Caudipteryx dinosaur. Computer illustration of a Caudipteryx sp. dinosaur. This small bird-like omnivorous theropod dinosaur lived during the early Cretaceous period (about 125 to 130 million years ago) in what is now China and reached approximately 80 centimetres in length. Some scientists see Caudipteryx as a link between reptiles and birds, however some believe that it is a descendent of more ancient birds.