Best Ordovician

Neoasaphus kowalewskii is a fossil trilobite discovered in Russia’s Ordovician deposits. This species is notable for its exceptionally long stalks supporting its eyes, a unique feature among trilobites. Its stalked-eyes provide valuable insight into the sensory capabilities of asaphid arthropods dur...

An Ordovician trilobite from Bohemia and Iberia notable for its exceptionally large, forward-facing eyes, interpreted as an adaptation to low-light deep-water environments.

Scotoharpes is an Ordovician harpetid trilobite genus with a broad pitted cephalic fringe, fossils of which are found in Scotland.

Cryptolithus is an Ordovician trilobite genus famous for its broad perforated cephalic fringe nicknamed the lace collar, commonly found in North America and Europe.

A large Ordovician trilobite from North America; Isotelus rex from Manitoba, Canada, ranks among the largest trilobites known, and the genus is Ohio's state fossil.

A Silurian cheirurid trilobite recognized by its dramatically inflated, globose glabella, found in Silurian carbonates of Europe and North America.

Charles Lapworth was an English geologist who resolved the Ordovician-Silurian boundary dispute in 1879 by defining the new Ordovician geological period based on graptolites.

Lockne is a marine-target meteorite impact crater in Sweden, notable for its complex structure and formation approximately 455 million years ago during the Middle Ordovician period.

Brent is a meteorite impact crater located in Ontario, Canada, notable for its well-preserved central uplift and its historical use as a lunar astronaut training site.

The Kentland impact crater in Indiana, United States, is notable for its large-scale shatter cones and a deeply quarried central uplift exposing Ordovician and Silurian rocks.

Kardla is a meteorite impact crater located in Estonia, notable for its age of roughly 455 million years and a buried structure that measures four kilometers wide.

Söderfjärden is a meteorite impact crater in Finland, notable for its distinct hexagonal shape, 6-kilometer diameter, and formation roughly 510 million years ago in the Cambrian period.

Ile Rouleau is a meteorite impact crater in Quebec, Canada, notable for its central peak that rises sharply from the waters of Lac Mistassini to form an island.

Wells Creek is a meteorite impact crater in Tennessee, United States, notable for its 8-kilometer diameter and central uplift structure that reveals heavily deformed bedrock.

Granby is a well-preserved meteorite impact crater in Sweden, notable for its 3-kilometer diameter and its formation roughly 470 million years ago during the Middle Ordovician period.

Tvären is a meteorite impact crater in Sweden notable for forming a circular bay in the Baltic Sea, with an estimated diameter of 2 kilometers and an age of roughly 460 million years.

Holleford is a buried meteorite impact crater in Ontario, Canada, notable for its geological identification in the 1950s through magnetic and gravity surveys.

Rock Elm is a meteorite impact crater in Wisconsin, United States, notable for its Ordovician age and distinct circular topographic depression spanning 6.5 kilometers.

Newporte is a buried meteorite impact crater located in North Dakota, United States, notable for its precise discovery through seismic profiling and approximately 3-kilometer diameter.

Glover Bluff, or the Glover Bluff structure, is a highly eroded meteorite impact crater in Wisconsin, United States, notable for its extensive breccia deposits and central uplift.

Des Plaines is a buried meteorite impact crater in Illinois, United States, notable for being discovered through geophysical surveys and its roughly 5-kilometer diameter.