William Parker has been employed as the lead paleontologist at Petrified Forest National Park in Arizona since 2001, where he established and leads the park's vertebrate paleontology research lab. Since 2002, park staff have published more than 50 papers on the geology and paleontology of the Triassic Period. Dr. Parker has B.S. and M.S. degrees in geology from Northern Arizona University and a Ph.D. in geology from the University of Texas at Austin. He is considered an expert in the study of Triassic archosaurian reptiles and on the geology and stratigraphy of the Upper Triassic Chinle Formation of Arizona.