Isle of Wight Where Dinosaurs Roamed

With the release of a map showing dinosaur discoveries made in the United Kingdom, the Isle of Wight, an island off Britain’s south coast has been declared the “dinosaur capital of Great Britain”.  It is true that there have been some remarkable dinosaur fossil discoveries made on this island which is separated from the English mainland by a stretch of water called the Solent. The island has long since been known as “Dinosaur Isle” amongst palaeontologists and geologists who happen to frequent the southern part of the island exploring the Purbeck and Wealden strata of what is termed the Wessex Basin.

Dinosaur Capital

Iguanodontids, hypsilophodonts, sauropods, armoured dinosaurs and theropod meat-eating dinosaur fossils have all been found on the Isle of Wight.  There are also numerous dinosaur footprints and tracks that can be seen on the foreshore at Chilton Chine and other parts of the coastline.  Much has been made of the discovery of the fierce, meat-eating dinosaur known as Neovenator (Neovenator salerii).  This theropod dinosaur is known from a single specimen discovered nearly thirty-five years ago.  Neovenator means “New Hunter” and this dinosaur, tentatively assigned to the Carcharodontosauridae, may have measured more than 8 metres in length.  It would have been dwarfed by some of the sauropods that shared its Early Cretaceous environment.  Fossil discoveries made on the Isle of Wight indicate that there were brachiosaurids present and some of these long-necked herbivores could have weighed in excess of fifty tonnes.

A Model of the Fearsome Neovenator Dinosaur

“New Hunter” from the Isle of Wight.

Picture credit: Everything Dinosaur

Cretaceous Strata

The Cretaceous strata that makes up the southern part of the Isle of Wight is indeed important.  It is not just dinosaur fossils that make this a significant location, palaeontologists have been able to painstakingly build up a picture of an palaeo-environment.  In 2009 Doctor Steven Sweetman of the University of Portsmouth published a new, scientific paper outlining nearly fifty newly identified prehistoric vertebrates, whose fossils had been found eroding out of cliffs on the island.  Amongst the new genera erected there were six new mammals, eight dinosaurs, including large, predatory dromaeosaurs (raptors) and fifteen new members of the Order Squamata (lizards and snakes).

During the Early Cretaceous (135 million years to 130 million years ago), the land we now know as the Isle of Wight formed part of an extensive flood plain that linked the continents of the Americas, Africa and Europe.  More fossils are being found each year and palaeontologists are able to build up quite a detailed picture of the Cretaceous fauna and flora.

Not wishing to diminish the importance of the Isle of Wight, it is also worth remembering that a number of significant dinosaur finds have been made elsewhere in the British Isles.  A considerable amount of Jurassic-aged dinosaur fossils have been found in North Yorkshire, the Isle of Skye has some amazing dinosaur tracks and fragmentary dinosaur bones, then there is the county of Surrey with its Baryonyx fossil discovery and our own personal favourite, the city of Bristol, with its Thecodontosaurus.  The first fossils of Thecodontosaurus were found at a site just to the north of the city’s bustling centre, these fossils were found in 1834.

To read an article about Bristol honouring its very own dinosaur: Bristol Remembers its Very Own Triassic Dinosaur.

The Importance of the Isle of Wight

Then there are the megalosaurs and other dinosaurs from Oxfordshire, the Dorset Scelidosaurus, iguanodonts from the Wealden Formation outcrops of Kent and Sussex.   In fact, there are a number of important locations in the UK in terms of the dinosaur fossils found at these sites.  After all, the first dinosaurs to be ascribed to the newly erected Order Dinosauria were all species, whose fossils had been found in southern England.

For models and replicas of dinosaurs, including many dinosaurs associated with the Isle of Wight: Prehistoric Life Models (CollectA Age of Dinosaurs).

The Dinosaur Map of Britain

Dinosaur “Hot Spots” as we at Everything Dinosaur call them.

The research compiled by palaeontologists at the London Natural History Museum who tracked dinosaur fossil finds recorded over the last 336 years, was carried out as part of the publicity material for the television series “Primeval New World”, a spin-off from the earlier ITV programmes about a team of adventurers battling against worm holes that keep bringing prehistoric creatures back to the present day.

