MEANING: Great lizard
PERIOD: Middle Jurassic
CONTINENT: Europe
Megalosaurus was the first genus of non-avian dinosaur to be validly named, and it played a pivotal role in scientific understanding of prehistoric life. Megalosaurus was among the largest of Middle Jurassic theropods, though the exact size is difficult to determine due to a lack of vertebral remains. It is estimated between 6-9 m in length and it probably weighed around 1 t. The original specimen, along with Iguanodon and Hylaeosaurus defined what is considered a “dinosaur” to this day.
Megalosaurus is from the Jurassic. The Jurassic is a geologic period that spanned from the end of the Triassic, 201 million y ears ago, to the beginning of the Cretaceous, 145 million years ago. It is the middle period of the Mesozoic Era. The start of the Jurassic was marked by the major Triassic-Jurassic extinction event. The end, however, has no clear boundary with the Cretaceous. By the beginning of the Jurassic, Pangea had begun rifting into two landmasses: Laurasia and Gondwana, and the climate was warm with no ice caps. Life on land was dominated by dinosaurs, and the first birds appeared, evolving from a branch of theropods. The oceans were inhabited by marine reptiles, while pterosaurs were the dominant flying vertebrates.
Megalosaurus is a theropod. Theropods are dinosaurs that are characterized by hollow bones and three toes and claws on each limb. Theropods are generally classed as a group of saurischian dinosaurs. They were ancestrally carnivorous, although a number of theropod groups evolved to become herbivores and omnivores. Theropods first appeared during the Carnian age of the late Triassic period and included all the large terrestrial carnivores from the Early Jurassic until at least the close of the Cretaceous. In the Jurassic, birds evolved from small specialized theropods, and are today represented by about 10,500 living species.