Fossils of Ice Age Coastal Bison Found Under San Diego Freeway

The remains of an Ice Age bison have been found underneath a freeway in the northern stretches of San Diego.

A paleontologist from the San Diego Natural History Museum found the massive set of bones in early April at the junction of State Route 76 and Interstate 15 near the community of Pala Mesa, where work crews have been making freeway improvements, according to a report in U-T San Diego.

The bison bones are the latest in a series of fossil finds during freeway construction in the region.

During the recent widening of Interstate 15 in the nearby area of Rancho Bernardo, paleontologists found much older remains dating back 45 million years, including: remains of a brontothere, an extinct mammal nicknamed the "thunder beast" and related to today's rhinoceros; a flesh-eating hooved-animal; and an early lemur-like primate.

Construction over the past two years along nearby State Route 905 in Otay Mesa uncovered whale, dolphin and walrus fossils from 3.5 million years ago.

Back in 1992, crews working on State Route 54 in the south Greater San Diego area found fossilized ground sloths, a mastodon, a Dire wolf and a camel from about 200,000 years ago.

Extinct for the past 20,000 years, the Bison latifrons --- a solitary animal that lived in coastal woodlands across North America --- was an evoluntionary relative of the Plains bison, Thomas Demere, curator for the history museum's paleontology department, told U-T San Diego. .  

Adults of the discovered bison species stood up to eight feet tall at the shoulders, measured about 15 feet from tail to nose and weighed up to two tons, according to the museum, which added the animal found in North County is believed to have been a female.

"This is a time capsule that was preserved for at least one hundred thousand years until just last month," Demere said during a press conference Monday. "It's just as exciting as Christmas morning to us to see what's inside."

The recent discovery represents the most complete set of bison fossils ever found in San Diego County.