Construction workers at the Quarry Creek development site in Carlsbad, California, have discovered important Ice Age Mammoth and bison fossils during the earth moving operation at the site, NYC Today reports.

The fossils have been taken to the San Diego Museum of Natural History for examination and storage. The bison skull and skeleton will be displayed at the museum.

The fossils include bison skull and partial skeleton, Columbian Mammoth, horses and turtles.

Tom Demere, curator of paleontology at the San Diego Museum of Natural History said that the age of the fossils could be dated be 50,000 to 200,000 years old.

"The bison fossil, which includes a skull and partial skeleton, is the most unusual and probably the most complete of the larger animals found at the project site. These are big animals, much larger than modern plains bison," said Deméré.

According to San Diego Union Tribune, the only other bison fossil ever found in San Diego County was discovered about three years ago at a Caltrans construction site near Pala.

Paleontologists are now working closely with the property developer, San Diego-based Cornerstone Communities. The team members of Cornerstone Communities worked with paleontologists to remove the fossils. The museum will continue to look for more fossils in the Quarry Creek area.

Previously, fossils have been found at downtown San Diego, Oceanside, Fairbanks Ranch and the Anza Borrego Desert.

Cornerstone CEO Ure Kretowicz said,

"It's a perfect example of how a mass grading operation can still be sensitive to historical and paleontological concerns. We stop everything or go grade another area on the site."