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Dinosaur graveyard at Las Águilas, Coahuila, Mexico.
Ben Creisler
bcreisler@gmail.com
A new paper:
Manfred Vogt, Wolfgang Stinnesbeck, Patrick Zell, Bernd Kober, Johanna
Kontny, Nina Herzer, Eberhard Frey, Héctor E. Rivera-Sylva, José
Manuel Padilla Gutierrez, Natalia Amezcua & Diana Flores Huerta (2015)
Age and depositional environment of the “dinosaur graveyard” at Las
Águilas, southern Coahuila, NE Mexico.
Palaeogeography, Palaeoclimatology, Palaeoecology (advance online publication)
doi:10.1016/j.palaeo.2015.10.020
http://www.sciencedirect.com/science/article/pii/S0031018215005829
Highlights
The number of vertebrate remains at Las Águilas is unique for Central America.
Dinosaur taxa contain Hadrosauridae, Theropoda, Pterosauria, Plesio-
and Mosasauria.
Dinosaurs occur in at least 9 different levels of a 50 m thick deltaic
succession.
Marine, brackish and freshwater fossils reflect cyclic facies oscillations.
Sr isotope ratios provide the first absolute age of 73 ± 1 Ma for the area.
Abstract
Here we provide a detailed description of the upper Campanian sediment
succession at Las Águilas, southern Coahuila, northeastern Mexico,
including the first absolute age dating for this interval,
paleoenvironmental reconstructions and taphonomic observations on the
abundant dinosaur remains at the locality. Stratigraphic
investigations of the dinosaur-bearing succession at the Las Águilas
vertebrate fossil area near Porvenir de Jalpa reveal a diverse
vertebrate assemblage, including dinosaurs, crocodilians and turtles.
New findings in adjacent sites include eusuchian crocodylomorphs, four
different kinds of turtles, dromaeosaurids, lambeosaurines, pterosaurs
and elasmosaurid plesiosaurs. Strontium isotope measurements on fossil
oyster shells provide an absolute age of 73 ± 1 Ma for the lower part
of the Las Águilas section. The locality is thus of late Campanian
age. The vertebrate, invertebrate and plant material as well as the
sediment structures observed in a 50 m thick predominantly
siliciclastic succession of the Cerro del Pueblo Formation suggest
deposition in an extensive delta plain environment. The facies
succession indicates a short-termed cyclicity of limnic, brackish and
shallow marine environments during the late Campanian–early
Maastrichtian Cerro del Pueblo Formation with numerous layers
containing dinosaur fossil remains.