Cretaceous-Tertiary extinction event

The Cretaceous-Tertiary (K-T or KT) extinction event, also known as the KT boundary, was a period of massive extinction of species, about 65.5 million years ago. It corresponds to the end of the Cretaceous Period and the beginning of the Tertiary Period. (K is the traditional abbreviation for the Cretaceous period. Cretaceous comes from the Latin for chalk, creta. The K comes from the German word for chalk kreide, or possible Greek kreta. The K is used so as to avoid confusion with the Carboniferous period which uses the letter C.)

References and external links

• Understanding the K-T Boundary - NASA-related website
• Shiva crater: Chatterjee et al. 2002 Volcanism, India-Seychelles Rifting, Dinosaur Extinction, and Petroleum Entrapment at the KT Boundary (GSA abstract)
• list of 172+ impact craters in Earth Impact Database with Crater name, Diameter, Age, Country, Latitude, Longitude, etc.
• Air bubbles, amber, and dinosaurs
• Earth Impact Database
• "The KT Boundary" on Melvyn Bragg's In Our Time on BBC, Radio 4, 23rd June 2005