Megalosaurus

Megalosaurus Temporal range: Middle Jurassic, 165 Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓
Fossil specimens referred to M. bucklandii, Oxford University Museum of Natural History. The display shows most of the original syntype series, including the lectotype dentary, identified by Buckland in 1824
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Clade:	Dinosauria
Clade:	Saurischia
Clade:	Theropoda
Family:	†Megalosauridae
Subfamily:	†Megalosaurinae
Genus:	†Megalosaurus Buckland, 1824
Species:	†M. bucklandii
Binomial name
Megalosaurus bucklandii Mantell, 1827
Synonyms
Genus Synonymy Gressylosaurus Lapparent, 1967 Megalasaurus von Huene, 1926 (lapsus calami) Megalosaurns von Huene, 1926 (lapsus calami) Megalosaurus Parkinson, 1822 (nomen nudum?) Megalosausus von Huene, 1926 (lapsus calami) Megalousaurus Ameghino, 1913 (lapsus calami) Megolosaurus von Huene, 1926 (lapsus calami) Meqalosaurus Walker, 1964 (lapsus calami) Scrotum Brookes, 1763 (nomen oblitum) Species Synonymy Megalosaurus bucklandi Mantell, 1827 Megalosaurus conybeari Ritgen, 1826 (nomen oblitum) Scrotum humanum Brookes, 1763 (nomen oblitum)

Megalosaurus was a large meat-eating theropod dinosaur of the Middle Jurassic of Europe. It was found in 1824, and was the earliest dinosaur named. In 1827, Gideon Mantell included Megalosaurus in his geological survey of southeastern England. He gave the species its name, Megalosaurus bucklandii.^[1]

Because a complete skeleton of it has never been found, much is still unclear about its build. The first naturalists who investigated Megalosaurus thought it was a gigantic lizard of twenty metres length. In 1842 Richard Owen concluded that it was no longer than nine metres, standing on upright legs as a quadruped.

Later it was realised that all theropods were bipedal. Today is known that the early proto-dinosaurs in the late Middle Triassic were also bipedal. Certainly Eoraptor, from 231.4 million years ago, was bipedal.^[2] That means the dinosaurs were bipedal from the start (primatively bipedal). Only the heavier sauropods and armoured dinosaurs became quadrupedal, standing on all four legs.^[3]

1. ↑ Mantell G. 1827. Illustrations of the geology of Sussex: a general view of the geological relations of the southeastern part of England, with figures and descriptions of the fossils of Tilgate Forest.
2. ↑ Sereno P.C. et al 1993 Primitive dinosaur skeleton from Argentina and the early evolution of Dinosauria (1993). "Primitive dinosaur skeleton from Argentina and the early evolution of Dinosauria". Nature. 361 (6407): 64–66. Bibcode:1993Natur.361...64S. doi:10.1038/361064a0. S2CID 4270484.{{cite journal}}: CS1 maint: numeric names: authors list (link)
3. ↑ Sereno PC (1999). "The evolution of dinosaurs". Science. 284 (5423): 2137–2147. doi:10.1126/science.284.5423.2137. PMID 10381873.