One body rests on its left side, head and neck pulled back toward the pelvis--a classic death pose. The arms and legs are still in their anatomically correct positions, but closer inspection reveals that bones of the hands and feet are dislocated, although most parts are present and accounted for. The skull, too, is somewhat disjointed, and here again the component pieces lie near one another. Curiously, the tip of the tail is missing altogether. Nearby rest more corpses in markedly different states of preservation and disarray. Some are still largely intact, others represented by only a skull, a shoulder blade, a single limb bone. Did the unfortunate creatures die here, or were they brought together after their demise? Did they all perish at the same instant, or did their deaths transpire over time? And what killed them?

Our team of Malagasy and American paleontologists and geologists started asking such questions as soon as we discovered the mass grave in the summer of 2005 in the ancient sediments of northwestern Madagascar, an island whose Venetian-red soils inspired its nickname, the Great Red Island. We turned up some intriguing information as we searched for the answers, but how we went about the task is perhaps as interesting as what we found.