MANTUA TWP. Six-year-old Daniel Konkle ran up to the head paleontologist and held out a circular clump of dirt. "What's this? Is this something?"

"That's a consolidation," Kenneth Lacovara, director of Drexel University's paleontology and geology department, said.

"What's a compstilation?" Daniel asked, looking up from under a baseball cap, a roaring T-Rex emblazoned on the front of his shirt.

"It's a packed-together bunch of soil," Lacovara said."

With that, Daniel threw his find to the ground and sprinted back up the mountain of sediment where 65 million-year-old fossils were waiting to be unearthed.

The second annual Mantua Dig Day, a collaboration between the township and Drexel, brought 850 people, mostly children, from all over the Northeast to the home of a rare and potentially unique bed of history.

The site was discovered more than 70 years ago by farmers who, while digging through the green marl pits, found fossils from 65 million years ago. The land was underwater then and home to mosasaurs (green komodo-dragon-like sea monsters) and plesiosaurs (think Loch Ness monster.)

This year, Boy Scout troops, families, science classes, and individuals took a shuttle from a nearby shopping mall and were dropped into what looked like a different world. Participants could dig in two designated areas of the 65-acre property and got to keep what they found, mostly fish vertebrae, bone fragments, and crustaceans.

Peggy Culbert, a retired music teacher from Sewell, returned to the site for the first time in 52 years Saturday. She first visited with her Brownie troop when she was 7 years old.

"I remember because I found a shark tooth then," she said, holding a bag of the less exciting, but more common, clam species. "It's really an amazing place. It's hard to believe it's right here."

The property, owned by the Inversand Co., has led to the development of a new major at Drexel in geoscience. Lacovara said he hopes the site becomes a "gateway to get kids interested in the sciences."

Inversand, the Township of Mantua, and Drexel are working on a preliminary proposal to create a fossil museum and education center to expand access to the site.

The interest is there, said Michelle Bruner, Mantua's economic development coordinator.

This year nearly 200 people were wait-listed for the dig, which can accommodate only about 850. Those people will get first dibs next year, Bruner said.

But will any fossils be left for them to find?

Lacovara laughed.

"If we excavated five days a week it would take 10 years to excavate an acre. With 65 acres, that's 650 years of fossil potential here."