A UCSB graduate student made a mammoth discovery earlier this month when she happened across the fossil remains of a woolly mammoth while doing survey work on Santa Cruz Island.

The archaeology student’s chance discovery of a complete mammoth tusk on Santa Cruz Island – as well as several rib bones and what are believed to be thigh bones – is one of only a few fossils of its kind found on the island and may hold answers regarding the extinction of the ancient elephant-like species. While not yet confirmed as such, researchers believe the fossils may have belonged to a pygmy mammoth – a scaled-down version of the species native to the Channel Islands.

Kristina Gill, an archeology Ph.D. student at UCSB, discovered the tusk of the pygmy mammoth earlier this month. Although Gill has participated in archaeological digs for nearly five years, mammoths are not her forte – she discovered the tusk entirely by chance.

“I wasn’t actually looking for the tusk, or even for pygmy mammoth remains in general,” Gill said. “To be honest, it’s not really my field of study. I was out there surveying on the island. [Finding the tusk] was totally accidental and unexpected.”

Over 10,000 years ago the four northernmost Channel Islands – namely Santa Cruz, Anacapa, San Miguel and Santa Rosa – were one large island that scientists have named Santarosea. Large Columbian mammoths – an ancestor of the modern day elephant – are believed to have swum the approximate 25 miles to the island in search of more space and vegetation.

Scientists speculate that these Columbian mammoths eventually evolved into pony-sized pygmy mammoths, which roamed the islands until their extinction. That the fossil was found on Santa Cruz Island – which lies directly south of Santa Barbara and Isla Vista – is significant in the fact that few mammoth fossils have been found on the island, whose geography was originally believed to have been too steep and rugged for the mammoths. If confirmed, the discovery would mean the large mammals roamed the 62,000-acre Santa Cruz Island more than previously thought.

While mammoth remains have been discovered on Santa Rosa Island in the past – including the excavation of a nearly complete skeleton in 1994 – scientists have been hard pressed to discover remnants other than small bone fragments on nearby Santa Cruz Island.

“There haven’t been very many [fossils] found on Santa Cruz and there have been none found on the northern part of the island [where the fossil was discovered],” Gill said.

Although the cause of their disappearance is unknown, a controversial debate continues among scientists as to whether the pygmy mammoths were affected by human interference – getting hunted out of existence by the Chumash – or whether they died of other causes.

Gill said the discovery of the tusk might help scientists learn more about the extinction of the species.

“With every mammoth they find out on the Channel Islands, the one big question people are trying to answer is whether people interacted and killed off the mammoths,” Gill said. “If we found that with this tusk, it would be super significant.”

The tusk will be excavated this weekend for radiocarbon dating to determine the fossil’s exact age.