Analysis of a fossil suggests plumage first evolved for display, not flight.

Researchers find microscopic structures in some fossils that may have held pigments.

Better weather forecasts could help farmers avoid unnecessary pesticide spraying.

Fossils of an ancient animal don’t typically include much more than the creature’s hard parts — sometimes intact, but often shattered to smithereens. Lucky paleontologists may stumble upon a well-preserved, nearly complete skeleton that offers a rough idea of an animal’s size and shape. But fossils that preserve soft tissues — skin, flesh, feathers — are the rarest of the rare. These geological treasures form and survive only under special environmental conditions that scientists are just now beginning to understand. Bones give just an overall hint of what an animal such as a f... (p. 22)

Once-rare organisms can become dominant, probably as some environmental conditions change over time. (p. 11)

Newly discovered trackways much older than previous evidence for sea-to-land transition. (p. 9)

Fossils show depression in upper jaw that held venom-producing glands. (p. 9)

Earth sciences reporter Sid Perkins blogs on new research from the annual meeting of the American Geophysical Union in San Francisco.

Seafloor eruption in the South Pacific is the deepest and most violent yet seen. (p. 14)