Late Ordovician

• Dauber/Muller - 440 million years ago
• Sagan/Sepkoski - 435 million years ago

Late Devonian

• Sagan/Sepkoski ,Dauber/Muller - 365 million years ago

The Permian-Triassic Extinction

• Dauber/Muller- 250 million years ago
• Raup/Sepkoski - 248 million years ago.
• Sagan/Sepkowski - 245 million years ago

Late Triassic (Norian)

• Sagan/Sepkowski - 220 million years ago
• Raup/Sepkowski - 219 million years ago
• Dauber/Muller - 210 million years ago

The K/T Extinction

• Sagan/Sepkowski,Dauber/Muller - 65 million years ago
• The K/T boundary layer

The Eocene-Oligocene events

• Clube and Napier, 40-44 million years ago
• Raup/Sepkowski,Dauber/Muller - 38 million years ago.
• Sagan/Sepkowski - 35 million years ago

12 million years ago - minor extinction