 The long-necked, long-tailed herbivore lived an estimated 150 million years ago during the late Jurassic era, making it older than the T. rex. Most dinosaur fossils are brown or black. The rare green color is from the mineral saladinite, which forms in volcanic or hydrothermal conditions, which usually destroy buried bones. I'm Daniel Martindale. WGCH News Center Times, 858. Nobody knows like Pinocchio knows. He knows our business.