The project’s own soil data brackets the deposit at somewhere between 12,000 and 50,000 years old.<\/p>\n

It’s a strange spot for an elephant relative, until you remember the coastline hasn’t always been where it is now. The new tubes run well below the harbor bottom on purpose, with the dig bottoming out 173 feet under the surface, and down at that level Mary was grinding through a packed mix of shell and clay. That’s the layer that held the animal until a 4,700-ton machine came through the neighborhood. When the tooth surfaced, per Banas, the cutterhead was sitting about 110 feet down.<\/p>\n

Mastodons, for the record, ran about the size of a modern Asian elephant, heavier built, with big tusks. They’re close cousins of the woolly mammoth, just from a much older branch of the family, one that goes back about 27 million years.<\/p>\n

The tooth didn’t come up alone<\/h2>\n

Once the belt stopped, the operator kept pulling. About a dozen pieces came off in total, none longer than 8 inches: the tooth, plus vertebrae, ribs and limb bones. VDOT’s environmental manager, Larissa Ambrose, got the state’s historic-resources people on the phone, and the answer was refreshingly practical: you can’t park a boring machine under a harbor and excavate by hand, so keep mining and keep watching the belt. The crews did. Nothing else ever showed up, and it wasn’t for lack of looking.<\/p>\n

Banas doesn’t claim they caught everything. “There may have been more of the skeleton that we missed,” he told Chesapeake Bay Magazine, and given the volume moving through that plant, I’d bet on it. Some of that mastodon very likely went through unnoticed and got barged off with the rest of the seabed. I also couldn’t pin down the exact day the tooth came through; none of the coverage gives one.<\/p>\n

The recovered pieces went to Adam Pritchard, the assistant curator of paleontology at the Virginia Museum of Natural History, whose team cleaned them, measured them, photographed them and ran them against the Smithsonian’s archive. The actual identification came from one of his colleagues, research technician Lucy Treado, who looked at one odd lump and recognized a mastodon tooth. Per Construction magazine, it’s only the third mastodon ever found in Virginia, and Pritchard’s team happened to be working on another one from a site 20 miles away at the same time.<\/p>\n

You can go stare at it<\/h2>\n

The tooth, the vertebrae, the ribs and the limb bones now sit in a display case at the project’s Welcome Center on 4th View Street in Norfolk, next to everything else the dig’s coughed up over the years: nine Civil War-era cannonballs, a WWII helmet liner, the keel of a ship, and a block of granite cut for Fort Monroe in 1819.<\/p>\n

And if you want one detail to walk away with, take this one. The boring machine is named for Mary Jackson and the slurry plant that caught the tooth is named for Katherine Johnson, two of the pioneering NASA women who worked at Langley, right across the water in Hampton. A machine named for one pulled Ice Age remains out of the seabed, and a plant named for the other caught them on the way past. Somebody at VDOT has a pretty good sense of history. Another German borer, also named Mary, is grinding under the Potomac right now<\/a>, so the family business continues.<\/p>\n

The fossils are on loan from the Virginia Museum of Natural History until the expansion wraps up, and VDOT has substantial completion set for 2027. After that, they’ll either stay on display somewhere in Hampton Roads or head back into the museum’s inventory. Either way, it beats the barge to the disposal site. Every other ounce of that seabed ended up there.<\/p>\n","protected":false},"excerpt":{"rendered":"

Tunnel boring machines aren’t picky eaters. Whatever sits in front of the cutterhead gets chewed up, blended with water and … <\/p>\n

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