Age of the pterosaur and web-footed bird tracks associated with dinosaur footprints from South Korea |
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| Authors: | Cheong-Bin Kim Min Huh Chang-Sik Cheong Martin G Lockley Ho-Wan Chang |
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| Institution: | School of Earth and Environmental Sciences (BK 21), Seoul National University, Seoul, 151-742, Korea, (email: ),;Faculty of Earth Systems and Environmental Sciences &Dinosaur Research Center, Chonnam National University, Kwangju, 500-757, Korea,;Korea Basic Science Institute, Taejeon, 305-333, Korea and;Department of Geology, University of Colorado at Denver, Denver, Colorado, 80217-3364, USA |
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| Abstract: | Abstract An absolute age has been determined for the Cretaceous Uhangri Formation in which web-footed bird tracks, pterosaur tracks and dinosaur tracks have been discovered recently. This combined track discovery is a first from Asia. There is one other similar find in the world, however, the Uhangri site is greater in abundance and frequency. Moreover, the size of the pterosaur tracks indicates that the track maker had a wingspan of 10 m or more. Well-preserved tuffaceous rocks in the formation made it possible to measure geological age by Rb–Sr and K–Ar methods. Rb–Sr whole rock ages for the volcanic rocks are: 96.0 ± 2.5 Ma (MSWD = 0.354) for lapilli andesitic tuff, 81.0 ± 2.0 Ma (MSWD = 0.296) for felsic tuff and 77.9 ± 4.1 Ma (MSWD = 4.41) for Hwangsan welded tuff. K–Ar ages are younger, 83.2–68.8 Ma. The layer containing fossil tracks of pterosaurs and web-footed birds are preserved in black shale sandwiched by the lapilli andesitic tuff and felsic tuff, and are thus 96–81 Ma in age. Dinosaur footprints are dated at 96–78 Ma. Thus the pterosaurs, web-footed birds and dinosaurs coexisted in the same environment from Cenomanian to Campanian time. |
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| Keywords: | Cenomanian to Campanian Cretaceous Uhangri Formation dinosaur tracks pterosaur Rb–Sr age web-footed bird |
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