Megalosaurus Footprints being Prepared for Display

Fossilised tracks made by a fierce Jurassic carnivore, Megalosaurus when Oxfordshire was part of a sub-tropical paradise have made a perilous journey to their new home, where they will go in display in the Autumn.

The fossil footprints, measuring 50 cm across have been transported from the temporary storage site to the Oxfordshire Museum, where they will feature in a permanent exhibit dedicated to the dinosaur that is believed to have made these prints – a Megalosaurus.

Fossilised Footprints

The short trip to the museum marks the end of 10 years of excavation and planning after the trackway was first uncovered at a landfill site in Ardley, close to Bicester.  The twenty-five mile trip from the storage site, where the fragile prints were prepared for their perilous journey, to the museum took five hours.  Project Manager, Tom Freshwater, who works at the Oxfordshire Museum, commented:

“The prints weigh three tons each so the main challenge has been getting them into the garden, where they will be displayed.  They had to be lifted very gently and smoothly because the rock is quite fragile and there are already cracks within the stone so we had to make sure that did not get worse.”

The fossil dinosaur footprints had been excavated in sections, of approximately 1 cubed metre, they were encased in plastic sheeting to protect them and set on steel plates to support the weight of the stone as the rocks made their journey.  Having arrived safely at the Museum, each block was carefully winched over the Museum boundary fence into a specially prepared garden area.  A great deal of care had to be taken as each block was lifted off the lorry, swung over the fence and placed in position.  Despite their weight, the blocks are delicate and every precaution was taken to prevent any damage to the fossils.

A Jurassic Environment

The Museum plans to create a replica of the Jurassic environment and display the prints alongside a life-size model of a Megalosaurus.  About 30 to 40 prints were originally discovered at Ardley Landfill and Recycling Centre, run by Viridor Waste Management, and those not been transferred have been preserved in situ.  The prints are very important as meat-eating dinosaur tracks are exceptionally rare and these particular prints, believed to have been made by a megalosaur provide evidence of a change of speed of the animal.  The spacing between the prints gets longer, indicating a bigger stride length and an increase in speed of the animal.

The exhibit is likely to be opened in October.

An Illustration of a Megalosaurus Footprint

Picture credit: Everything Dinosaur

Megalosaurus

Megalosaurus was the first dinosaur to be named and scientifically described, although the original specimen (known as the holotype), consists of a partial lower jaw, some teeth and a few scraps of fossil bone, it appears that this dinosaur was a fierce, general carnivore, perhaps the top predator around at the time.  Although, scientists have improved their knowledge of European carnivorous dinosaurs (thanks to a number of new finds that have come to light over the last twenty years or so), the Megalosaurus genus has gained a bit of a reputation as a dumping ground for theropod miscellany.  A number of carnivorous dinosaur fossils have been assigned to Megalosaurus, approximately 50 different genera have found themselves classified as Megalosaurus at one time or another.  The exact taxonomic relationship between these various carnivorous dinosaurs remains uncertain but at least attempts have been made to re-define the characteristics of Megalosaurus and establish other genera for meat-eating dinosaur fossils.

Megalosaurus has been referred to as a “waste basket genus”, to read an article on this: Megalosaurus – a Dinosaur Waste Basket.

Megalosaurus fossils are known from Europe and Africa, it is believed that they were capable of growing up to 9 metres in length, although the fossil trackway was made by a dinosaur estimated to be 7 metres long.  Although it is impossible to precisely identify the exact species of dinosaur that made the prints, the tracks may have been made by a sub-adult animal.  Estimates of the weight of megalosaurs vary, but the not fully grown animal that left its prints in the soft Jurassic mud all those millions of years ago, would have weighed more than 1,000 kilogrammes.

The Natural History museum created a scale model of Megalosaurus when they launched their dinosaur model collection a few years ago.  They coloured this model in orange and grey stripes, although purely speculation these markings would have helped break up this fierce hunter’s outline keeping it hidden and help it ambush prey.

Megalosaurus replica dinosaur model.

To view the Natural History Museum models: Natural History Museum Dinosaur Models.

