Theropod, avian, pterosaur and arthropod tracks from the Latest Cretaceous of Paredon, Coahuila, northeastern Mexico, and their significance for the end-Cretaceous mass extinctiion
Final Report Abstract
We here revise two unique localities that combine an unusual diversity of avian, pterosaurian and dinosaur tracks as well as trails of invertebrates, namely arthropods. They were recently discovered by us in uppermost Maastrichtian siliciclastic sediments of the Las Encinas Formation in the Mexican state of Coahuila, about 40 km north of Saltillo. The majority of these trackways, at Amargos and Rancho San Francisco, was produced by at least five different types of birds, while trackways of azhdarchoid pterosaurs are rare and only a single footprint of a non-avian theropod was found. A diverse ichnofauna of invertebrates, especially arthropods, is also present in a different facies. The tetrapod trackway assemblage was deposited during the very latest Maastrichtian as is indicated by an up to 2.5 meter thick unit with abundant smectite spherules attributed to the Chicxulub impact at less than 8.5 meters distance up-section at Amargos. Sphenodiscus pleurisepta is the last ammonite at Amargos and may have crossed the K/Pg boundary into the earliest Paleocene.
Publications
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(2015): Age and depositional environment of the "dinosaur graveyard” at Las Águilas, southern Coahuila, NE Mexico. - Palaeoecology, Palaeoclimatology, Palaeobiogeography, 441, p. 758-769
Vogt, M., Stinnesbeck, W., Zell, P., Kober, B., Kontny, J. Herzer, N., Frey, E., Rivera, H., Padilla Gutierrez, J.M., Amezcua, N. & Flores Huerta D.
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(2015): Upper Campanian (Upper Cretaceous) cephalopods from the Parras Shale near Saucedas, Coahuila, Mexico. - Journal of South American Earth Sciences 64, p. 229-257
Ifrim, C. Stinnesbeck, W., Espinoza, B. & Flores Ventura, J.
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(2016): The Cretaceous-Paleogene boundary at Gorgonilla Island, Colombia, South America. - Terra Nova, 28, p. 83-90
Bermúdez, H.D., García, J., Stinnesbeck, W., Keller. G., Rodríguez. J.V., Hanel, M., Hopp, J., Schwarz., W.H., Trieloff, M., Bolívar, L. & Vega, F.J.
