The fossil is the shell of a big sea turtle called Taphrosphys sulcatus, which broke into hundreds of pieces during the eons that it lay buried in what is now near Sewell, Gloucester County.

Many of the fragments are smaller than a fingernail. There is no cardboard box with a helpful photo to show what the completed "puzzle" should look like.

And yet, little by little, the graceful curvature of an ancient reptile is emerging, as doctoral students Elena Schroeter, 27, and Paul Ullmann, 25, match up jagged edges and glue them together.

"It's a job for young eyes," said their supervisor, Kenneth Lacovara, an associate professor of biology at Drexel.

The finished product will be a nice display piece, perhaps at Drexel or its new affiliate, the Academy of Natural Sciences. It also may provide insight into various scientific questions, such as how turtles evolved and how they are related to other creatures.