The Triassic from the Dinosaur Collector
The Mesozoic starts in the Early Triassic 248 million years ago. The Early Triassic is dominated by the plants and animals that had survived the Late Permian extinction. The Middle Triassic is a period of transition as dicynodonts and cynodonts whose ancestors dominated the Late Permian decline and archosaurs the ancestors of dinosaurs and crocodiles experiment with a variety of plant eating and carnivorous forms. Archosaurus become the leading predators by the Middle Triassic. Dinosaurs do not show up until the Late Triassic with the start of the cycadoid conifer flora that replaces the remaining Paleozoic flora. The world continent Pangaea was still intact without major impediments to movement of animals population. The climate was characterized by extreme aridity alternating with megamonsoons. Prosauropods and small ceratosaurs being the best known dinosaurs but there are lots of other interesting creatures. The last of the archosaurs and dicynodonts die out in the final extinction at the end of the Triassic leaving the dinosaurs to fill the the world. The best information about the Triassic Dinosaurs comes from South America with Argentina producing most of the early finds. Eoraptor is considered the most primitive dinosaur and close to the ancestor of the whole family. Pisanosaurus the earliest known ornithiscian also is from South America. In Europe Triassic finds are scrappy. In Africa, Madagascar has produced interesting finds. The earliest known prosauropods have been reported there but have not yet been described. The earliest sauropods, Isanosaurus in Thailand and the current oldest Antetonitrus ingenipes from South Africa show up in the Triassic. Some combination of climate and flora seems to have favored the prosauropods until the end of the Early Jurassic. Sauropods don't take off until the Middle Jurassic when climate and plants change. At the end of the Triassic an arid climate with low oxygen may have favored confiers. High CO2 can cause rapid growth but reduces the food value in trees. BBC produced Walking with Dinosaurs with a an excellent graphics the Triassic installment was called the New Blood. The Triassic Seas were a time of great change as the great families of aquatic reptiles evolved. During this time the modern sea fauna is established.
