Based on the shape of the fossil clam shells attached to the whale skeleton, Pyenson and Haasl determined that they belong to the same group of mollusks whose living relatives are chemosynthetic, confirming their initial hypothesis that this was a whale fall. A visit by Pyenson and Haasl to Ao Nuevo Island in January 2007 showed that the whale came from 15 million-year-old sediments, the Monterey Formation, making the A o Nuevo find much younger than most fossil whale falls discovered around the globe, the oldest of which date from 40 million years ago, Pyenson said.
Whale falls were unknown to science until 1989, when the first example of a deep-sea community living on recently deceased whale carcasses was reported from southern California.
"The ocean floor is pretty much a desert until you get a whole whale carcass sinking to the bottom," Pyenson said. "We don't know how these creatures know to colonize it. Are they ever-present on the sea floor waiting for an animal to fall" But when the whale carcass hits, it forms this island refuge of high nutrient levels that can sustain an undersea community, some scientists calculate, for decades."
Over the past 18 years, more whale falls have been found around the world, and paleontologists have found examples in the fossil record as well. Most fossil examples, however, consist of isolated bones adjacent to deep-sea mollusks, Pyenson said. Little is known about the size or identity of the whale host.
|Contact: Robert Sanders|
University of California - Berkeley