This giant stick insect fooled scientists for decades - Science Daily

This fossil of Diadectes, a land-adapted tetrapod that lived in North America about 290 million years ago, is on view in the Hall of Vertebrate Origins. Westlothiana is from an older, aquatic lineage. Credit: Denis Finnin/© AMNHA famous Scottish fossil is forcing scientists to rethink what claw-like feet really reveal about the move onto land. Pressed flat inside two slabs of Scottish rock, a 345-million-year-old skeleton seemed to carry some unmistakable signs of life on land. Its four limbs ended in five-digit feet, and the tips of its fingers and toes looked strikingly like claws. For decades, those features helped make Westlothiana lizziae, better known as “Lizzie,” a landmark in the story of how vertebrates moved away from water and gave rise to reptiles, birds, and mammals. Yet the fossil had been crushed so badly that much of its anatomy remained hidden inside the stone. Peering through that rock with X-rays has now exposed a very different animal.

Mud from a fjord shows an Atlantic air pattern brought wetter, colder spells to southern Greenland, a clue to how its ice may fare. Greenland’s ice is shrinking as the planet warms. But in the island’s southwest, rainfall and snowfall have been influenced by the same North Atlantic air-pressure pattern for at least 5,000 years. When that pattern tipped one way, the region turned wetter and colder. The record comes from mud on the floor of a Greenland fjord, and it suggests snowfall, not only temperature, shaped how the area’s ice grew and shrank. It doesn’t yet show how glaciers there will respond to the warming ahead. Johan Faust, a researcher at MARUM, the Center for Marine Environmental Sciences at the University of Bremen in Germany, led the work with colleagues in Germany, Norway, Denmark and Canada. A seesaw in the airThe pattern is called the North Atlantic Oscillation. It’s the difference in air pressure between a low that sits near Iceland and a high near the Azores, and it’s strongest in winter. When that difference is large, the pattern is in its positive phase. Northwestern Europe and southwestern Greenland both get more rain and snow.

Lawrence Livermore National Laboratory researcher Isaiah Santistevan led the development of three-dimensional simulations exploring how a nuclear device could deflect or disrupt an asteroid threatening Earth. Credit: Blaise Douros/LLNL Lawrence Livermore National Laboratory (LLNL) researchers are developing three-dimensional simulations to examine how a nuclear device could be used to deflect or potentially disrupt an asteroid threatening Earth.