Should Brachiosaurus be called Giraffatitan?

Brachiosaurus is one of the most popular dinosaurs with young dinosaur fans.  It normally rates quite highly in the annual Everything Dinosaur most popular prehistoric animals survey.  Brachiosaurus has not quite made the top ten yet, but it tends to be placed in the top twenty of children’s favourites.

To read more about our annual survey: Top Ten most popular Prehistoric Animals 2007/8

However, researchers studying an ancient dinosaur skull found nearly 100 years ago, could challenge much of what we know about Brachiosaurus and their work may even result in a name change for some fossils of this dinosaur.

Brachiosaurus

Brachiosaurs were sauropods (large, long-necked dinosaurs) that lived during the Late Jurassic and Early Cretaceous.  The name brachiosaur (pronounced brak-ee-oh-saw-us), means “arm lizard”, brachiosaurs had front legs that were longer than their back legs.  The back sloped downwards towards (by sauropod standards), a relatively short tail.  Brachiosaurs were the “giraffes” of the Mesozoic, their long stiff necks enabled them to reach high into the tops of trees to browse.  This gave them access to a food supply that was out of reach of most other dinosaurs.  Other sauropods could have fed on the tops of conifers and such like too, but they could only have reached the uppermost branches by rearing up or simply bulldozing the trees to the ground with their massive bulk.

A Typical Illustration of Brachiosaurus

Picture credit: Everything Dinosaur

Huge Animals

Estimates of the maximum size of these huge creatures vary; with weights of between 15 and 78 tonnes being put forward by scientific authors.  There is some consensus that the very largest specimens may have weighed between 50-70 tonnes, even at the lower end of the scale this is getting on for ten times the weight of an adult African elephant.

Despite this animal’s great size, its fossils are relatively rare.  Such big bones would have been difficult for scavengers to damage and remove from the rest of the carcase.  Large bones such as the limb bones and vertebrae could have withstood considerable abrasion before finally getting the chance to be fossilised.  A large Brachiosaurus, perhaps drowned in a flood event could float (large amount of gas in the digestive tract), and be transported many miles before finally coming to rest.  With luck the body could become covered with sediments and the slow process of fossilisation could start.  Of course this is just speculation, the fossil record for Brachiosaurus is particularly poor.  Even the extremely fossil rich Morrison Formation of the western USA has provided only one or two fossils of Brachiosaurus.  Perhaps these animals were less common than other sauropods such as the diplodocids, or perhaps they inhabited parts of the eco-system where the chance of fossilisation was much less.  The result is that scientists have very little fossil material of brachiosaurs to work on, despite these animals being one of the largest dinosaurs of all.

Brachiosaurus was named and described in 1903, by the palaeontologist Elmer Riggs, following study of two partial skeletons discovered in the Grand River Valley of Colorado, USA.  Although far from complete, these fossils indicated that this was a new type of dinosaur and so the Brachiosaurus genus came into being.

For a number of years, scientists claimed that such large and heavy creatures could not possibly have been able to move around on land.  This led to the sauropods being depicted as semi-aquatic animals, spending much of their time in lakes and swamps where the water could help support their huge weight.  This theory has now largely been dismissed and sauropods are depicted as entirely terrestrial animals.  The relatively high nostrils had convinced many scientists that these animals lived like giant hippopotami, peacefully feeding on soft, lush water plants away from predators.

To read more about the problems with sauropod nostrils: Where on Diplodocus was its nose?

Wild Safari Prehistoric World Brachiosaurus dinosaur model. Picture credit: Everything Dinosaur.

Picture credit: Everything Dinosaur

Animals at Home in Water

Dinosaur text books of the 1950s-1980s depicted these dinosaurs as semi-aquatic animals with brachiosaurs and other sauropods being depicted as water dwellers.  One of the reasons for this assumption can be traced back to studies of sauropod trackways.  Many of the fossil footprints had been made in soft mud, indicating that these animals were walking over wet ground, perhaps indicating that they were in a watery environment.  Soft mud is an ideal medium for preservation of prints, the fact that these animals walked over dry land as well could not be proved as there were no footprints fossilised to show this.  Bizarre logic, as prints are only preserved under exceptional conditions and are most unlikely to be preserved in dry conditions.  The absence of any tail marks in the mud where these animals walked was also noticed.  This added credence to the theory of the water living dinosaurs, as this was interpreted as the heavy tails being lifted clear of the ground and being buoyed up by the supporting water.  The prints were thus interpreted as showing these heavy animals walking along the bottom of lakes and rivers.

