Researchers say rare fossil evidence provides evidence of one type of evolution . 20 fossilized pterodactyls found in China in rock dating back 50 million years . They show creatures had one of two types of evolved pterodactyls . Scientists say fossils show groups of features changed relatively rapidly .
Researchers say rare fossil find provides evidence of one theory of evolution . 20 fossilized pterodactyls found in China in rock dating back 160 million years . Fossils show creatures had characteristics of two types of known pterodactyls . Scientists say fossils show groups of features changed relatively rapidly .