Triassic spans 50.5 million years from Permian to Jurassic periods. Earth was dominated by supercontinent Pangaea until its breakup. Pangaea split into Laurasia (north) and Gondwana (south). Global climate was hot and dry, with occasional tropical rainfall
First dinosaur egg fossils discovered in France in 1859. First recognized non-avian dinosaur eggs found in Mongolia in 1923. Eggshells can be studied under microscope and analyzed using CAT scans. Oldest known eggs are from Massospondylus, 190 million years ago
Carboniferous spans 60 million years from Devonian to Permian. Name means "coal-bearing" from Latin, referring to global coal deposits. Period divided into Mississippian and Pennsylvanian in North America
Trilobites were marine arthropods that existed for 270 million years. First appeared in Early Cambrian (521-251.9 Ma). Over 22,000 species have been described. Largest trilobites reached over 70 cm in length
First fish appeared 530 million years ago during Cambrian explosion. Haikouichthys and Myllokunmingia were first jawless fish. Conodonts and ostracoderms appeared in late Cambrian. Most jawless fish are extinct, except lampreys
Jurassic spans 201.4-145 million years ago, named after Jura Mountains. Pangaea broke into Laurasia and Gondwana during Early Jurassic. Climate was warmer than present, with no ice caps. Sea levels reached peak of 140 meters during Kimmeridgian-Tithonian