The best preserved and most complete fossils of brachiosaurids have been found in Africa.  Between 1909 and 1912 a German led expedition to the Tendaguru beds in what was to become Tanzania, uncovered a number of brachiosaurid fossils.  More than 30 individual brachiosaurs were found and excavated over this period.  Most of the fossils were shipped back to Germany and although some were destroyed in the Second World War, brachiosaur fossils from these expeditions are still on display today.

The huge, mounted skeleton of a brachiosaur in the Humboldt Museum in Berlin is a composite reconstruction using fossils found during the Tendagura expeditions.  This is one of the largest mounted dinosaur skeletons in the world.  It is in fact made up from the remains of a least five individuals and has recently undergone something of a makeover as our knowledge of brachiosaur anatomy has improved.

To read more about the work undertaken to reconstruct the mounted skeleton of a brachiosaur in the Humboldt museum: Humboldt Brachiosaur gets a Face Lift.

In 1988, palaeontologist and highly talented illustrator Gregory S. Paul, compared the anatomies of the African brachiosaurs (Tendaguru remains) with those found in the western USA.  He noted that there were a number of anatomical differences between the two fossil groups, although they supposedly represented the same species Brachiosaurus brancai.

Brachiosaurus and Giraffatitan

The African form seemed more gracile in appearance, it looked more lightly built than its American contemporaries.  Another difference was noted in the size and proportion of some of the vertebrae.  Paul reinterpreted the fossil evidence and suggested that the African Brachiosaur was sufficiently different from the American fossils to merit being put into its own subgenus.  During the Late Jurassic, Africa and the Americas were joined together into a super-continent, the Atlantic ocean that separates these areas of land today had only just begun to form.  It was possible to walk from what was to become Antarctica right up to the north of Canada.  It had been thought that the genus Brachiosaurus covered both the American and African forms, but Paul’s work was supported by another palaeontologist George Olshevsky and slowly the idea of a separate brachiosaurid genus for the African type began to take hold amongst some scientists.  The African brachiosaur was tentatively called Giraffatitan (the name is pronounced ji-raf-ah-ti-tan), it means “Titan Giraffe” very apt as the brachiosaur was regarded as filling a similar environmental niche as modern Giraffes.

The recent find of new American brachiosaur material may help scientists to determine whether or not Giraffatitan is a valid genus, at the moment the classification of brachiosaurid remains as Giraffatitan is still controversial, Giraffatitan is regarded as a synonym for Brachiosaurus by the majority of palaeontologists.  In classification terms a synonym is simply another name for the same organism.  There are senior and junior synonyms, in this case the name Brachiosaurus would be the senior synonym (first used in 1903) and Giraffatitan the junior synonym.

The recent discovery of a new dinosaur bone bed in the Morrison Formation may provide more data on the American brachiosaurs to aid comparison between the African and American animals.  This discovery, announced earlier this week is a fossil “log jam” a series of dinosaur fossils trapped together with a whole host of other fossil remains after a flood, or series of flood events.

To read more about this discovery: New Dinosaur “Log jam” discovered in the Morrison Formation.

It is believed that there are brachiosaur fossils amongst the new finds, this may help provide more information and help to resolve this issue amongst palaeontologists.  Ideally, more skull material would be found, this would enable further differences between the two species to be established and perhaps lead to many of the fossil specimens labelled Brachiosaurus in museum collections being relabelled as Giraffatitan.

