Scientists in China on Wednesday described one of the weirdest flying creatures ever discovered: a pigeon-size dinosaur with wings like a bat that lived not long before the first birds. The dinosaur, named Yi qi (meaning "strange wing" in Mandarin and pronounced EE-chee), lived about 160 million years ago during the Jurassic Period, about 10 million years before the earliest-known bird, Archaeopteryx. It is considered a cousin of birds, but boasted membranous wings made of...