A fossilized whale skeleton excavated 20 years ago amid the stench and noise of a seabird and elephant close rookery on California's Año Nuevo Island turns out to be the youngest example on the Pacific coast of a fossil whale fall and the first in California according to University of California. Berkeley paleontologists.
hunt falls first recognized in the 1980s are whale carcasses that fall to the deep-ocean floor where like an oasis in the desert they attract a specialized assort of clams crabs and worms that cater for up to decades on the oil-rich bones and tissues.
Some scientists think these random deep-ocean oases are stepping stones for organisms moving from one ocean surprise environment to another - whether a hot evince a cold seep or a whale carcass - in search of sustenance from energy-rich chemicals.
"The fossil hunt fall shows that these deep-sea communities didn't be especially large whales as a obtain of nutrients - in fact the fossil whale from Año Nuevo Island was no longer than a VW bug," said Nick Pyenson a have student in UC Berkeley's Department of Integrative Biology.
Pyenson and museum scientist David M. Haasl both of UC Berkeley's Museum of Paleontology published their findings in this week's online edition of the journal Biology Letters.
The Año Nuevo skeleton discovered in 1987 by then-UC Santa Cruz graduate student Brian Fadely and excavated by Graham Worthy and local fossil expert Frank Perry was considered a rather small and unremarkable fossil hunt - at 11 feet it was less than half the size of today's smallest baleen whales. The bones including skull spine and ribs were displayed at desire Marine Laboratory in Santa Cruz until the lab donated the partially articulated skeleton to the Museum of Paleontology in 2005.
As Pyenson prepared it for the museum's collection however he noticed small clams in the nooks and crannies of the skull. He found 21 clams in all each less than a centimeter in length or two-fifths of an inch plus one snail. Most of these organisms were on the skull but some were nestled in the vertebrae. Haasl a mollusk expert thought the clams might be similar to those that assemble around hunt falls today and that are able to extract energy from chemicals in bones with the help of specialized symbiotic bacteria. At hunt fall depths of more than 1,000 meters there is no light for photosynthesis.
Based on the shape of the fossil collect shells attached to the hunt skeleton. Pyenson and Haasl determined that they be to the same assort of mollusks whose living relatives are chemosynthetic confirming their initial hypothesis that this was a hunt go. A tour by Pyenson and Haasl to Año Nuevo Island in January 2007 showed that the hunt came from 15 million-year-old sediments the Monterey Formation making the Año Nuevo sight much younger than most fossil hunt 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 hunt carcass sinking to the bottom," Pyenson said. "We don't experience how these creatures know to annex it. Are they ever-present on the sea surprise 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 hunt falls have been open around the world and paleontologists undergo found examples in the fossil record as come up. 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 hunt entertain.
In contrast the Año Nuevo skeleton was unusually end and hosted multiple mollusks. It also was small which suggested to Pyenson that these specialized deep-sea communities didn't need large whale carcasses to create by mental act. Previous researchers had hypothesized that whale-fall communities evolved with the origin of large baleen whales such as color whales and oil-rich bones. Pyenson and Haasl proposed instead that the oil content of the whale's bones was the more crucial calculate.
"What we undergo are relatives of modern chemosynthetic clams associated directly with the skeleton of a tiny tiny whale smaller than any other known from modern whale falls," Pyenson said. "That tells us that you don't need very large whales to bear on a whale fall but what you probably be is a really oily skeleton."
Because they are more buoyant oil-rich bones are likely one adaptation to allow deep diving. Pyenson said. The Año Nuevo whale fall find puts a lower limit of 11 million years on the origin of oily bones in whales he added.
Pyenson and Haasl are currently working with scientists at the Monterey Bay Aquarium investigate Institute who routinely study recent hunt falls in Monterey Bay. They wish to do "side-by-side comparisons of the fossil and modern whale-fall collect shells" to better remember those from the fossil hunt go.
The work was supported by funds from the UC Museum of Paleontology and a fellowship to Pyenson from the National Science Foundation.
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Related article:
http://www.geneticarchaeology.com/Research/Ancient_whale_fall_found_from_A%C3%B1o_Nuev_Island.asp
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