List contains over 700 dinosaurs from Triassic, Jurassic, and Cretaceous periods. Includes well-known dinosaurs like T. Rex and Triceratops. New discoveries continue to uncover previously unknown dinosaurs
Mesozoic Era spans 250-65 million years ago. Geologists mark dinosaur periods based on fossil locations. Earth was joined into Pangaea during Triassic period
Argentinosaurus was discovered in 1987 near Plaza Huincul, Argentina. Named by Bonaparte and Coria in 1993 as "Argentine lizard". Only fragmentary remains known, including complete femur and fibula. Estimated length of 30-35 meters and weight of 65-80 tonnes
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
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 Velociraptor fossil found in Mongolia in 1923. Two known species: Velociraptor mongoliensis and Velociraptor osmolskae