Lizard-Eating Sovereign of the Sea – Thalattoarchon saurophagis

Discovered back in the late 1990s and finally collected in 2010 but with a scientific description just published; the ichthyosaur family of marine reptiles has a new member.  It might have been appropriate to describe a number of ichthyosaur genera as dolphin-like but this newly erected genus has a closer affinity to the likes of the Orca (Killer Whale) in terms of where it would have been placed on the food chain.  The newly described Thalattoarchon saurophagis (the name means lizard eating sovereign of the sea), would have been an apex predator in the tropical MiddleTriassic sea that this prehistoric monster swam in.

Thalattoarchon saurophagis

The fossils were found in Triassic aged deposits (approximately 244 million years old) from the Favret Canyon region in the arid Augusta Mountains in the state of Nevada (western United States).  Much of Nevada today may be covered by dry scrub and desert but back in the Early Triassic this part of North America formed the eastern part of the vast Panthallassic ocean that covered most of the western hemisphere.  Within just eight million years or so of the Permian mass extinction event that may have wiped out as much as ninety-five percent of all life in the seas, it seems that marine environments and ecosystems had recovered sufficiently to permit the evolution of what is termed a “macro-predator”, a predator of other large creatures.  The discovery of these ichthyosaur fossils not only has important implications for the understanding of ichthyosaur evolution but perhaps more importantly, it suggests that marine ecosystems may have recovered more quickly from the Permian mass extinction than terrestrial ecosystems.

Fearsome Triassic Predator Thalattoarchon saurophagis

Sea monster of the Middle Triassic.

Picture credit: Raul Martin/National Geographic

One Individual Specimen

The fossils representing one individual specimen have been found to date, amongst strata that is rich in vertebrate fossil remains including several types of ichthyosaur.  The fossils of this predatory reptile include part of the back of the skull and the rear most portion of the jaws, much of the vertebrae, many of which were in articulation with each other, parts of the hips and some of the bones from the rear fins.  Using this material and comparisons with other better-known Triassic ichthyosaurs, the research team have estimated that this ichthyosaur may have reached over eight and a half metres in length.  Interestingly, living alongside Thalattoarchon was another, perhaps even bigger ichthyosaur – Cymbospondylus which may have reached lengths of ten metres or more.

Fossils of  T. saurophagis (Top predator)

The formidable skull and jaws of T. saurophagis.

Picture credit:  Fröbisch et al

The picture above shows the top of the skull (dorsal view) with a side view of the fossil material (lateral view).

The teeth of Cymbospondylus are typical of many other ichthyosaurs, the are conical and pointed, ideal for grabbing slippery prey such as cephalopds and fish.  In contrast, the teeth of T. saurophagis are very different.  The teeth are proportionately larger, some are up to 7 centimetres in length and they are  wider with anterior and posterior cutting edges.  The teeth are very blade like, and resemble the teeth of terrestrial theropod predators such as the allosaurids, although they do lack any serrations along the cutting edges (denticles).  These teeth are those of a macro-predator, an animal that specialised in catching, killing and eating other marine reptiles.

Along with Cymbospondylus, the shallow sea that would have covered much of the western United States was home to a genus of much smaller ichthyosaur known as Phalarodon.  It has been speculated that T. saurophagis hunted these smaller ichthyosaurs.

For models and figures of ichthyosaurs and other marine reptiles: Wild Safari Prehistoric World Figures.

Blade-like Teeth of this Frightening Ichthyosaur

The teeth of an apex predator.

Picture credit: Fröbisch et al

Similar to Cymbospondylus

Thalattoarchon may have resembled Cymbospondylus in having a long, streamlined body ending in a flexible tail with a rudimentary caudal fin but the head is much bigger when compared to the body proportions of the known fossil material of Cymbospondylus.  The head of Thalattoarchon is approximately twice the size of the head of Cymbospondylus in relation to the rest of the animal’s body.  The scientists responsible for the study including Dr Nadia Fröbisch of the Museum für Naturkunde (Berlin, Germany), have been able to create a model of the food chain that existed in this part of the Panthallassic ocean, placing Thalattoarchon in the apex position, at the top of the food chain.

A Model of the Mid Triassic Marine Ecosystem (Food Chain)

A Triassic marine food chain.

Picture credit: PNAS

The paper detailing the research carried out on these ichthyosaur fossils and the scientific description has been published in the academic journal “The Proceedings of the National Academy of Sciences”.

