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Dinosaur Bone Study Reveals That Not All Giants Grew Alike
A survey of prehistoric bones reveals that T. rex and some of its cousins had more than one way to reach enormous sizes. Evolution may have preserved that variation in modern animals too.
A Rapid End Strikes the Dinosaur Extinction Debate
The paleontologist Pincelli Hull has nailed down the timing and speed of the extinction that killed off the dinosaurs — details that carry ominous warnings for today.
Complex Animals Led to More Oxygen, Says Maverick Theory
For decades, researchers have commonly assumed that higher oxygen levels led to the sudden diversification of animal life 540 million years ago. But one iconoclast argues the opposite: that new animal behaviors raised oxygen levels and remade the environment.