Ordovician
Travel Back in Time!
Major Geological Events
Warm, shallow seas cover much of Earth
Ice cap covers what is now North Africa
Part of the Paleozoic era, a rich variety of marine life flourished in the vast seas and the first primitive plants began to appear on land
Most of the world's landmasses came together to create the supercontinent of Gondwana, which included the continents of Africa, South America, Antarctica, and Australia
Climate
For the most part the Earth's climate was warm and wet, with sea levels rising as much as 1,970 feet (600 meters) above those of today.
For the most part the Earth's climate was warm and wet, with sea levels rising as much as 1,970 feet (600 meters) above those of today.
This was a sign that a 20-million-year ice age during which shallow, life-rich seas shrank away, was coming.
Trilobites Life was still primarily found underwater, but there were more different species than ever before. The trilobites did not die out with the mass extinction at the end of the Cambrian period. Trilobites lived on and many new species developed. | Cephalopods The Cephalopods animal forms developed, too. The cephalopods became the dominant predators of this period. Cephalopods are a group of mollusks that are related to octopus and squid. | BrachiopodsBrachiopods were also new in the Ordovician period. Brachiopods look like clams, but they do not belong to the same family. A Brachiopod’s shells do not match. If you look closely, one shell is slightly larger at the hinge. The shells themselves each have bilateral symmetry. Clam shells have identical hinges so their shells are not symmetrical. |
Trilobites
Cephalopods
Brachiopods
Brachiopods were also new in the Ordovician period. Brachiopods look like clams, but they do not belong to the same family. A Brachiopod’s shells do not match. If you look closely, one shell is slightly larger at the hinge. The shells themselves each have bilateral symmetry. Clam shells have identical hinges so their shells are not symmetrical.