Dinosaurs and Birds
Bird Evolution and Extinction
The very first birds evolved from the small, feathered theropods of the Jurassic period, after which birds spread to fill every available ecological niche: hunters, flyers, swimmers and more. Here's everything you need to know about the evolution (and extinction) of birds.
The Feathered Dinosaurs
In the Mesozoic Era, there wasn't just one "missing link" that connected dinosaurs and birds, but dozens of them: small, feathered theropods that displayed a tantalizing mixture of dinosaur and bird features. Here's what we know about these "dino-birds," as they're sometimes called.
How Feathered Dinosaurs Learned to Fly
There are two theories about how feathered dinosaurs evolved into birds with the ability to fly, which can be loosely described as "bottom up" and "top down." Here's a look at the evidence for and against each, and the current state of thinking among paleontologists.
Why Did Dinosaurs Have Feathers?
Every day, it seems, paleontologists are discovering new species of feathered dinosaurs. Why, exactly, did so many raptors, tyrannosaurs and "dino-birds" sport feathers instead of the usual reptilian scales--and what adaptive benefits did feathers bestow?
Why Aren't Birds Dinosaur-Sized?
The vast majority of paleontologists agree that birds are the direct descendants of dinosaurs. The question is, why aren't any birds the size of T. Rex or Apatosaurus--and, for that matter, why aren't any birds the size of the pterosaurs (flying reptiles) that coexisted with the dinosaurs?
Was Archaeopteryx a Bird or a Dinosaur?
Archaeopteryx is often described as the first bird, but the truth is considerably more complex than that. The question is, was Archaeopteryx closer to being a bird than it was to being a dinosaur, and what does this tell us about the evolutionary link between dinosaurs and birds?