It would be a memorable sight. But it would also be so wrong to tip over Galápagos giant tortoises to see how shell shape affects their efforts to leg-pump, neck-stretch and rock right-side up again.

Peggy and Steve Davis stumled upon this shell cracked in the shape of a cross while on vacation on Hilton Head Island. Submitted Standing on Hilton Head Island’s deserted beach and looking out at the ...