Dinosaurs in the Museum
The Museum has an impressive collection of dinosaurs, and the footprints that span the front lawn give the first time visitor an idea of what to expect on entry. Inside the building a spectacular display of dinosaurs includes four species from Oxfordshire, and dinosaurs from around the world.
What is a dinosaur?
On first entering the Museum you are struck by the sight of the Iguanodon and Tyrannosaurus towering over you; most people recognise these as dinosaurs, but can get confused identifying other specimens.
Two simple facts will help you. Dinosaurs were reptiles that lived on land; they did not fly like the pterosaurs, or swim like the plesiosaurs and ichthyosaurs. Their legs were held directly underneath them; other reptiles, like crocodiles and lizards, walk with their legs held to the side of their body. Remember these facts when you visit the Museum and you shouldn't have any problems identifying a specimen again!
Prior to the 1800s scientists struggled to interpret early findings of large bones that were occasionally dug from quarries. In 1677 Robert Plot wondered if a bone, now recognised to be from a dinosaur, could have been evidence of an elephant brought to Britain by the Romans, but finally concluded it was the petrified bone of a giant!
The first dinosaur to be described and named was presented in 1824 as the 'Megalosaurus or great Fossil Lizard of Stonesfield'. The author of the scientific paper was William Buckland, professor of Geology at Oxford. The bones he described came from the nearby village of Stonesfield, and most of these are on display in the Museum today.
Richard Owen invented the word 'dinosaur' in 1842. Owen was a distinguished professor of anatomy and based his new grouping on the shared features of the large land-living reptiles Megalosaurus, Iguanodon and Hylaeosaurus. He saw that they shared certain features (including hollow limb bones, and five fused vertebrae where the spine fastens to the pelvis) and recognised that they were more than just the overgrown lizards others had seen them to be.
The dinosaur footprints
In the spring of 1997, Christopher Jackson, a Birmingham school teacher, learnt of the presence of dinosaur footprints on the floor of an old limestone quarry at Ardley, 20 kilometres northeast of the Museum. He contacted the Department of Earth Sciences in Oxford, and as a result, staff of the Department and the Museum described the site, casting parts of the better-preserved trackways. Between thirty and forty trackways are present and some are up to 200 metres long.
The footprint bed records a brief episode when this part of Oxfordshire was an area of mudflats, fringing a shallow-water area of sea and lagoons that extended north and west into what are now the Cotswolds. Two sorts of trackway are present, and these can be tentatively linked to the skeletal remains of dinosaurs known from the Jurassic rocks of Oxfordshire since the seventeenth century.
What made the footprints?
The bipedal carnivorous dinosaur Megalosaurus probably produced the three-toed footprints. The prints are up to 80 cm long, 65 cm wide, and 2 metres apart, and in some, impressions of claws are preserved. Calculations based on stride length show that the Megalosaurus was moving at about 2 miles per hour, though one section shows a speedy 20 mph. A 60 metre long trackway, made up of casts of the Megalosaurus footprints is displayed on the lawn in front of the Museum.
The 15 m long herbivorous dinosaur Cetiosaurus, probably made the second sort of trackway. It walked on all fours like the more familiar 'brontosaurus'. Where distinct, the front footprints are up to 40 cm long and kidney-shaped; those of the rear feet are larger, semicircular and up to 60 cm across. The great weight of the animals is indicated by the ridges of mud (now transformed into limestone), which form a rim at the front of the footprints. Again, calculations show that the animals were moving at less than 2 mph.
The Oxfordshire dinosaurs
The dinosaur displays in the Museum include four species from Oxfordshire, and two of these, Eustreptospondylus and Camptosaurus, are that great rarity in geology - complete skeletons. The bones of Megalosaurus, the first dinosaur ever described, and the giant herbivore, Cetiosaurus, are also on show.
In 1871, workmen in a brickpit in North Oxford discovered the skeleton of a dinosaur. It was acquired by an amateur geologist, given to the University, and described by John Phillips, the first curator of the Museum; it is now named Eustreptospondylus oxoniensis.
The skeleton of Eustreptospondylus was found in the 155 million year old Oxford Clay. Like Megalosaurus and Tyrannosaurus rex, it is a typical theropod dinosaur; a carnivore, it walked on its hind legs, with a large head armed with sharp blade-like teeth, a short neck, reduced forelimbs, and a long tail to balance its body. The skeleton on display is that of an immature animal, about four and a half metres long. It is the most complete example of a 'carnosaur' in Western Europe, and the only specimen of the species.
The skeleton of Camptosaurus was discovered in 1879 by workmen in a brickpit on Cumnor Hurst. The bones were dug out and cast aside, until a workman took a bag of them to George Rolleston, the Professor of Anatomy and Physiology at Oxford. Recognising their importance, he secured them for the University.
