Does the plankton record agree that a meteor caused the Cretaceous/Tertiary mass extinction?
Almost all the large vertebrates on Earth, on land, at sea, and in the air (all dinosaurs, plesiosaurs, mosasaurs, and pterosaurs) suddenly became extinct about 65 Ma, at the end of the Cretaceous Period. At the same time, most plankton and many tropical invertebrates, especially reef-dwellers, became extinct, and many land plants were severely affected. This extinction event marks a major boundary in Earth’s history, the K-T or Cretaceous-Tertiary boundary, and the end of the Mesozoic Era. The K-T extinctions were worldwide, affecting all the major continents and oceans. There are still arguments about just how short the event was. It was certainly sudden in geological terms and may have been catastrophic by anyone’s standards. Despite the scale of the extinctions, however, we must not be trapped into thinking that the K-T boundary marked a disaster for all living things. Most groups of organisms survived. Insects, mammals, birds, and flowering plants on land, and fishes, corals, and
The plankton record doesn’t lie. And again it is showing that the meteor that created the Chicxulub impact crater in Mexico didn’t cause the Cretaceous/Tertiary [KT] mass extinction, says Gerta Keller – the Princeton University paleontologist whose group has been a primary questioner of the widely accepted theory that the asteroid wiped out the dinosaurs and most life 65 million years ago.
