Is the following information I gathered about the Cretaceous extinction accurate?

Now, about the Cretaceous mass extinction of the dinosaurs. Virtually no large land animals survived. Plants were also greatly affected while tropical marine life was decimated. Global temperature was 6 to 14°C warmer than present with sea levels over 300 meters higher than current levels. At this time, the oceans flooded up to 40% of the continents. Death was everywhere. This event is marked by a boundary called the K-T Layer or the Cretaceous-Tertiary boundary. I know it should be C-T Layer, but I am not a scientist and didn’t name the thing.  Actually, the “K” is short for kreide, the German word for chalk because vast amounts of chalk were formed during the end of the Cretaceous. This K-T layer thing has been found in both marine and terrestrial sediments and at numerous boundary sites around the world. Many believe that a huge meteor hit near the Yucatan peninsula.