So much for the man-sized snail, plus Indonesia’s quake risk, overheated reefs and more in this week’s news

ACTUALLY TINY It turns out this 2-meter-long snail fossil was probably made by the corkscrew path of an eensy threadworm. Shell: PaulDTaylor/Wikimedia Commons; Figure: dem10/iStockphoto
CTYPE html PUBLIC “-//W3C//DTD HTML 4.0 Transitional//EN” “”> Snail knocked down to size After 90 years, paleontologists at London’s Natural History Museum have demoted a man-sized snail to a tiny worm track. In 1921, British construction workers dug up a spectacular 2-meter-long corkscrew fossil; museum paleontologists dubbed it Dinocochlea ingens , or “terrible snail.” But now Paul Taylor and Consuelo Sendino say the fossil is nothing more than the traces of a threadworm just a few millimeters across. The worm burrowed in a corkscrew path, and sand grains cemented and enlarged the burrow to fantastic size, the scientists write in an upcoming Proceedings of the Geologists’ Association . — Alexandra Witze Quake alert for Indonesia A big geologic fault off Sumatra’s coast has awakened after three decades of slumber. The Mentawai fault experienced two unprecedented spasms of earthquakes in 2005 and 2009, seismologists have found — possibly because three great quakes, including the one that spawned the deadly Indian Ocean tsunami in 2004, have hit nearby. New studies of the Mentawai spasms reveal it may pose a greater risk to Indonesia than scientists had thought. A team led by Kelly Wiseman of the University of California, Berkeley reports the finding in an upcoming Geophysical Research Letters . — Alexandra Witze Dioxins can delay male puberty The higher the concentration of dioxins in a boy’s blood, the later he is likely to enter puberty, an international team of researchers reports. Their new data, published online April 28 in Environmental Health Perspectives , add to growing evidence that these widespread environmental pollutants can perturb the normal development of reproductive tissues. The median dioxin levels in the 489 Russian boys studied was around 21 picograms per gram of blood (roughly triple the European average), although some boys had more than 150 picograms per gram. The new observations, consistent with what has been seen in rodents, link elevated dioxin concentrations with delayed testicular maturation. — Janet Raloff Warming puts brakes on reef fish Tropical fish — many of which evolved to thrive in a relatively narrow environmental niche — may prove especially vulnerable to global warming, a new study suggests. Scientists at James Cook University in Townsville, Australia, subjected 10 species of damselfish to water 3 degrees Celsius warmer than their preferred temperature. Swimming performance in half of the species dropped by 20 to 50 percent. Metabolism and oxygen use was also substantially impaired in half of the species. Multiple species tested would have “less swimming capacity than required to overcome the water flows commonly found in their respective coral reef habitats,” the authors report online April 28 in Global Change Biology . — Janet Raloff

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