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Dinosaurs of The Isle of Wight - Theropods

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Theropods are bipedal dinosaurs with stiff counterweight tails. Usually carnivorous, they ranged in size from Compsognathus, a 0.6m dinosaur found in Germany and Giganotosaurus, which was over 12 metres long.

Baryonyx

Baryonyx, or 'heavy claw', is a large theropod with an elongate skull, similar in appearance to that of a crocodile. First discovered in the Weald clay in Surrey in 1983 by Mr William Walker, Baryonyx walkeri and other baryonychids are believed to be related to Spinosaurids. Only one complete Spinosaurus aegyptiacus has so far been found. Sadly, after surviving fossilised for millions of years, it was destroyed during the desert phase of World War II. Its relationship to Baryonyx and Spinosaurids is consequently hard to tell. However, on a happier note, a new relative (Suchomimus) has been found in Africa which is bigger than either Baryonyx or Spinosaurus.

Baryonyx had a large number of teeth, 32 in each lower jaw and 7 in each premaxilla. The norm for theropods is 16 in each jaw and 4 in each premaxilla. The shape of the teeth and their number suggests that Baryonyx was a fish eater.

Baryonyx was probably the Isle of Wight's largest carnivore.

Aristosuchus pusillus

Meaning 'Small superior crocodile', Aristosuchus first found in 1876, it was believed to be intermediate between crocodiles and dinosaurs. It was also assumed by many to be the same species as Calamospondylus oweni, another small theropod discovered on the Isle of Wight. However, recent study has proved once and for all that Aristosuchus is a separate species.

The remains of Aristosuchus consists of the sacrum, pubis and aunguals, although other remains including a proximal right femur, a dorsal vertebra, a left tibia and two caudal vertebrae may also belong to Aristosuchus. These bones all resemble composagnathid remains. Aristosuchus would be approximately 2 metres long.

Calamosaurus foxii

'Fox's reed lizard' was described in 1889, based on two cervical vertebrae discovered by Reverend Fox and now stored in the Natural History Museum. The vertebrae are each 40mm long and show signs that the animal was fully grown, suggesting that Calamosaurus would have been around 3.5 metres long.

Calamospondylus oweni

'Owen's reed vertebra' is based on a specimen which, since its discovery in 1866, has gone missing. All that remain are the records that Reverend William Fox and Sir Richard Owen have of it, which gives us a detailed description, proving that it is not the same species as Aristosuchus pusillus, as has been thought. Fox precisely described a sacrum that consisted of "five cemented vertebrae..." and was 6 inches long, longer than the Aristosuchus sacrum by 32mm. A theropod with a sacral length of 6 inches, or 152mm, would be approximately 2.5 metres long.

Ornithodesmus cluniculus

Meaning 'bird-link small haunches'. When first described in 1887 the broken sacrum was believed to be a primitive bird, or pterosaur. However, it has recently been realised that it belonged to a theropod, approximately 1.5 metres long. This is guesswork, and more remains are needed to learn more about this animal.

Thecocoelurus daviesi

'Sheath hollow form' is based on the discovery of a vertebra found by Reverend Fox. It appears to belong to an Oviraptor. If so, it would be the first and only Oviraptor found in Europe. As this vertebra is around 0.09 metres long, it suggests an animal of between 7-9 metres long, quite large for an Oviraptor.

If it is an Oviraptor, then Thecocoelurus is likely to have been an omnivorous theropod that defended itself from larger predators with its large, curved claws. Little is known about Oviraptors. For a long time they were believed to be specialised egg-eaters. This was based on a single find in the Ghobi desert. An Oviraptor was fossilised curled up on a nest full of eggs. Science has come on a little way since then, and the eggs have been 'opened', revealing fetal 'Oviraptors' (egg seizers).

Neovenator salerii

Neovenator is an allosaurid, and the first confirmed allosaurid to have been found in Europe. Allosaurids were large predatory dinosaurs. Neovenator, or 'new hunter' is exceptional as over 70% of the skeleton was recovered. It was named after Mr Salero, on whose land the first Neovenator was found in 1978. In Europe, the only other large theropods to have been found as well preserved were Baryonyx and Eustreptospondylus.

Neovenator was a predator between 7 - 10 metres long and over 2 metres high. As a powerful carnivore, it would probably have ambushed, killed and eaten Iguanodons and sauropods. Several Neovenator remains were discovered during the Live From Dinosaur Island dinosaur hunt.

Megalosaurus

As Megalosaurus, or 'Giant lizard' was the first dinosaur to be named. Initially, most theropod dinosaur remains were considered to be Megalosaurus.

Any bones or teeth of roughly the right size or shape as Megaloaurus were considered to belong to Megalosaurus. It is now believed that most, if not all, of the teeth etc. found on the Island that were previously believed to belong to Megalosaurus may in fact belong to Neovenator, as no Megalosaurus remains have been positively identified on the Island. Megalosaurus, after all, lived in the mid Jurassic, while the Island's Wealden rock is from the early Cretaceous, a difference of around 50 million years, give or take a fortnight.

Megalosaurus was approximately 7 metres long.

Eotyrannus lengi

Named 'Early Tyrant', as a reference to the infamous Tyrannosaurus rex and 'lengi' after Mr Gavin Leng who discovered it, Eotyrannus lengi is the newest dinosaur to have been found on the Isle of Wight - it was only named in May 2001.

Eotyrannus appears to have been around 5 metres long, with long thin arms and legs. This suggests that it was a fast predator, able to use its teeth and claws in order to kill its prey. It is believed to have been an indirect ancestor of Tyrannosaurus rex, which lived 60 million years after Eotyrannus. It also was hunted for in the Live From Dinosaur Island Television series.

Dinosaurs Of The Isle Of Wight


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