Palaeontologists visiting a 800-year-old stone structure, typical for Ancestral Puebloans discovered fossilised tracks of a theropod dinosaur on a rock slab used as a lintel for the door.
The slab with the prints must have been transported to this cliff dwelling and deliberately places as the lintel by the builders. The cliff-dwelling was known to archaeologists but the dinosaur tracks in the lintel were so far unnoticed. The discovery is first for the practice of incorporating track fossils into cliff structures in American Southwest. The structure was built and occupied over several phases of Ancestral Puebloan history. Its parts date back to the early phase known as Basketmaker II, when Ancestral Puebloans began to experiment with agriculture and build permanent settlements, starting about 2,500 years ago. Most of the structure however are dated to the Pueblo III period, from about 1150 to 1350 AD.
The three-toed tracks are said to belong to a Grallator, a theropod that reached up to three meters in length. Judging by the rock, the dinosaur tracks must have been left at least 200 million years ago, in the Late Triassic Chinle Formation or the Early Jurassic Kayenta Formation.
(after Western Digs)