For 10 points, name these events that have resulted in many organisms dying out.
Raup and Sepkoski studied the periodic nature of these events. A multi-component explanation of the largest of these events was dubbed by Douglas Erwin the Murder on the Orient Express hypothesis. Ones named for Ireviken, Mulde, and Lau occurred during the Silurian period. Evidence for the cause of one of these events includes high levels of iridium and the Chicxulub [CHIK-shoo-loob] crater. Another of these events that may have been caused by the eruption of the Siberian traps occurred at the boundary between the Permian and Triassic periods. For 10 points, name these events that have resulted in many organisms dying out.
Raup and Sepkoski studied the periodic nature of these events.
extinction events [or equivalents, such as mass extinctions] 