LONDON (Reuters) - Gas-belching volcanoes may be to blame for a series of mass extinctions over the last 545 million years, including that of the dinosaurs, new evidence suggested on Thursday. A series of eruptions that formed the Deccan Traps in what is now India pumped huge amounts of sulfur into the atmosphere 65 million years ago, with likely devastating repercussions for the Earth's climate, scientists said. Gigantic eruptions, forming so-called "flood basalts," are one of two leading explanations for a series of mass extinctions that have killed off species periodically throughout history. The other theory involves asteroid impacts --...