Curious ancient stone is no turtle.

Byline: Winston Ross The Register-Guard

DEPOE BAY - It certainly looks like a turtle.

There's a rounded shell-like thing, with polygon-shaped cracks spaced apart in just the formation you might expect to see on a turtle's armor.

That could even be a head, jutting out from the bottom of the 20-million-year-old fossil, at least in the sense that cumulus clouds sometimes resemble dragons.

Alas, this fascinating chunk of rock, sticking out of the nye mudstone near Depoe Bay and discovered recently by a beachcomber, is probably only a feast for the imagination and not an ancient Testudines, say scientists and fossil experts who've taken a closer gander.

"It's kind of like your first blind date," said state paleontologist Bill Orr. "The closer they get, the worse they look."

Orr checked out the old rock along with Guy DiTorrice, a fossil expert, and Bill Hanshumaker, a marine education specialist with the Hatfield Marine Science Center. The trio were there in hopes of identifying an item that seemed like it might have been a turtle or a tortoise when it was first spotted a couple of weeks ago at the base of a Lincoln County resort, in a location the scientists have asked not be revealed.

Before the tides had eaten away at it enough to reveal its current form, the thing looked like it could be either a turtle, which dwells in water, or a tortoise, which dwells on land, Orr said.

"When I first saw it, it looked to me like it probably was a turtle," Orr said.

That's because of cracks in the object that resemble scutes, the bony external plates that make up turtle shells, crocodile skins and the feet of some birds. But as time exposed more of the rock, it became clear there were too many cracks for this thing to be a turtle.

"A normal turtle has 40 or 50 different individual bones that make up the shell," Orr said. "This thing has a couple hundred."

Plus, most turtles and tortoises have shells that flare out at the end, like a World War II-era German military helmet. There's no flaring evident in the Lincoln County specimen, Orr said. His fellow inspectors had to agree.

"We've gone from `It could be a turtle' to `It could be a tortoise' to `It's one huge rock that's still one of the biggest concretions we've ever seen on the Oregon Coast,'" DiTorrice said.

Though not nearly as titillating as a 20-million-year-old turtle, concretions are fairly fascinating phenomena by themselves.

A concretion is a stack of sedimentary rock made up of a mineral cement, deposited by groundwater that flows through pores between the grains of sediment. They're often found wrapping buried fossils, because the structure of the fossil creates gaps through which mineral-filled water flows, leaving this natural glue behind.

Concretions can entomb really old stuff in this way, and it may be that the rock near Depoe Bay is hiding an ancient fossil. There may even be a turtle inside it.

"Typically, the center of a concretion is something biotic," Hanshumaker said. "If you crack it in the right direction, you can see the whole fossil inside of it."

At this point, that would be too dangerous an endeavor, though.

Initially, Hanshumaker applied for a permit to remove the rock, but it's anchoring an overhang that juts out at least eight feet, he said. Pulling it out would likely cause the whole hillside, atop which sits a multimillion-dollar hotel, to come tumbling down.

"We're not sure what it is, but it's a hazard," Hanshumaker said.

Now, he's considering ground-penetrating radar for a look at what the rock might be hiding. Or, when it tumbles out on its own, likely at the hands of the next big storm, it could be taken to a hospital and X-rayed.

"We're waiting for Mother Nature to knock it off the wall," Hanshumaker said.

There's an expression in paleontology, Orr said, that describes the frustration involved in finding something you think might be spectacular but really isn't that big of a deal.

"Chicken one day, feathers the next," he said. "This is definitely a feather day."

Winston Ross can be reached at [phone] or at [e-mail].