Other skull material is currently being studied, a partial North American brachiosaurid skull found nearly 100 years ago has been studied by a number of researchers.  This skull is more box-like and lacks the distinctive high-crested appearance of the B. brancai holotype.  Skull material can prove to be very diagnostic and help determine differences between species.  If this skull is confirmed as being from a Brachiosaur such as the North American B. altithorax this would aid weight to the argument for permitting the establishment of Giraffatitan as a separate and distinct genus.

More brachiosaur remains will be found in the future, both in the USA and Africa, so hopefully the taxonomy of these huge reptiles will one day be a little clearer.

Everything Dinosaur stocks a wide range of sauropod figures, such as those in the Wild Safari Prehistoric World model range: Wild Safari Prehistoric World Models.

American National Park gets its very own Dinosaur

A dinosaur skull discovered in the American National Park called the Garden of the Gods in Colorado Springs, has been re-examined and declared a new species previously unknown to science.  A partial skull was discovered in the late 19th century within the park boundaries, it had originally been labelled as a Camptosaurus, but like a lot of camptosaur material it has been reclassified.   Much of what scientists thought of as camptosaur fossils have been reassessed and identified as iguanodontid.

Theiophytalia kerri

The Colorado Springs fossil has been named Theiophytalia kerri, the name loosely translated means “belonging to the Garden of the Gods”.  The species name has been taken in honour of James Hutchinson Kerr, a professor of geology who was credited with the fossil discovery.

The Garden of the Gods is a 1,300 acre national park, famous for its fantastic sandstone and limestone formations that between them cover something like 300 million years of Earth’s history.  This new dinosaur has been named by vertebrate palaeontologist Ken Carpenter, of the Denver Museum of Nature and Science.  From skull bones a lot of information can be obtained, skull bones are very diagnostic of dinosaur genera.  The Garden of the God’s skull indicates an ornithopod like Camptosaurus but it is sufficiently different to merit being classified as a different dinosaur genus.  It has been estimated that the animal was approximately 8-9 metres long and probably an adult (fused skull bones indicate a mature animal).

“I think it’s fun that Garden of the Gods has its very own dinosaur,” commented Bonnie Frum, the Director of the Garden of the Gods Visitor and Nature Centre, where a replica of the skull is on display.

It is not clear from which part of the park the skull was found, records of fossil excavations in the late 19th century, were at best sparse, some sites were not recorded at all.  James Hutchinson Kerr’s hand-written account is the only note of the fossil find and unfortunately the actual location was not recorded.

The notes, which can be viewed at the National Park’s Visitor Centre, provide only a limited amount of information:

“In 1878, I discovered in one of the ridges, east of the red rocks forming the east boundary of the Garden of the Gods, portions of 21 different sea monsters that had been caught as in a basin in one of Earth’s early paroxysms”.

The sediments to the east of the Park represent marine environments, fossil shells can still be found in the mesas in this area.  Perhaps, this dinosaur was washed out to sea and became preserved as a fossil in marine strata.  Other dinosaur fossils have been found in marine sediments, most famously Scelidosaurus, which is known from the early Jurassic strata of Lyme Regis.

To read more about Scelidosaurus: Britain’s most complete Dinosaur Fossil Discovered to Date ready for Display

An Early Cretaceous Herbivore

It is thought that Theiophytalia kerri lived during the Early Cretaceous, approximately 125 million years ago.  A herbivore, it would probably have lived in herds close to a large sea that covered much of the southern USA and the Gulf of Mexico.  This sea was part of the Tethys ocean soon to become part of the newly formed Atlantic.

The Garden of the Gods was named in 1859, surveyors from Denver looking to locate a new town in the state, came across the strange red sandstone rock formations and declared it being a place fit for Gods to assemble.  The name stuck and the area has been called the Garden of the Gods ever since.

The Garden of the Gods Park is a registered National Natural Landmark in Colorado Springs.  It  is open from 5 am to 11 pm in the summer and 5 am to 9 pm during the winter months.  It is famous for its beautiful and strange-looking geological formations made up of ancient sedimentary beds of red and white sandstones and limestone.  The layers of rock have been raised into vertical columns by faulting and are subject to substantial erosion, so more fossils may be found in the future.

Visit Everything Dinosaur’s website: Everything Dinosaur.