Breakthrough

Don’t get too excited by the report that our mammalian precursors from the age of the dinosaurs may have been a lot tougher than once thought. The standard view of the mammals living in the Mesozoic era, some 280 million to 65 million years ago, is that they were mousy little critters, skittering around in the dark, eating bugs and cowering in holes while the real lords, the dinosaurs, stomped around overhead until they were wiped out by some extinction event.

Now that long-held view of mammalian meekness is being challenged by two nearly complete fossil skeletons, newly discovered in China, of mammals that lived some 130 million years ago. One mammal was the size of a 30-pound dog. The other was smaller, but here’s the delicious part — its last meal had been a juvenile dinosaur, as evidenced by tiny dinosaur limbs, fingers and teeth still lodged in the mammal’s rib cage eons later. The supposedly meek mammals of that era actually dined out on the flesh of the dinosaurs. But before we hoist ourselves up the ancient food chain, it is worth noting that the victim was a tiny baby, only five inches long, and a plant eater at that. And while scientists cite some reasons for believing that the dino-eating mammal was a real predator (tough), it is likely that it was only a skulking scavenger that ate up a dead baby dinosaur (garbage eater). — The New York Times