Triassic Period Jurassic Period

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years during the Mesozoic Era, which is divided into three distinct periods: the. Triassic (251–206 million years ago), the. Jurassic (206–145 million years ago),.

Jurassic Period Triassic Period (206–145 million years ago)

(246–206 million years ago)

Dinosaurs flourished for 181 million years during the Mesozoic Era, which is divided into three distinct periods: the Triassic (251–206 million years ago), the Jurassic (206–145 million years ago), and the Cretaceous (145–66 million years ago). The chronologically-distinct exhibits of Dinosaurs in Their Time realistically recreate seven environments spanning the Age of Reptiles, juxtaposing dinosaurs with the creatures who shared their environments, including amphibians, reptiles, fish, birds, and mammals.

The limestone of the Jura Mountains of western Europe (located between France and Switzerland), whose rock formations represent this period of geologic time, lends the Jurassic its name. This stone formed from sediment that accumulated in the shallow seas that covered the area during the Jurassic and includes an abundance of marine animal fossils. Although some forms of life became extinct at the end of the Triassic, the diversity of plants and animals had recovered by the middle of the Jurassic. Dinosaurs came into their own, dominating terrestrial environments and growing larger and more diverse. Mammals thrived, albeit in the shadows, and the airways became increasingly busy as more and more flying reptiles (pterosaurs) evolved and diversified to fill different ecological niches. In late Jurassic times, these pterosaurs were joined by dinosaurs that had feathers, and some of these could fly—birds were beginning to evolve. From early Jurassic times, large reefs were re-established in the shallow seas. Phytoplankton, the microscopic, plant-like organisms that still form the basis of most food chains, enjoyed a new lease on life with the evolution of many of the groups that still dominate the microlife of the oceans today—dinoflagellates and nanoplankton. By the end of the period, bony fishes, or teleosts, had become increasingly similar in appearance to the fish we are familiar with today. They were hunted down by the spectacular “sea monsters” of the Jurassic seas, the predatory ichthyosaurs (fishlizards) and plesiosaurs (near-lizards).

Dinosaurs: Camarasaurus Ceratosaurus Dryosaurus Camptosaurus Stegosaurus Diplodocus Allosaurus Apatosaurus

Heavier than any bear, big cat, or other modern carnivore and armed with sharp fangs and claws, Ceratosaurus was one of the Late Jurassic’s most dangerous predators.

Plants: Conifers Cycads Jurassic Seaway: Lytoceras Ichthyosaurus Dapedium Pholidophorus Tetragonolepis Ptycholepis Lepidotes Pachycormus Redfieldius Semionotus Crocodiles: Steneosaurus Hoplosuchus Goniopholis

Although it looked like a fish, Ichthyosaurus was actually a reptile.

Pterosaurs: Campylognathoides Pterodactulus Mammals: Boreogomphodon Fruitafossor

Most likely, Diplodocus could not lift its long, stiff neck much higher then its shoulders. Instead of browsing on high, leafy twigs, it would have grazed on low-growing ferns, swinging its neck from side to side, stripping the fronds with its peg-shaped teeth.

www.CarnegieMNH.org