One of the smallest known dinosaurs, Xixianykus zhangi was built for quick running. A shorter upper leg relative to its lower leg helped the dinosaur carry its weight more efficiently. A newfound ant-eating dinosaur was one of the smallest known and also one of the best adapted for running, scientists revealed... lived in a warm, temperate forested environment watered by rivers and lakes alongside duck-billed dinosaurs and likely sail-backed predators known as spinosaurs roughly 89 million to 83 million years ago. Scientists aren't sure how the dinosaur perished, but the fossil is fairly intact compared with many, so another creature...