Megalosaurus, whose name translates to “great lizard,” was one of the very first dinosaurs ever formally described. This large, bipedal theropod was a predator, characterized by a long, powerful skull and sharp, serrated teeth designed for tearing flesh. As a member of the Megalosauridae family, it was a large, meat-eating dinosaur walking on strong hind legs. Understanding where this animal lived requires looking to the deeply transformed world of the mid-Mesozoic Era.
The Original Discovery and Type Locality
Megalosaurus was discovered in England, specifically at the Stonesfield Slate quarries near Woodstock in Oxfordshire, which serves as the type locality for the species. The earliest fossil evidence was a partial lower jawbone, along with vertebrae and limb fragments, recovered from the Taynton Limestone Formation. Geologist William Buckland formally named and described the animal in 1824, making Megalosaurus the first genus of non-avian dinosaur to be validly named by scientists.
The remains had been known for much longer; a fragment of a femur was even illustrated in 1677, long before the concept of a “dinosaur” existed. Because the type specimen is a collection of fragmentary bones from the Stonesfield location, this small area of Oxfordshire represents the only certain source of Megalosaurus fossils. All other remains assigned to the genus outside of the late Middle Jurassic rocks of southern England are now generally considered dubious or belong to other species.
The Middle Jurassic World and Paleogeography
The time when Megalosaurus roamed the Earth, approximately 166 million years ago during the Bathonian stage of the Middle Jurassic period, looked drastically different from today. The supercontinent Pangaea was in the process of breaking apart, causing the European landmass to be far from the solid continent we recognize now. At this time, the area that would eventually become Europe was a series of low-lying islands and peninsulas that formed a sprawling archipelago.
These landforms were separated by warm, shallow epicontinental seas that periodically advanced and retreated across the region. The geography resulted in a fragmented distribution for many terrestrial animals, confining the known range of Megalosaurus to this particular island chain. This ancient landscape was part of the larger northern landmass known as Laurasia, but the physical isolation of the islands likely played a part in the distinct evolution of the local fauna.
The Specific Environment and Ecosystem
The islands where Megalosaurus lived enjoyed a subtropical climate, characterized by warm temperatures and high humidity. The landscape consisted of coastal plains, lagoons, and forested regions that provided ample habitat for terrestrial life. The local flora was dominated by ancient plant groups, including ferns, cycads, and tall conifers, which formed the base of the food chain.
Megalosaurus was the apex predator of this localized ecosystem, hunting other terrestrial dinosaurs such as the sauropod Cetiosaurus and the smaller tyrannosauroid Proceratosaurus. Its fossils are often found near marine deposits, suggesting that the predator also scavenged the shores. This scavenging behavior likely included feeding on the remains of marine reptiles, such as plesiosaurs, that washed up from the shallow seas surrounding the islands.