earlyOrdovician

The Early Ordovician is the first of three series, or sub-periods, in the Ordovician Period of the Paleozoic Era. It spans from approximately 488.3 million years ago to 471.7 million years ago. This period is characterized by significant geological and biological changes, marking a critical time in Earth's history.

The Early Ordovician is notable for the Great Ordovician Biodiversification Event, which saw a rapid increase in marine biodiversity. This event is often referred to as the "Cambrian explosion" of the Ordovician. The fossil record from this time shows a diverse array of marine life, including the first appearance of many modern phyla.

Geologically, the Early Ordovician is marked by the deposition of extensive carbonate platforms and the beginning of the Taconic orogeny, a mountain-building event that affected the eastern margin of the North American continent. The climate during this period was generally warm and humid, with evidence suggesting the presence of extensive tropical seas.

The Early Ordovician is followed by the Middle Ordovician, which is characterized by the deposition of the Trenton Limestone and the expansion of carbonate platforms. The period ends with the Hirnantian glaciation, a significant ice age that occurred near the end of the Ordovician Period. This glaciation is believed to have contributed to the subsequent mass extinction event at the end of the Ordovician.