January 14, 2009

Mammoth Tusk Found On Santa Cruz Island, Maybe

Researcher reported Tuesday that a complete tusk, believed to belong to a prehistoric mammoth was uncovered on Santa Cruz Island off the Southern California coast.  If the discovery is confirmed, it would prove that the beasts roamed 62,000-acre Santa Cruz Island more widely than previously thought.

A graduate student at the University of California, Santa Barbara, discovered the tusk while working in a canyon on the island's remote north shore earlier this month.  Lotus Vermeer, the Nature Conservancy's Santa Cruz Island project director, said nearby were several rib bones and possible thigh bones.

"We've never discovered mammoth remains in this particular location on this island before," Vermeer said.

The findings will be excavated next week and will undergo radiocarbon dating to determine their age by The Nature Conservancy and a leading mammoth expert.

Santa Cruz Island is part of California's Channel Islands and is the largest of eight.  More than 10,000 years ago, during the Pleistocene epoch, the four northern islands formed one big island that scientists call Santarosae. 

Scientists have theories that mainland Columbian mammoths swam across the channel in search of vegetation of Santarosae.  Over time, they evolved into a pygmy form to better adapt to scarce resources on the islands.

Vermeer said that judging by the tusk size, about 4 feet long, it might have been a pygmy mammoth.

In 1994, the most complete skeleton of a prehistoric pygmy mammoth was excavated on Santa Rosa Island.  It is rare to find mammoth remains on Santa Cruz Island, probably because its steep terrain was in hospitable.

Researchers discovered a mammoth thigh and forelimb bone in 2005 on Santa Cruz.  Ten years earlier, a partial tusk was unearthed.  Each discovery was from a Columbian mammoth.

Curator of vertebrate zoology at the Santa Barbara Museum of Natural History, Paul Collins, was unsure of the significance of the latest find based on pictures he has seen.  Collins said it was possible the remains could have belonged to a marine mammal and said an excavation should settle the matter.

"It's very difficult to tell whether or not you're dealing with mammoth bones," he said.


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