Wow. I'd like to bring your attention to this recent post by Alton Dooley on the Virginia Museum of Natural History's blog "Updates From the Vertebrate Paleontology Lab". This quarry is famous for its exquisite preservation, especially of Late Triassic insects. Small "reptiles" such as Tanytrachelos, especially articulated ones, are extremely rare to unknown from the Chinle Formation due to the lack of strata with this type of preservation. In Petrified Forest National Park we get fine-grained shales that preserve mostly plant material (leaves, stems), as well as the occasional invertebrates (unionids, isolated insect wings, and our best find, a fresh water lobster!),; however, these layers are seemingly devoid of vertebrates (although I still try from time to time, something I like to call "playing the slot machine").