New Data on Two Large Dinosaur Tracksites from the Upper Jurassic of Eastern Turkmenistan (Central Asia)

In this study, we present new data on the Hojapil-Ata dinosaur mega-tracksite located in the Koitendag National Park of eastern Turkmenistan, central Asia. Accurate GPS mapping, three-dimensional data on preserved tracks, and comparison with previous studies provides now a detailed database for this site. The track-bearing surface, Upper Jurassic in age, is discontinuously exposed over an area of 28.500 square meters, with 24 trackways and at least 913 footprints preserved. The collected data support the previously identified co-occurrence of the two ichnogenera Megalosauripus and Therangospodus and allow us to propose an amended systematic description of M. uzbekistanicus. In addition, a previously unreported site located a few km to the east of the main tracksite is described. The track-bearing surface extends over 24.000 square meters, and 34 trackways and 730 footprints have been mapped. These two sites represent the sole evidence of dinosaurs in Turkmenistan and they are among the largest in the world. Data collected for this study document that both localities are deteriorating at an increasing rate due to natural erosion and human activities. High-resolution laser scanner and digital photogrammetry allowed for the realization of comparable digital 3D models of dinosaur track to guarantee their fruition for future research.