CTgeo

Other animals, plants, rocks, and ecology


    The great mural in the exhibit center by William Sillin, called "In the Late Triassic," spans 30 feet along the south wall of the main room.  The mural depicts the landscape of the Connecticut Valley at the end of the Triassic Period about 201 million years ago.  This was a time shortly before the mass extinction of about half of all species on Earth, and also before the enormous volcanic lava flows called flood basalts that covered much of eastern North America.  Both of these catastrophes mark the end of Triassic time and the start of the Jurassic Period.  This image of the Sillin Mural has "hot links" for many of the objects in the mural, which you can click to bring up names for the objects at the bottom of the page.

    In front of the Sillin Mural is a diorama that appears to flow out of the painting. Life-size models of Rutiodon (a crocodile-like reptile) and Metoposaurus (a large amphibian with teeth) are surrounded by tree ferns, cycads, horsetails, and club moss plants.  There is fossil evidence for all of these along Connecticut river banks at the end of the Triassic Period.

    Other exhibits at Dinosaur State Park show you fossils and models of the fish (Semionotus) that were abundant in lakes in the Connecticut Valley, and there are wonderful murals and models of other reptiles that flew (a pterosaur called Dimorphodon), swam (crocodile-like reptiles called Rutiodon) and crawled (lizard-like reptiles called Antipus).  Insects were abundant and included large dragonflies, roaches, and beetles.  The lakes were sometimes large and deep, and in other times were about dried up, leaving  alternating sandstone and mud layers that became sedimentary rocks of the East Berlin formation.  It was much warmer than today, something more like Africa's climate, and probably there were separate dry and wet (monsoon) seasons.  Forests of gingko and conifer (gymnosperm) trees were present as well as ferns, reeds, horsetails, and palm-like cycad bushes, and wetland animals like turtles, frogs, and bigger amphibians.  In the undergrowth beneath the towering conifer forest, small plant-eating ornithischian dinosaurs called Anchisaurus browsed on the shrubs and leaves.  At that time, there were no grasses, gymnosperm (flowering) plants and trees, and no birds, butterflies, bees, or ants.  Many of these modern types did appear later in the Mesozoic Era, but rocks and fossils younger than 180 million years old are not preserved in Connecticut.