The skeleton of Camptosaurus was found in the 143 million year old Upper Jurassic Kimmeridge Clay and is the most complete skeleton of a camptosaur from Europe. Camptosaurs have a strong bony wrist and would probably have walked on all fours, but could also have raised themselves on their hind legs to browse on leaves and twigs. Their serrated teeth were well adapted for processing plant material, and were continually shed and replaced by newly erupted teeth throughout the animal's life. The Oxford specimen is the most complete member of the genus known from Europe, and is the earliest known representative of the large-bodied, quadrupedal, sometimes bipedal, herbivorous dinosaurs later represented by the iguanodontids.
Camptosaurus prestwichii gets its name from the Greek kamptos meaning 'flexible', and sauros, 'lizard'; the 'flexibility' came from the incomplete fusion of its vertebrae and skull, and suggest it could have been a juvenile. Its species name, prestwichii, was given for Joseph Prestwich, a professor of geology at Oxford.
The first published record of a dinosaur bone was in Dr Robert Plot's 1677 book The Natural History of Oxfordshire. Recognisable today as part of a single thigh bone of Megalosaurus, Plot wondered if it could have come from an elephant brought to Britain by the Romans, but concluded it was the petrified bone of a giant.
One hundred and fifty years later the geologist William Buckland acquired some bones from Stonesfield, north west of Oxford, but was unsure of their significance. With the end of the Napoleonic Wars, contact between English and French scientists was renewed, and in 1818 the great French comparative anatomist Georges Cuvier visited Oxford. Cuvier examined the Stonesfield bones and realised that they belonged to a giant animal resembling a lizard. Following Cuvier's visit, Buckland started describing the fossils in earnest, and he published an account of them in 1824. This account was the first scientific description of a dinosaur.
The Megalosaurus display includes most of the specimens from Buckland's description. A complete skeleton has never been found, but comparison of the bones with those of better known dinosaurs such as Allosaurus from North America suggests that Megalosaurus was a typical bipedal carnivore, seven or eight metres long and probably weighing around a tonne.
In the 1860s a series of bones were discovered in 163 million year old limestone in quarries near Bletchingdon Station, just north of Oxford. The huge bones in this collection probably belonged to several individuals, some of them juveniles. To date no skull has been found, but a few teeth that are thought to belong to this species have been discovered.
Most of the specimens on display were found in the 1860s by Mr Chapman, a watchmaker who 'discovered and rescued the monster Cetiosaurus at [Enslow Bridge]. He was on a botanising expedition with his son, and had just got off the train as the first fragment was disclosed by the pickaxe. He found the foreman, stopped the digging, and telegraphed to John Phillips, Professor of Geology and the first Curator of the University Museum, who super-intended the removal of the enormous bones to the Museum. The credit went to Phillips, no one remembered Chapman'. Bones of Cetiosaurus have also been found at Woodeaton a few miles north east of Oxford as recently as the 1980s.
Cetiosaurus was a typical sauropod dinosaur, with a small head on a long neck, a long tail, and elephant-like limbs. Footprints and tracks show that sauropods lived in herds. Although they usually walked very slowly, they could probably reach a speed of around 15 km per hour.
Other dinosaurs in the Museum
The dinosaur displays include species other than those found in Oxfordshire. They include Iguanodon bernissartensis, and the Tyrannosaurus rex of the central aisle of the Museum, and many other species in the geology section of the court.
The name Triceratops means three-horned face, referring to the one small and two large horns on the skull, which can be seen on the cast on display in the Museum.
Triceratops was 7.3 metres long, and weighed more than 6 tonnes. It was a herbivore, and its jaws were equipped with a constantly replaced battery of teeth specially adapted for cutting up tough plant material.
The horn and frill of Triceratops have attracted much speculation, but it is likely that they were used for display and fighting to maintain social dominance, and to defend territory and mates. Functional analysis suggests that Triceratops locked horns in pushing and twisting fights between individuals, the massive frill at the back of the skull acting as a shield to deflect the horns of opponents and protect the vulnerable neck and shoulder muscles.
The Museum has a cast of a skeleton of Edmontosaurus annectens. Edmontosaurus belongs to the group of herbivorous dinosaurs known as the duck-bills, because of their distinctive toothless, beak-like snout. The teeth and jointed skull of the animal show that it had evolved a complex grinding mechanism that allowed it to chew plant material efficiently prior to swallowing.
The original skeleton came from a bone bed containing thousands of skeletons and remains of the same species. The duck-bills were social animals, migrating in vast herds along the western shore of the great seaway that extended from the North Slope of Alaska to Mexico during the late Cretaceous. Bones of Edmontosaurus have been found in droppings of Tyrannosaurus rex, which probably followed the migrating herds, feeding on the young, weak, dying and dead.
