1. Paleontology

    Tracks suggest chase, capture, and after-meal respite

    A 1.3-meter-long, S-shaped trail of fossil footprints discovered in southwestern Indiana includes one set of disappearing tracks—suggesting an ancient chase—and an impression where the predator rested after its meal.

  2. Paleontology

    Bob, Bob, Bobbin’ Along: Dinosaur buoyancy may explain odd tracks

    New lab experiments and computer analyses may explain how some of the heftiest four-legged dinosaurs ever to walk on Earth could have left trackways that include the imprints of only their front feet.

  3. Paleontology

    Fossils of Flyers: Bones tell why Atlantic albatross disappeared

    Ancient albatross fossils suggest that rising sea levels 400,000 years ago wiped out the North Atlantic population of short-tailed albatross.

  4. Animals

    Your Spiral or Mine? Snail gene reverses coil, makes new species

    A snail with a shell spiraling to the right can't mate readily with a lefty, so changes in the single gene that controls shell direction have created new snail species.

  5. Paleontology

    Reptile remains fill in fossil record

    The fossil remains of a sphenodontian, an ancient, lizardlike reptile, are helping fill a 120-million-year-old gap between this creature's ancestors and today's tuatara, sole survivors of the once prominent group.

  6. Neuroscience

    Restoring Recall: Memories may form and reform, with sleep

    Two new studies indicate that memories, at least for skills learned in a laboratory, undergo a process of storage and restorage that depends critically on sleep.

  7. Animals

    Bad Bubbles: Could sonar give whales the bends?

    Odd bubbles of fat and gas have turned up in the bodies of marine mammals, raising the question of whether something about human activity in the oceans could give these deep divers decompression sickness.

  8. Animals

    Carnivores in Captivity: Size of range in wild may predict risk in zoo

    A survey of zoo reports of troubled animals suggests that the minimum size of a species' range predicts how well it will adapt to captivity.

  9. Paleontology

    Some trilobites grew their own eyeshades

    The 380-million-year-old fossil of a trilobite strongly suggests that members of at least some trilobite species were active during the daytime, a lifestyle that scientists previously had only suspected.

  10. Plants

    Bean plants punish microbial partners

    In a novel test of how partnerships between species can last in nature, researchers have found that soybeans punish cheaters.

  11. Ecosystems

    Killer Consequences: Has whaling driven orcas to a diet of sea lions?

    Killer whales may have been responsible for steep declines in seal, sea lion, and otter populations after whaling wiped out the great whales that killer whales had been eating.

  12. Animals

    Leashing the Rattlesnake

    Even in the 21st century, there's still room for old-fashioned, do-it-yourself ingenuity in experimental design for studying animal behavior.