The Ordovician (/ɔːrdəˈvɪʃi.ən, -doʊ-, -ˈvɪʃən/ or-də-VISH-ee-ən, -⁠doh-, -⁠VISH-ən) is a geologic period and system, the second of six periods of the...

Cap Late D O–S The Late Ordovician mass extinction (LOME), sometimes known as the end-Ordovician mass extinction or the Ordovician-Silurian extinction, is...

The Late Ordovician, also called the Upper Ordovician by geologists, is the third epoch of the Ordovician period. At this time Western and Central Europe...

The Early Ordovician is the first epoch of the Ordovician period, corresponding to the Lower Ordovician series of the Ordovician system. It began after...

The Great Ordovician Biodiversification Event (GOBE), was an evolutionary radiation of animal life throughout the Ordovician period, 40 million years after...

geologic period and system spanning 24.6 million years from the end of the Ordovician Period, at 443.8 million years ago (Mya), to the beginning of the Devonian...

subdivided into six geologic periods (from oldest to youngest): Cambrian Ordovician Silurian Devonian Carboniferous Permian Some geological timescales divide...

appearing in the Ordovician include: Cyclopyge (Early to Late Ordovician) Selenopeltis (Early to Late Ordovician) Parabolina (Early Ordovician) Cheirurus (Middle...

Sacabambaspis is an extinct genus of jawless fish that lived in the Ordovician period. Sacabambaspis lived in shallow waters on the continental margins...

Ediacaran period 538.8 Ma (million years ago) to the beginning of the Ordovician Period 485.4 Ma. Most of the continents lay in the southern hemisphere...