The Museum has a cast of a skeleton of Struthiomimus sedens from the 65 million year old Lance Formation of Wyoming, USA. Its name means 'ostrich-mimic', and it shares some adaptive features in common with the ostrich and other large flightless birds.
Struthiomimus was a lightly built, agile dinosaur. Like the ostrich, it could run very fast, and some calculations suggest it would have reached speeds of up to 50 kilometres an hour - even faster than Usain Bolt running the Olympic 100 metres!
There is confusing evidence concerning Struthiomimus' diet. It lacked teeth, and one specimen was found with gizzard stones, which were used to grind food, and suggest a plant diet; however, the sharp claws on its hands may have been used to catch and hold prey, or were perhaps used to strip tender shoots and fruit from bushes and low trees.
Bambiraptor is a theropod, and a member of the same dinosaur group as Tyrannosaurus rex. The adult animal would have been about the size of a turkey and is similar to the more familiar Velociraptor. A comparison with the head of T. rex that is also on display, illustrates the huge size range of the theropods.
The Museum has a cast of a specimen of Pachycephalosaurus wyomingensis from the 65 million year old Upper Cretaceous Lance Formation of Wyoming, USA.
These animals were bipedal. They grew up to 4.6 metres long, and probably fed on a mixed diet of leaves, seeds, fruits, and insects. Their most distinctive feature is the massive domed braincase with a row of bony knobs at the rear, and a short, spiky snout, giving them their name 'thick-headed lizard'.
The massively reinforced skull suggests that Pachycephalosaurus was goat-like, and fought with 'battering-ram' collisions to establish mating rights and social dominance. This interpretation is supported by the structure of the vertebrae, which are designed to interlock and dissipate the shock of head-to-head impacts.
The Museum has a reconstruction of Utahraptor ostrommaysorum based on partial skeletal remains found in Utah, USA. Utahraptor was a close relative of the famous 'raptors' (properly called dromaeosaurs) such as Deinonychus and Velociraptor. Its hind foot was equipped with a large, retractable slashing claw. This was the main weapon of attack and would have been employed to deliver powerful kicks to the belly of unfortunate prey animals, quickly disembowelling them.
The discovery of Utahraptor coincided with the period during which the movie 'Jurassic Park' was filmed. Scientists were concerned that the Velociraptor models used in the film had been made too large, but Utahraptor provided evidence of raptors reaching the required 'cinematic' size.
In 1878 a group of thirty or so fully articulated dinosaur skeletons were found in a coal mine at Bernissart, Belgium. They were the most complete finds of their kind, and confirmed the new ideas emerging about dinosaurs, which were beginning to replace the prevailing view that dinosaurs were rhinoceros-like creatures. The Museum's Iguanodon is a cast of one of these specimens.
Iguanodons appeared in late Jurassic times and persisted until the end of the Cretaceous. Iguanodon bernissartensis lived about 115 million years ago, when the group was flourishing. It fed on plant material which it cropped with its horny beak and minced with a long battery of cheek teeth.
Although the Iguanodon skeleton in the main court is exhibited in a kangaroo-like posture, this stance is incorrect, and based on early ideas of how Iguanodon lived; looking closely you can see that its tail has actually been broken to pose it in this way. In fact, its strong hind limbs suggest it normally walked on two legs with its tail held aloft. The Museum also has a cast of the skull, and a reconstruction of the head of an original specimen from Belgium. The skull is exhibited in its true colour, black, and not the sandy colour of the skeleton in the central aisle of the Museum.
A cast of the skeleton of 'Stan', an adult T. rex stands in the central aisle of the main court. The skeleton was found in the 65 million year old Hell Creek Formation, South Dakota, USA. The skeleton shows signs of repaired wounds to both the limbs and head, the result of fights with other dinosaurs, in all probability, other T. rex.
T. rex is probably the most famous of all the dinosaurs. It was a theropod, and is known from about 20 specimens from the Upper Cretaceous of the North Western Interior of the USA. Its name comes from the Greek tyrannos, meaning 'tyrant', sauros, or 'lizard', and the Latin rex, 'king'; so, tyrant lizard king. The animal was up to 12 metres long, 4 metres high at the hip and weighed more than 6 tonnes. It had a skull up to 1.5 metres long, containing teeth, some up to 30 cm long. It walked on its large back legs and its small forearms were probably used to grasp prey. Its large, forward-directed eyes indicate that T. rex probably had three-dimensional vision.
Other prehistoric reptiles in the Museum
Dinosaurs may be the most famous animals from the 'age of reptiles', but the Museum also has displays of the other reptiles that lived during the Mesozoic. The southern area of the main court is devoted to the geological collections of the Museum; exhibits include casts and models of the dinosaurs described here, and four cases devoted to ichthyosaurs, plesiosaurs, pterosaurs and crocodiles. Although perhaps less famous, these animals dominated the seas and skies of the prehistoric world.
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