Dinosaur extinction: Scientists estimate 'most accurate' date 8 February 2013 Last updated at 10:10 Scientists believe they have determined the most precise date yet for the extinction of dinosaurs. Researchers from Glasgow University were part of an international team that has been investigating the demise of the dinosaur. By using dating techniques on rock samples, they established the creatures died out about 66,038,000 years ago - give or take 11,000 years. That date coincides with the impact of a comet or asteroid. The scientists' findings have been published in the journal Science. The study also involved researchers from the University of California, Berkeley and Vrije University. The extinction of the dinosaurs was first linked to a comet or asteroid impact in 1980. Final straw A 110-mile-wide crater in the Caribbean off the Yucatan coast of Mexico is presumed to be the result of that impact. Called Chicxulub, the crater is thought to have been excavated by an object six miles across that threw into the atmosphere debris which is still found around the globe as glassy spheres or tektites, shocked quartz and a layer of iridium-enriched dust. The international team decided last year to re-date the dinosaur extinction. They looked at tektites from Haiti to determine how long ago the crater impact occurred, then did the same for altered volcanic ash collected from the Hell Creek Formation in Montana, the source of many dinosaur fossils and one of the best sites to study the change in fossils from before and after the extinction. Paul Renne, professor in residence of earth and planetary science at the University of California, said: "The impact was clearly the final straw that provided the tipping point. We have shown that these events are synchronous to within a gnat's eyebrow and therefore the impact clearly played a major role in extinctions, but it probably wasn't just the impact. The Glasgow researchers, based at the Scottish Universities Environmental Research Centre in East Kilbride and led by Dr Darren Mark, then conducted independent argon-argon analyses on rock samples, which confirmed the results from the US. Dr Mark said: "This study shows the power of high precision geochronology. Many people think precision is just about adding another decimal place to a number, but it's far more exciting than that. It's more like getting a sharper lens on a camera. It allows us to dissect the geological record at greater resolution and piece together the sequence of Earth history.