Bird brains left other dinosaurs behind

Today, being "birdbrained" means forgetting where you left your keys or wallet. But 66 million years ago, it may have meant the difference between life and death—and may help explain why birds are the only dinosaurs left ...

Fossil dental exams reveal how tusks first evolved

A wide variety of animals have tusks, from elephants and walruses to five-pound, guinea pig-looking critters called hyraxes. But one thing tusked animals have in common is that they're all mammals—there are no known fish, ...

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