29 August 2012
A Little History of Wannanosaurus
Hou Lian-hai has gone on since Wannanosaurus to become a fairly prominent Chinese paleontologist studying and writing books about mainly bird fossils. Everyone starts somewhere though, even if he does like paleo-birds more these days, and his contribution to dinosaur paleontology is quite important. The specimen found and presented to him for study was discovered in Wannan (South Anhui), hence the name, in the central portion of the eastern half of China. The Yangtze River travels directly through the area and it is fairly close to the Pacific Ocean, though not bordering it. Wannanosaurus comes from Campanian era rock of the Upper, or Later, Cretaceous period. This means it shared the globe with animals such as Ankylosaurs, other Marginocephalians of course (Ceratopsians and some other Pachycephalosaurs), birds, Hadrosaurs, and even the first flowering plants. Its nearest neighbors were animals like its cousin Homalocephale, Protoceratops, Citipati, and Velociraptor. These animals were not exactly one hundred percent in existence at exactly the same time, there is some overlap here and there, but it gives a picture of what the environment most probably looked like. Regardless, it appears, if Hou was correct in stating that the remains of Wannanosaurus come from adult individuals, that this was a very small Pachycephalosaur. Greg Paul and others have stated that the remains come from a sub-adult juvenile of the species; it is nice that they do not argue against the validity of the species but rather the maturity of the individual since there are distinguishing traits of the skull mentioned earlier which set it apart. Hopefully more complete skeletons of Wannanosaurus will be unearthed in the future to put all of these cross claims aside and give us a more complete picture of the animal because, as a basal animal, it has a lot to tell about how the Pachycephalosaurs and Ceratopsians evolved away from their common ancestor and what made each group what it became.