Nonmarine fluvial, eolian and lacustrine strata of the Chinle and Glen Canyon groups in northeastern Arizona and adjacent areas preserve tetrapod body fossils and footprints that are one of the world’s most extensive tetrapod fossil records across the Triassic-Jurassic boundary. We organize these tetrapod fossils into five, time-successive biostratigraphic assemblages (in ascending order, Owl R...

Several positive carbon isotope excursions in Lower Paleozoic rocks, including the prominent Upper Cambrian Steptoean Positive Carbon Isotope Excursion (SPICE), are thought to reflect intermittent perturbations in the hydrosphere-biosphere system. Models explaining these secular changes are abundant, but the synchronicity and regional variation of the isotope signals are not well understood. Ex...

Recent discoveries have demonstrated that Revueltosaurus callenderi Hunt is not an ornithischian dinosaur, so it is probably not congeneric with the putative ornithischian Revueltosaurus hunti Heckert. Revueltosaurus Hunt, 1989 is the senior generic name, so I propose here the generic name Krzyzanowskisaurus for “Revueltosaurus” hunti. Because the teeth of K. hunti appear more derived than R. c...

The Upper Cretaceous deposits of northwestern Colombia accumulated in two regions with distinct tectonic settings. eastern deposits, consisting Turonian–Maastrichtian rocks from the Magdalena Valley (UMV) and Cesar-Rancheria basins, were deposited by an epicontinental sea that partially covered South American Plate. In contrast, western which comprise a series highly faulted folded Coniacian–Ma...

Abstract Large-sized cricetid rodents (Cricetodotontini) immigrated to Central Europe at the beginning of Middle Miocene Climate Transition ca. 15 My and are thus great value for biostratigraphic palaeoecologic purposes. An important fossil material belonging a relatively small species Mixocricetodon from North Alpine Foreland Basin is described. It rare component in faunas equivalent age, new ...