Megalosaurus

Megalosaurus is a theropod dinosaur of the Jurassic, and the first non-avian dinosaur to be described.

Description
Only a few bones of Megalosaurus have ever been found, namely a lower jaw and fragments of some hind limbs. However, it is now believed that it had a typical theropod shape, and measured about 9 meters long.

Classification
Although Megalosaurus was always believed to be a large carnivorous reptile, it was not considered a dinosaur until 1842, when the name was invented.

Megalosaurus was once used as a wastebasket taxon, and any indeterminate theropod material was usually placed into this genus. In the 20th century it was finally suggested that the name be limited to the fossils found in the original quarry. However, it was then suggested that the bones of Megalosaurus were probably those of several different types of theropod, and that Megalosaurus may not even be a valid genus. In 2008, though, it was shown that the original lower jaw had several apomorphic characteristics that distinguished it from other genera.

History
Part of a femur believed to come from Megalosaurus was uncovered in a limestone quarry in Oxfordshire, in 1676. The bone was sent to Robert Plot, who interpreted it as the end of a femur from a giant human.

The bone was described again in 1763 by Richard Brookes, who named it "Scrotum humanum" due to its apparent resemblance to human testicles. The name was never subsequently used, and the name is considered a nomen oblitum. If it was actually supposed to have represented a new genus, the name would have had priority over Megalosaurus. However, rules of the International Code of Zoological Nomenclature state that if a name is not considered valid after 1899, it is exempt from priority.

In 1815, more discoveries were made in the Stonesfield quarry. Professor William Buckland acquired the bones, and in 1818 identified them as the bones of a giant lizard, with the help of Georges Cuvier. Buckland described the bones in 1824 and gave them the name Megalosaurus. He estimated the animal to be 12 meters long. In 1827, Gideon Mantell gave the species a full name, Megalosaurus bucklandii.

In 1852, Megalosaurus was one of the species chosen to be reconstructed at Crystal Palace Park. However, it was shown to be a lumbering quadruped instead of a biped, as early paleontologists did not have complete skeletons to work off of. It was also portrayed as having a hump, a feature borrowed from the genus Becklespinax.

In 1997, a trackway of footprints thought to be from Megalosaurus was discovered in a quarry northeast of Oxford.

Diet
Megalosaurus was a carnivore, preying on other dinosaurs of the time.

Pathology
Richard Owen examined a rib bone of Megalosaurus that had a swollen spot, which may have been caused by an injury or infection.

In popular culture
Megalosaurus was the first dinosaur to appear in popular culture, in Charles Dickens's 1852 novel Bleak House:

"Implacable November weather. As much mud in the streets as if the waters had but newly retired from the face of the earth, and it would not be wonderful to meet a Megalosaurus, forty feet long or so, waddling like an elephantine lizard up Holborn Hill."

- Bleak House (Charles Dickens)

It also appeared in other forms of media.