New Study into the Lark Quarry Dinosaur Footprints

The Lark Quarry located near the town of Winton in Queensland (Australia) is the site of one of the most important collection of dinosaur tracks discovered to date.  When these tracks were first studied by Dr Tony Thulborn and his colleague Mary Wade and their work published in 1984, the footprints caused a sensation as the various trackways were interpreted as herd of smaller ornithopod dinosaurs in the company of some coelurosaurs stampeding after they were cornered by a lumbering giant theropod dinosaur.

Lark Quarry Dinosaur Footprints

Ichnologists (scientists who study trace fossils, especially footprints), assigned the name Wintonopus to the small, ornithopods, Skartopus to the larger coelurosaurs and the eleven prints believed to describe the large, predatory theropod attempting the ambush were assigned to Tyrannosauropus.  However, a new paper published in the academic publication “The Journal of Vertebrate Palaeontology” interprets the tracks in a very different way.

Lead author, Queensland palaeontologist Anthony Romilio presents evidence to suggest that these footprints are not evidence of a dinosaur ambush with a resulting stampede but the tracks made by dinosaurs as they forded a river.  Instead of “Walking with Dinosaurs”, this new research suggests a scenario of “Swimming or even Wading with Dinosaurs”!

Tri-dactyl Prints at the Lark Quarry Site (Queensland)

Evidence for swimming dinosaurs?

Picture credit: Dr Steve Salisbury

Upper Cretaceous Fossil Tracks

The footprints are believed to date from around 95 million years ago approximately (Albian to Cenomanian faunal stages of the Cretaceous), the strata that the footprints were discovered in does represent fluvial deposits (river sediments), however, this new interpretation proposes that the tracks were made by dinosaurs whilst in the water and not on the river bank.   Walking along a river bed, especially one where the water may have been no more than forty centimetres deep would have made sense if the banks were heavily vegetated, progress through dense scrub and forests would have been much slower if the dinosaurs had chosen a land route.

The Queensland palaeontologist stated:

“Many of the tracks are nothing more than elongated grooves, and probably formed when the claws of swimming dinosaurs scratched the river bottom.  Some of the more unusual tracks include ‘tippy-toe’ traces – this is where fully buoyed dinosaurs made deep, near vertical scratch marks with their toes as they propelled themselves through the water.”

The smaller dinosaurs, those referred to as Wintonopus may have swum, whilst the larger dinosaurs were able to wade across the water.

Swimming Ornithopods at the Lark Quarry Site

Dinosaurs going for a dip!

Picture credit: Anthony Romilio

In the paper, the scientist argues that it is difficult to see how the tracks could have been made by an animal walking or running on land, even one panicked by a ambush from a predator.  If the tracks had been made on land the impressions made would have been much flatter.

Fossilised Footprints

Fossilised footprints of a swimming dinosaur have been found in the past.  There is a very important single dinosaur trackway discovered in Spain that seems to show a tri-dactyl, theropod dinosaur touching the bottom of a lake occasionally as it swam across it.  The sediments preserve the claw marks and impressions made by the dinosaur at it touched the lake bed and pushed itself off again to continue its journey.

To read an article on the Spanish discovery: Swimming Dinosaurs.

The Lark Quarry site represents one of the most important sets of dinosaur footprints known to science.  More than 3,000 individual prints have been identified so far.  A number of the tracks, including the “dinosaur stampede/river crossing site” are on public display.

Using three-dimensional footprint mapping techniques, the University of Queensland scientist has already provided a number of new insights into the dinosaur tracks of Lark Quarry.  In 2010, Anthony Romilio published a scientific paper that suggested that the footprints assigned to the meat-eater Tyrannosauropus were actually made by a large, herbivorous ornithopod, a dinosaur similar to Muttaburrasaurus for example.

To read about the research into the Tyrannosauropus tracks: Lark Quarry Dinosaur Tracks Re-assessed.

Commenting on the newly published research and reflecting on the earlier work suggesting that the large dinosaur tracks were not made by a predator, Anthony stated that taken all together, the research suggested that the Lark Quarry sediments did not portray a dinosaur stampede.

For models and replicas of Australian prehistoric animals: Australian Dinosaurs and Prehistoric Animal Figures (CollectA).