CARLSBAD — Make no bones about it, Carlsbad is one of the most significant archeological sites in the county. Over the past several years, skeletal remains of prehistoric mammals have been discovered at various construction sites in the area.

Earlier this month, the remains of a giant sloth were unearthed during the construction of the Robertson Ranch housing project on the corner of El Camino Real and Cannon Road. Last June, the remains of a prehistoric mastodon were discovered in the same general area.

“We’ve found bits and pieces in Oceanside,” said Tom Demere, the curator of paleontology for the San Diego Natural History Museum, of the prehistoric mammals. “But the remains found in Carlsbad are the most complete for both the mastodon and the sloth.”

Officials from the San Diego Natural History Museum said they believe the giant sloth roamed North County more than 11,000 years ago. According to information from the American National Museum, giant sloths roamed the earth between 10,000 and 11,000 years ago, but disappeared during the Great Ice Age.

The sloth found in Carlsbad was considered to be the smallest of the species, measuring between 7 and 8 feet long and weighing between 300 and 400 pounds.

It was the first sloth uncovered in North County and only three times have mastodon bones been found in the area, Demere said. The first two were in Oceanside in 1994 and again in 2002, and last year one was found in the Robertson Ranch development.

Prehistoric fossils from a mammoth found in Oceanside in 2001 are currently on display in the museum.

Mastodons and mammoths were both elephant-like mammals and herbivores but they did not typically compete for food.

The coastal areas are considered “hot spots” for fossils, due to geologic conditions and the types of rocks found in the area.

Over the years, finds such as ammonites, large prehistoric creatures related to the modern nautilus; an ankylosaur, the most complete dinosaur skeleton ever found in California; several brontothere, distant cousins of the rhinoceros; and a hadrosaur, a duck-billed dinosaur, have been unearthed in Carlsbad, usually during construction.

The San Diego Natural History Museum holds most of the prehistoric remains found in North County.

The new fossils will eventually be on display at the museum, or at the Agua Hedionda Lagoon Discovery Center, where the tusk and teeth from the prehistoric mastodon found last June are currently on display in locked cases until the end of July. Once the fossils are removed, replicas will replace the originals.

The sloth remains were found down the street from the Discovery Center prompting many residents of the community to rally for them to stay in the area.

“I think the remains should stay here,” said Prudence Sweeney, a docent at the Discovery Center and a longtime teacher. “I think they need to be on display, especially for children.”

Demere said it is too soon to tell what will happen to the fossils at this point.