The_Cretaceous_Extinction

The Cretaceous Extinction The Cretaceous Extinction There are many therioes and ideas on what caused the Cretaceous extinction but I’m going to focus more on the asteriod theory. Some therioes include: volcanic activity, an exploding supernova, and starvation etc. and I will cover them but mainly on the asteriod theory. The reason is because the asteriod theory is the most common and in my opinion one of the most logical. It’s still a tough decision but hopefully in the future we will eventually discover what caused the extinction. About 65 million years ago, at the end of the Cretaceous period, a large fraction of plant and animal families suddenly went extinct. In this Cretaceous-Tertiary or K-T mass extinction (K is for Kreide, meaning chalk in German, which describes the chalky sediment layer from that time. T is for Tertiary which was the next geologic period), all land animals over about 55 pounds went extinct. Later on the smaller organisms began to fade away too. Leading up to the mass extinction, most of the dinosaurs went extinct before the mass extinction at the end of the Cretaceous period. This catatrosphic event led to the Age of Mammals. There are a lot of theories about why cretaceous, extinction, k-t, layer, impact, crater, theory, period, been, quartz, miles, found, km, iridium, earth, about, years, under, tektites, result, organisms, million, mass, high, end, earth's, changes, caused, boundary, because, asteroid, ago, 65, volcanic, shocked, probably