Megalosaurus
Megalosaurus is recognized as the first dinosaur species to be formally identified and described in scientific literature. Discovered in the early nineteenth century in Oxford, England, by William Buckland, a Christian minister and fossil hunter, its bones highlighted the reality of extinction at a time when the concept was just emerging. Despite its significance, Megalosaurus remains somewhat enigmatic due to the absence of a complete skeleton. It is classified as a theropod dinosaur, characterized by its stiff tail, three curved claws, and sharp teeth, and is part of a broader group known as Torvosauroidea.
This carnivorous dinosaur likely hunted smaller herbivorous dinosaurs in its warm, humid Jurassic environment, approximately 165 million years ago. While its large head and powerful hind limbs suggest a predatory lifestyle, some evidence indicates it may have occasionally scavenged. Fossilized tracks indicate that Megalosaurus could reach speeds up to 32 kilometers per hour. Due to the historical misclassification of many fossils, scientists today approach Megalosaurus’ taxonomy with caution, emphasizing the need for more definitive finds. Megalosaurus was honored in 2020 when it was featured on a 50 pence coin in the UK, celebrating its place in the country's paleontological history.
Megalosaurus
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Saurischia
Family: Megalosauridae
Genus:Megalosaurus
Species:Megalosaurus bucklandii
Introduction
Megalosaurus is notable for having been the first dinosaur species ever to be found and formally described in the scientific literature as an ancient animal that no longer existed. (Many previously discovered examples of dinosaur bones had been incorrectly interpreted as mythical or legendary creatures.) Megalosaurus hip, leg, and skull bones were uncovered in Oxford, England, in the early nineteenth century by a Christian minister and amateur fossil hunter named William Buckland. The find was a dramatic discovery that came not long after the concept of extinction itself had been proposed by Baron Georges Cuvier, a French zoologist, and several years before the name “dinosaur” had even been coined by paleontologist Richard Owen. Strikingly, however, although it was one of the earliest species to have been studied, Megalosaurus is still somewhat of a mystery, partly because no complete skeleton has ever been discovered.
Classification
For most of the first 200 years after the first Megalosaurus bones were discovered, a huge number of other bones and fossil fragments that seemed to have been from carnivores, but had no other clear identifiable characteristics, were placed within the family Megalosauridae without much thought. This practice bloated the group with many incorrectly labeled dinosaur species (including Dilophosaurus, Carcharodontosaurus, and Majungasaurus), and made it even more difficult for scientists to accurately describe the taxonomy of Megalosaurus itself.
Under the traditional Linnaean classification, which groups dinosaurs according to their shared physical characteristics, Megalosaurus is generally considered to be part of a group of theropod dinosaurs, which have stiff tails, three curved claws on each hand, and sharp teeth. Other members of the theropod group include Afrovenator and Torvosaurus.
A cladistics-based classification, which groups species according to their phylogenetics, or the number of physical traits they share, places Megalosaurus within the clade, or group, Torvosauroidea, which is a sub-clade of Tetanurae (meaning “stiff tails”). This group also includes Spinosaurus, another theropod with powerful back limbs and relatively small forelimbs.
Anatomy
Megalosaurus had the large head, long nose, narrow jaw, and sharp, serrated teeth that were typical of a carnivorous dinosaur. It also had a stocky, muscular neck that was fairly flexible and a fairly large torso, but relatively small forelimbs. The dinosaur's hind limbs, in contrast, were large and powerful. (Megalosaurus is believed to have been a bipedal animal.) In addition, it had a long, thick, tail—also a typical feature of predatory dinosaurs from the theropod group, to which Megalosaurus belonged. Together, these characteristics resulted in an overall body shape not dissimilar to that of another well-known predator, Tyrannosaurus rex, a species that existed some 100 million years later. However, in comparison to Megalosaurus, Tyrannosaurus's front arms were even more reduced in size. Megalosaurus was also significantly skinnier and smaller than the behemoth that was Tyrannosaurus.
Intelligence
Theropods like Megalosaurus had relatively large brain cases for their size, with EQs of up to 2.0, and were therefore probably among the more intelligent and socially complex dinosaurs.
Reproduction and Population
Little evidence in the fossil record relates to the reproductive habits of Megalosaurus. However, discoveries of eggs and nests belonging to related species can help to shed some light on how dinosaurs lived and reproduced. For example, the nests of many carnivorous dinosaurs, such as dromaeosaurids, are typically found singly, with no other nests nearby. Such findings suggest that the species in question lived largely in isolation. This may also have been the case with Megalosaurus.
