|Mosasaur vertebra embedded in shelly sandstone with dark ejecta spherules from Chicxulub (See more images with dinosaur tooth)
finds of a dinosaur tooth (here) (?Ornithomimus),
and a Mosasaur vertebra (here)
within tsunami deposits with ejecta of the Chicxulub impact in the
La Popa (near Monterrey, Mexico) basin demonstrate that these reptiles lived
up to the K/T boundary, and have not disappeared before the Chicxulub impact.
tooth and vertebra were lying around on the surface further west in the Parras
basin where more dinosaur remains have been found, and were washed in the
sea by the tsunami backwash.
Regarding their good preservation, the fossils
were likely not buried in the ground, before being back-washed with the
La Popa K/T boundary
|The Popa Basin on Google Earth
|The outcrop of the tsunamites where the vertebrate remains were found