With the holiday season in full swing, SB&F is pleased to share with you our picks for science books that should put a smile on the faces of your friends and family.

Chew, mash, crunch, grind... oh, the things we do with our teeth! AAAS Fellow Peter Ungar finds teeth facinating, "the product of half a billion years of evolution." Ungar is a paleoanthropologist and evolutionary biologist at the University of Arkansas. Ungar studies the tooth shape and patterns of use-wear (microscopic scratches and pits that form on a tooth's surface as the result of its use) on a wide varity of animals, apes and primates, dinosaurs and Neandertals, and our own distant ancestors.

In his recently published book, Teeth: A Very Short Introduction, Ungar provides insight into the origins of human and mammalian teeth. He looks at tooth size, shape, structure, wear and makeup to chart their development, and shows how recent changes to human diet are now affecting dental health. Ungar also demonstrates how fossil teeth are helping to fill in important gaps in the paleontological record.

Listen to Ungar read selections from the book.

• Amazon: Teeth: A Very Short Introduction
• Amazon: Mammal Teeth: Origin, Evolution, and Diversity
• Ungar Lab at the University of Arkansas

Dianna Aston introduces her picture book, An Egg Is Quiet, in this guest blog post.

A global, four-year project involving hundreds of scientists shows how avian lineages diverged after the dinosaurs’ extinction.

A tiny, furry-tailed creature was the earliest ancestor of the placental mammals—a group excluding marsupials and egg-laying mammals—and lived after the extinction of the dinosaurs, according to a study in the 8 February Science.

The origins and early evolution of placental mammals have long been a matter of debate.