K-T Extinction
razib | May 6, 2009There are two posts on ScienceBlogs which highlight two perspectives on the Dinosaur mass extinction, What Wiped Out The Dinosaurs? and K-T extinction debates: cranky "skeptics" or reasonable science?. I'd assumed that the Asteroids-from-the-sky was the clear consensus, but please see this old BloggingHeads.TV clip where Peter Ward seems to imply that the waters are muddier than you'd think:
razib | April 29, 2009New Geochronologic And Stratigraphic Evidence Confirms The Paleocene Age Of the Dinosaur-Bearing Ojo Alamo Sandstone And Animas Formation In The San Juan Basin, New Mexico and Colorado:
...An assemblage of 34 skeletal elements from a single hadrosaur, found in the Ojo Alamo Sandstone in the southern San Juan Basin, provided conclusive evidence that this assemblage could not have been reworked from underlying Cretaceous strata. In addition, geochemical studies of 15 vertebrate bones from the Paleocene Ojo Alamo Sandstone and 15 bone samples from the underlying Kirtland Formation of Late…