A 15-million-year-old whale, discovered in 1987 by a University of California-Santa Cruz graduate student, has finally yielded its secrets to paleontologists.

 

Brian Fadely, who discovered the bones embedded in the cliffs on Año Nuevo Island, a preserve administered by UCSC off the coast of San Mateo County, knew it was an important find when he brought the skull back to his lab. But it took 20 years for researchers to notice the tiny fossilized clams wedged in the crannies of the bones, which indicate it’s not just a fossil of a whale, but a “whale fall”—a group of creatures that live on a dead whale. The find will help scientists understand how the ocean’s food chain works.

 

“It’s just stunning to me that it has something to do with whale fall communities,” said Fadely, now a wildlife biologist at the National Marine Mammal Laboratory in Seattle.

 

The Año Nuevo skeleton is one of the most complete fossil whale falls ever described, and the first such fossil to be found in California. It’s forcing scientists to rethink what kind of whales can actually support a whale fall.

 

“I wouldn’t have expected a whale-fall community to have built up on a whale that small,” said Bob Vrijenhoek, an evolutionary geneticist who studies whale falls at the Monterey Bay Aquarium Research Institute in Moss Landing.

 

Scientists thought only large baleen whales, like the 80-foot blue whale, could support such a community. The Año Nuevo skeleton is around 11 feet long.

 

“It’s about the size of a VW bug,” said Nick Pyenson, the UC-Berkeley graduate student who studied the clamshells.

 

For the creatures in the deep sea, a sinking whale carcass is a feeding frenzy. Sharks and slimy hagfish scavenge the flesh from the bones. Bacteria form furry mats along the skeleton. An array of critters—at least 400 species, experts say—makes the dead whale their home.

 

Fadely, a physiology student, wasn’t looking for fossils that day in 1987. He was on Año Nuevo for the elephant seals when he noticed a skull peering out of the rock.

 

When Fadely pried out the skull, he was struck by its 40-pound weight—too heavy for bone—and he knew it must be a fossil.

 

“I realized it was something way more important than I’d originally thought,” Fadely said.

 

He took the skull back to Santa Cruz and a passing scientist identified it as a small baleen whale.

Frank Perry, a research associate at the Santa Cruz Museum of Natural History, excavated the rest of the skeleton, including parts of the backbone, ribs, and a flipper. It spent a decade on display at the UCSC’s Joseph M. Long Marine Lab before moving to the UC Museum of Paleontology.

 

There, Pyenson noticed the tiny shells, about the size of a pinkie fingernail, where the whale’s nose used to be. He found 21 clamshells, relatives of modern whale-fall clams, and part of a snail shell. His study was published in the December issue of the journal Biology Letters.

 

Now that size isn’t a requirement for whale-fall formation, Pyenson thinks that the oily bones may be the most important factor. Whale bones are up to 60 percent oil by weight. That’s what attracted whalers in the 1800s—oil to fuel lamps. And oil is what provides nourishment for the whale fall dwellers.