Eric Walker added Paleozoic - Wikipedia to Paleozoic era

Eric Walker added Permian-Triassic mass extinction and Permian Period to Permian, and added Permian to Paleozoic era

Eric Walker added a number of topics and Paleozoic - Wikipedia to Paleozoic era, and added Paleozoic era to Phanerozoic

Eric Walker added Ordovician-Silurian extinction events and Silurian - Wikipedia to Silurian period, and added Silurian period to Paleozoic era

Eric Walker added Ordovician-Silurian extinction events and a number of links to Ordovician period, and added Ordovician period to Paleozoic era

Eric Walker added Paleozoic era, Cenozoic and Mesozoic and Phanerozoic - Wikipedia and Cenozoic - Wikipedia to Phanerozoic, and added Phanerozoic to Geologic time scale (GTS)

Eric Walker added Finding a Home on the Tree of Life for a Tentacled Ice Cream Cone With a Lid - The New York Times and They Put the Bite in Trilobite - The New York Times to Cambrian period, and added Cambrian period to Paleozoic era