Megalosaurus will forever hold a special place in the hearts of palaeontologists as it was the first dinosaur to be officially named and described. It was the English clergyman and geologist William Buckland who was given the task of studying a piece of lower jaw (dentary) from a fossil discovered in Oxfordshire. The year was 1824 and in his paper the Reverend Buckland named this animal Megalosaurus "great lizard".
William Buckland did not actually come up with such an evocative name as Megalosaurus, he borrowed this term from a fellow scientist James Parkinson who had used the term two years earlier. However, no matter how Megalosaurus got its name, its name is here to stay. The holotype species is M. bucklandii, named after William Buckland, a lasting legacy to one of the early pioneers of this science.
The Reverend William Buckland - An English Eccentric
William Buckland was one of the founders of modern vertebrate palaeontology and although considered eccentric (keeping bears and jackals in his house), he continued to play an important role in the study of prehistoric animals. William Buckland is also credited as being the first person to collect dinosaur fossils from the Isle of Wight and to describe and record for scientific purposes the first dinosaur bones from the island. The Isle of Wight, off England's south coast is regarded as one of the world's most important dinosaur fossil sites. Exposed strata on the southern part of this island dates from the Early Cretaceous geological period and over the last two hundred years or so a number of important prehistoric animal discoveries have been made by excavating the Upper Cretaceous aged rocks. The sedimentary rocks in this area have provided scientists with fossils of many dinosaurs, animals such as Iguanodon, Hypsilophodon, Baryonyx and Neoventator. Fossils of one of the earliest members of the Tyrannosaur family, a dinosaur known as Eotyrannus have been found on the Isle of Wight.
The Order Dinosauria
Megalosaurus along with Iguanodon and the armoured dinosaur Hylaeosaurus was one of the three founding genera in the order Dinosauria. However, study of Megalosaurs has been blighted by a problem which has limited our knowledge on these meat-eaters.
Generally, fossils of carnivores are rarer than herbivores in the dinosaur fossil record. As a rule of thumb, the higher an animal is up the food chain the fewer of them there are, so there is less chance of one becoming a fossil. Limited remains of carnivores compared to herbivorous dinosaurs has been cited as evidence that these animals were warm-blooded.
Evidence for Warm-Blooded Dinosaurs
In Africa for example, the ratio of lions to prey animals in a healthy diverse population is approximately 1 predator to 20 prey, in areas where Nile crocodiles are the major predator the ratio of predator to prey is nearer 5 to 20 prey. Crocodiles, being cold-blooded do not need to eat as much as their mammalian, endothermic competitors - so larger numbers of them can be sustained by equivalent populations of prey animals. Scientists examine the ratios of meat-eating dinosaur fossils to plant-eating dinosaur fossils that have been found in the same locality. The analysis of this fossil material provides evidence as to whether or not dinosaurs were endothermic (warm-blooded) or ectothermic (cold-blooded). Although the results are open to extensive interpretation and debate, there is considerable evidence to suggest that like birds and mammals, dinosaurs were indeed endothermic (warm-blooded).
Only a few fragmentary remains of Megalosaurs have been found in Europe. As a result, many small fossils and pieces have been attributed to the genera Megalosaurus, when in fact they may well belong to entirely different types of carnivorous dinosaur.
The Meat-Eaters Known as the Megalosaurs
The genera Megalosaurus has been described as the "dumping ground for fossil rubbish" - rather sad considering it was the first dinosaur to be officially described.
The cladogram of dinosaur Theropoda (generally a group of dinosaurs that were the meat-eaters), is still poorly understood and hotly debated. Much of the attention is currently focused on the Oviraptorosauria and Eumaniraptora as scientists uncover more evidence over the origin of birds, but for many palaeontologists and scientists they feel that the likes of Megalosaurus deserve our attention too.
It may not have been the biggest meat-eater (perhaps nine metres long and three metres tall at the hips), but it was the first dinosaur described, it got the ball rolling as it were.
Mixing Up Fossil Remains
Many of the fossils previously cited to Megalosaurus may actually belong to other Tetanurae (stiff-tails) such as Eustreptospondylus (also found in Oxfordshire) or other genera as yet described. The relationship Megalosaurus has had with European science goes back further than 1822, one hundred and forty-six years earlier a partial femur (thigh bone) had been described and studied. Unfortunately, enormous, extinct, bipedal reptiles were beyond the educated men who examined it - instead they claimed it was from a giant man.
New Regions to Explore for Prehistoric Animal Fossils
Megalosaurus and its links with natural history have been noted by the Natural History museum who produce a 1:40 scale model of a Megalosaurus, complete with ferocious looking tiger stripes. As palaeontologists explore other areas of sedimentary rock, most notably in Spain in Portugal it is likely that more Megalosaur fossils will be discovered. These will help to fill in the gaps in terms of our understanding of how these meat-eating dinosaurs evolved. There are probably a number of Megalosaur fossils awaiting discovery in North Africa and with the recent changes brought about by what is termed the "Arab Spring", areas once inaccessible to western science may be opened up for exploration. These areas too, are likely to provide more fossils of Megalosaurs and their close relatives, helping scientists to piece together the taxonomic relationships between different types of dinosaur.
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