Search results for "Silurian" /o "Silurian" - New World Encyclopedia

| fossil_range = Late Silurian – Recent | image = Herring2.jpg ... dating back 420 million years (Late Silurian). This microvertebrate has ...

they are: the Cambrian, Ordovician, Silurian, Devonian, Carboniferous ... between the Ordovician and the following Silurian Period. ...

calcareous shales of the Ordovician and Silurian periods, and often form ... Rugose corals became dominant by the middle of the Silurian period ...

Tertiary, Permian-Triassic, and Ordovician-Silurian extinction events; however, it is unclear to what degree these changes caused the extinctions rather ...

epochs such as the Cambrian, the Silurian, the Devonian, and the Permian. By the early 1840s, much of the geologic timescale had taken shape ...

found in many fossil records, including marine Silurian deposits, coal deposits from the Carboniferous, and in amber. They are thought to have existed ...