How Megalosaurus, The First-Ever Dinosaur, Was Discovered And Named 200 Years Ago

Large fossilized bones discovered in Oxfordshire’s slate quarries in the late 1600s posed an immediate mystery in a world unfamiliar with concepts of evolution and extinction. Seeking an explanation, experts speculate they might belong to a Roman war elephant or a colossal human. It wasn’t until 1824 that William Buckland, Oxford University’s inaugural geology professor, identified and named the first dinosaur, using a lower jaw, vertebrae, and limb bones found in those quarries, with the largest thigh bone measuring 2 feet, 9 inches in length and nearly 10 inches in circumference.

Presenting his findings to the Geological Society on February 20, 1824, William Buckland named the creature whose bones were discovered Megalosaurus, translating to “great lizard.” In his scientific paper, Buckland described it as a carnivore, estimating a length exceeding 40 feet (12 meters) and comparable in size to an elephant. Notably, he believed Megalosaurus could be amphibious, inhabiting both land and water. Paleontologist Steve Brusatte commended Buckland’s groundbreaking concept, acknowledging the accuracy of identifying a group of extinct, giant reptilian creatures.

Consider a world without the term “dinosaur,” where the concept is unknown, and you are among the first to grasp this revelation by merely examining a few sizable bones from the ground. Despite the ubiquity of dinosaur imagery, envision a reality where these creatures were yet to be defined or understood.

The term “dinosaur” was coined by anatomist Richard Owen, founder of London’s Natural History Museum, two decades after Buckland’s Megalosaurus discovery. Owen identified shared characteristics in Megalosaurus, along with two other dinosaurs, Iguanodon and Hylaeosaurus, described in 1825 and 1833, respectively. Although Buckland’s Megalosaurus paper solidified his standing in geology, its true significance as the inaugural scientific description of a dinosaur became evident only in hindsight.

In its time, Megalosaurus took a backseat in public fascination to the complete fossils of marine reptiles like the ichthyosaur and plesiosaur, discovered by Mary Anning along England’s Dorset Coast. Despite lacking a complete skeleton, Megalosaurus left its mark on popular culture. Charles Dickens, a friend of Richard Owen, envisioned encountering a Megalosaurus in the muddy streets of London in the opening of his 1852 novel, “Bleak House.” The dinosaur also found a place in London’s Crystal Palace in 1854, part of the world’s first dinosaur park, where it remains today. While the displayed head shape is largely accurate, contemporary knowledge reveals Megalosaurus to be around 6 meters (about 20 feet) long, walking on two legs instead of four.