Sixteen miles from Grand Canyon's south rim, a cone-shaped butte rises like a lone sentinel 1,000 feet above the Coconino Plateau floor. Thousands of tourists rush past on Arizona Highway 64 without giving it another thought, yet this humble little hill testifies to a remarkable past.

Lagerstätten is a word creationists should be familiar with. German for "place, of storage [or] resting place" it refers to a sedimentary deposit extraordinarily rich in the diversity or quality of preservation of its fossils. Paleontologists distinguish two kinds. Concentration lagerstätten are deposits with a peculiar abundance of broken-up hard parts, such as a bone bed.