It marked the first appearance of pachycephalosaurids, and Walter and Luis Alvarez postulated that the concentration of iridium found in a thin layer of sediment, the K-T boundary, was linked to the end of this period.
In this period, subduction of the Kula and Farallon plates under the North American plate contributed to the Laramide orogeny. A series of large volcanic eruptions formed the Deccan Traps at the end of this period. It marked the first appearance of pachycephalosaurids, and Walter and Luis Alvarez postulated that the concentration of iridium found in a thin layer of sediment, the K-T boundary, was linked to the end of this period. Large chalk deposits laid down during this period give it its name. For 10 points, name this final period of the Mesozoic Era, during which a meteor strike is hypothesized to have killed the dinosaurs.
In this period, subduction of the Kula and Farallon plates under the North American plate contributed to the Laramide orogeny.
Cretaceous period