Constructions workers in Southern California recently discovered a rare, fossilized bison skeleton while working on a state highway.

Construction was temporarily halted and the fossils were removed and are now on display at San Diego Natural History Museum, where they were unveiled Monday in a public ceremony in Balboa Park.

Experts estimate the fossil is roughly 200,000 years old, which would make it a relic of the Ice Age.

According to the museum, the find is the first ever fossilized bison discovered in Southern California.

A California law known as the Environmental Quality Act requires developers to collect fossil specimens before construction is finished, according to The San Diego Union-Tribune.  Caltrans officials said the bison was uncovered during excavations for the State Route 76 East project at Pala Mesa, near Bonsall. The state agency regularly hires scientists to watch large construction sites for important geologic or anthropologic finds.

This is not the first time ancient fossils have been uncovered during construction in San Diego. In February 2009, construction crews uncovered the tusk and skull of a mammoth believed to be 500,000 years old. San Diego's soon-to-be-completed Horton Plaza Park is also a site where many expect fossils may be unearthed.

"I'd be surprised if there weren't fossils under Horton Plaza, it's just a matter of if they've ever been discovered," a spokesperson for the San Diego Natural History Museum told local NBC affiliate 7 San Diego.