The Triassic Period 248 - 208 Million Years Ago
Homepage > Age of the Dinosaurs - Triassic Period
The Triassic Period (about 248 - 208 million years ago) was the first phase of the Mesozoic era (Age of the Middle Life), often called the Age of Dinosaurs. The Earth was a huge super continent called Pangaea ("all Earth"), of which the northern part was called Laurasia and the southern part Gondwana. It had three main environments and was also dominated by prehistoric reptiles suited to dry conditions. Reptiles also took to the air and seas. In the Late Triassic, many of the older reptiles were wiped out, but new kinds took their place. The most successful of these proved to be the dinosaurs.
The Coast Regions
Forests of giant horsetail ferns, tree ferns and ginkgo trees were alive with insects, amphibians, small reptiles, and early mammals.
The Center of Pangaea
Covered by hot, sandy deserts. Cool areas near the equator had forests of tall conifers and palm like cycads.
Laurasia comprised North America, Europe and Asia. Gondwana included Africa, Arabia, India, Australia, Antarctica, and South America. The south pole was located over the ocean. Pangaea was slowly drifting north as one big land mass. This super continent began to show sings of a future breakup after the Middle Triassic, when cracks appeared in parts of eastern North America, west and central Europe, and northwest Africa.
The type of plants that flourished in Laurasia were those that were adapted to dry climates, such as ginkgoes, seed ferns, and palm like cycads and cycadeoids. The biggest trees of this period were conifers. Ginkgoes formed a fairly open canopy of medium size trees, and cycaids ranged from short, squat forms to taller, palm like species.
The ferns created the under story un the forests, and low ferns formed savannas in drier open areas that would be grasslands today. Close to the equator and in drier regions, patchy conifer and cycad forests thrived. Tall seed ferns formed forests in Gondwana. Later in the Triassic Period ferns were replaced by cycadeoids and conifers.
Reptiles ruled the land during the Triassic Period. Plant eaters included dicynodonts, squat, pig like rhynchosaurs, and cynodonts. There were flesh eating cynodonts as well. Dicynodonts, rhynchosaurs, and most cynodonts died out in the first of the two mysterious mass extinctions.
The thecodonts that largely took their place died out in the second of those extinctions. Survivors included turtles, land crocodilians,dinosaurs, and small mammals. Both of the main dinosaur groups emerged during the late Triassic.
Among saurischian dinosaurs were bipedal flesh eating theropods and quadruped prosauropods. Early ornithischians were small, bipedal herbivores. With no sea to stop them, dinosaurs quickly colonized the world.
Life in the Air
Small reptiles with wings of skin or scales took gliding flights rom tree to tree. These wings were supported by long ribs, or they may simply have been feathery scales growing from arms and legs or webs of skin between front and hind limbs. Late Triassic animals like these may have given rise to furry bodied, warm blooded reptiles called pterosaurs. These creatures had large heads, short bodies, and long skin wings supported by fourth finger bones. This type of creature was capable of powered flight, unlike their gliding ancestors.
Life in the Water
Several reptile groups invaded the Triassic seas. Sharp toothed, fish eating nothosaurus grew up to 13 feet (4 meters) long and had small heads, long tails and bodies, and paddle like limbs. Seal like placodonts crushed shellfish between broad, flat back teeth. Ichthyosaurs, up to about 50 feet (15 meters) long, were the reptiles best adapted to the sea. Among their prey were the big mollusks called ammonoids.
Carnian (228-217 MYA)
The lowermost stage of the Late Triassic System, represented worldwide by deposited rocks. Named after the Carnic Alps in Europe were it was first studied by Mojsisovics in 1869. West Gondwanaland (now South America) is apparently the cradle of the dinosaurs (Eoraptor, Staurikosaurus).