Latest Cretaceous Stories

There's growing evidence that the dinosaurs and most their contemporaries were not wiped out by the famed Chicxulub meteor impact, according to a paleontologist who says multiple meteor impacts, massive volcanism in India, and climate changes culminated in the end of the Cretaceous Period. The Chicxulub impact may, in fact, have been the lesser and earlier of a series of meteors and volcanic eruptions that pounded life on Earth for more than 500,000 years, say Princeton University...

Ancient rocks from the bottom of the Pacific Ocean suggest dramatic climate changes during the dinosaur-dominated Mesozoic Era, a time once thought to have been monotonously hot and humid. In this month's Geology, scientists from Indiana University Bloomington and the Royal Netherlands Institute for Sea Research present new evidence that ocean surface temperatures varied as much as 6 degrees Celsius (about 11 degrees Fahrenheit) during the Aptian Epoch of the Cretaceous Period 120 million...

The recovery of biodiversity after the end-Cretaceous mass extinction was much more chaotic than previously thought, according to paleontologists. New fossil evidence shows that at certain times and places, plant and insect diversity were severely out of balance, not linked as they are today. The extinction took place 65.5 million years ago. Labeled the K-T extinction, it marks the beginning of the Cenozoic Era and the Paleocene Epoch."The K-T caused major extinction among North American...

Boulder, Colo. - A new study of melted rock ejected far from the Yucatan's Chicxulub impact crater bolsters the idea that the famed impact was too early to have caused the mass extinction that killed the dinosaurs 65 million years ago. A careful geochemical fingerprinting of glass spherules found in multiple layers of sediments from northeast Mexico, Texas, Guatemala, Belize and Haiti all point back to Chicxulub as their source. But the analysis places the impact at about 300,000 years before...

Scientists can recite a long list of the devastating environmental consequences of a large meteorite impact, but they cannot prove these effects have led to the simultaneous loss of life around the globe. Answering the question of how and why such a large variety of species died out at the same time is one of the greatest mysteries in paleontology.Astrobiology Magazine -- At least 50 percent of the world's species, including the dinosaurs, perished 65 million years ago. A large meteorite...

Chicago -- Scientists at the American Museum of Natural History and the University of Chicago have explained how a globe-encircling residue formed in the aftermath of the asteroid impact that triggered the extinction of the dinosaurs. The study, which will be published in the April issue of the journal Geology, draws the most detailed picture yet of the complicated chemistry of the fireball produced in the impact. The residue consists of sand-sized droplets of hot liquid that condensed from...

The devastating cycles of plant and animal extinctions have spawned different schools of thought: Did the earth or the heavens bring catastropher?Astrobiology Magazine -- Two hundred and fifty million years ago, ninety percent of marine species disappeared and life on land suffered greatly during the world's largest mass extinction. The cause of this great dying has baffled scientists for decades, and recent speculations invoke asteroid impacts as a kill mechanism. Yet a new study published...