(2007) suggest that a member of the Baptistina asteroid family was the probable source of the K/T impactor which ended the reign of the Di-nosaurs 65 Myr ago. These fossils lend further support to the hypothesis that a diverse terrestrial fauna, dominated by dinosaurs and crocodylomorphs but also including turtles, was widespread across South America (and possibly Gondwana) during the very end of the Cretaceous Period. Despite the fragmentary condition of the new fossils, they demonstrate that the local fauna was diverse during the latest Cretaceous, and generally similar to Bauru Group faunas from other parts of Brazil. As previous records from this region were limited to a single indeterminate sauropod bone, these new fossils are the first diagnostic members of their groups from southern Goiás State. Although these fossils are isolated and largely incomplete, they record a high diversity of vertebrates, including podocnemidoid turtles, crocodyliforms, and titanosaurid dinosaurs. Here we describe a fossil reptile assemblage from the Late Cretaceous of the Adamantina and Marília formations (Bauru Group, Paraná Basin) in a region that has gone largely unexplored: southern Goiás State. Most of these records, however, come from a few regions, most notably Mato Grosso, western São Paulo, and Triângulo Mineiro. But this worst single day in the history of life on Earth was as critical for us as it was for the dinosaurs, as it allowed for evolutionary opportunities that were closed for the previous 100 million years.Over the past few decades, important fossils of dinosaurs, crocodylomorphs, and other latest Cretaceous vertebrates have been recovered from the Bauru Group of Brazil, giving unique insight into how Gondwanan faunas were evolving before the end-Cretaceous asteroid impact. In the terrible mass extinction that followed, more than half of known species vanished seemingly overnight. An asteroid some seven miles across slammed into the Earth, leaving a geologic wound over 50 miles in diameter. The cause of this disaster was identified decades ago. Tyrannosaurus rex will be toppled from their throne, along with every other species of non-avian dinosaur no matter their size, diet, or disposition. In a matter of hours, everything here will be wiped away. A Triceratops horridus ambles along the edge of the forest. It's a sunny afternoon in the Hell Creek of ancient Montana 66 million years ago.
Picture yourself in the Cretaceous period. Life's losses were sharp and deeply-felt, but the hope carried by the beings that survived sets the stage for the world as we know it now. In The Last Days of the Dinosaurs, Riley Black walks readers through what happened in the days, the years, the centuries, and the million years after the impact, tracking the sweeping disruptions that overtook this one spot, and imagining what might have been happening elsewhere on the globe.
0 kommentar(er)
