The earliest known vertebrates (Arandaspida) show that by early Ordovician times vertebrate life had already developed complex body armour.
The Taconic orogeny near the end of Ordovician time formed a high mountainous area east of West Virginia.
Together, these three units represent a sequence of sea-level rise during Ordovician time.
Radiolaria have left a geological record since at least the Ordovician times, and their mineral fossil skeletons can be tracked across the K-Pg boundary.
In late Cambrian and early Ordovician times something was still clearly happening along the Atlantic line.
In mid Ordovician times a volcanic island arc is thought to have extended through the English Lake District, Wales and Newfoundland.
Related forms are spread over much of the world in Ordovician and Silurian times.
Burgess polychaetes have no jaws, but jaws evolved by Ordovician times and have persisted ever since.
The canyon and cliff faces show the geologic history of the park stretching from the Ordovician times (570 million years ago) to the Permian times (300 million years ago).
Together, these three formations that are visible as one walks from the upper falls to the river represent a sequence of sea-level rise during Ordovician time.
