A Mesa Southwest Museum team excavating the remains of a Columbian mammoth from a Gilbert construction site believes the dig may yield many prehistoric animal bones.
Robert McCord, the museum’s curator of natural history, said at a news conference Wednesday that the pelvis of a giant tortoise was found. The tortoise was at least 2 feet long — larger than modern tortoises — and is either a member of an extinct breed or one that no longer lives in Arizona.
McCord said the bones of the Columbian mammoth, the tortoise and possibly more creatures appeared to have collected there tens of thousands of years ago because of running water or a flood. They lay undiscovered, six feet underground, until a construction worker recently spotted a vertebra belonging to the mammoth.
The cache of bones is stuck in muddled, coarse soil mixed with pebbles. McCord and museum employee Gavin McCullough are spending early mornings meticulously unearthing them.
"Getting them out means picking one pebble at a time out," McCord said.
The construction site’s developer, Woodbine Southwest, has allowed the museum team 30 days to excavate the bones, said Buzz Gosnell, company president.
"They’re clearly not in the path of any construction right now," Gosnell said, adding that the area is intended as a drainage basin. The site’s location and the name of the development are not being disclosed because of concerns about vandalism.
A similar paleontological dig in 1997 in Chandler was compromised when vandals stole mammoth bones after media reports of their location.
The excavation process is designed to preserve the fragile legacy of the mammoths that roamed the Southwest more than 10,000 years ago. McCord said the Columbian mammoth is believed to have been one of the largest elephantlike mammals, standing about 14 feet at the shoulder and weighing up to 10 tons.
"They were truly an impressive critter," he said.