Diet
Like its fellow tetanurans (from the clade tetanurae), including Allosaurus and Velociraptor, Megalosaurus was a fierce hunter whose carnivorous diet consisted of smaller animals, usually herbivorous herd dinosaurs such as sauropods and stegosaurs. In the past, some scientists speculated that the lack of wear found on the teeth of large theropods, including Megalosaurus and Tyrannosaurus, meant that they might be scavengers, feeding on carrion, rather than hunters tearing apart their own prey. Today, scientists agree that Megalosaurus was certainly a predator first and foremost, but might occasionally have scavenged on carcasses if it happened to come upon them.
Behavior
When racing after its prey, Megalosaurus would have leaned heavily forward, holding its body with its neck and tail both extended in a nearly horizontal position. Based on a fossilized trackway found in a quarry near Oxford, England, in 2002, scientists believe that the animal walked with its toes pointed inward, but when it broke into a run its feet turned outward instead. Also, rather than occasionally lifting both its feet off the ground at the same time, which is the way most animals run, Megalosaurus seems to have simply lengthened its stride in order to travel faster. The tracks also suggest that Megalosaurus may have reached a maximum speed of about 32 kilometers (about 20 miles) per hour and may have been relatively light on its feet despite its large size.
Habitat and Other Life Forms
Megalosaurus was a Jurassic-era dinosaur that lived approximately 165 million years ago in what is now the southern part of England. At that time, the climate in that area was warm and humid, resembling the tropical climate of countries around the equator today. The landscape was covered in dense forests of flowering plants (angiosperms), cycads (palm-like plants), mosses, and conifers, providing ample vegetation for Megalosaurus's herbivorous prey, such as Iguanodon and Cetiosaurus, to feed on.
Research
In contrast to earlier scientific practices, which used the Megalosauridae family as a kind of “dumping ground” for carnivorous species, researchers today are extremely cautious about what they are willing to classify as belonging or being related to the genus Megalosaurus. In fact, according to some very recent analysis, the only bone that can be definitively attributed to Megalosaurus is a single fossil of its lower jaw. As a result, some scientists contend that the entire megalosauridae family ought to be discarded until a more complete Megalosaurus skeleton is found that enables a better comparison between this species and others that are similar to it. In 2020, the United Kingdom paid tribute to its archeological past by depicting the Megalosaurus, as well as two other dinosaurs discovered in Britain, on its 50 pence coin.
Bibliography
Benson, Roger B. J. “A Description of Megalosaurus bucklandii (Dinosauria: Theropoda) from the Bathonian of the UK and the Relationships of Middle Jurassic theropods.” Zoological Journal of the Linnean Society, vol. 158, no. 4, 2010, pp. 882–935.
Farlow, James Orville. Complete Dinosaur. Indiana UP, 2000.
Fastovsky, David E., and David B Weishampel. Dinosaurs: A Concise Natural History. Cambridge UP, 2009.
Howlett, E. A., et al. "New Light on the History of Megalosaurus, the Great Lizard of Stonesfield." Archives of Natural History, vol. 44, no. 1, 2017, pp. 82–102. Evironment Complete, search.ebscohost.com/login.aspx?direct=true&db=eih&AN=122205558&site=eds-live. Accessed 15 Apr. 2020.
Katz, Brigit. "Three Ferocious Dinosaurs Featured on New U.K. Coins." Smithsonian Magazine, 24 Feb. 2020, www.smithsonianmag.com/smart-news/original-triumvirate-dinosaurs-featured-new-uk-coins-180974253. Accessed 15 Apr. 2020.
Martin, Anthony J. Introduction to the Study of Dinosaurs. Blackwell, 2006.
"Megalosaurus." Natural History Museum, www.nhm.ac.uk/discover/dino-directory/megalosaurus.html. Accessed 15 Apr. 2020.
Norell, Mark, Lowell Dingus, and Eugene S Gaffney. Discovering Dinosaurs: Evolution, Extinction, and the Lessons of Prehistory. University of California Press, 2000.
Paul, Gregory S. Scientific American Book of Dinosaurs. St. Martin's, 2003.
"The Paleontology Portal." UC Museum of Paleontology, University of California, Berkeley, paleoportal.org/. Accessed 15 Apr. 2020.