Saurischian dinosaurs are dinosaurs with 'lizard-like' hips. There are two main divisions of saurischian dinosaurs found on the Isle of Wight - Sauropods and Theropods. Sauropods are the often giant quadruped herbivorous dinosaurs that include some of the most famous dinosaurs known: Diplodocus, Apatosaurus and Brachiosaurus.

The Isle of Wight sauropods pose something of a problem for modern palaeontologists. Most of the fossil evidence on the Isle of Wight is fragmentary, and Victorian scientists often created a new genus and species name for every sauropod bone they discovered. So there may be a great many species of sauropod on the Island, or, alternatively, it may be that there are only a few species, with far too many names.

Modern-day palaeontologists have inherited a plethora of names for sauropod specimens, and are unwilling to add to the confusion by naming or in many cases even categorising new finds until they discover enough remains to make sense out of the confusion.

Chondrosteosaurus gigas

Chondrosteosaurus gigas, or 'Giant cartilage and bone lizard' - a reference to Owen's theory that the bone was filled with cartilage and not air sacs. Found on the Island in 1876, only two vertebrae have so far been recovered. These were vertebrae similar to Camarasaurus, suggesting that Chronrosteosaurus was a similar size, 15 - 18 metres long.

Pleurocoelus valdensis

Pleurocoelus valdensis, or 'hollow sided, from the Weald', was the name given by Lydekker to teeth discovered in Cuckfield, Hastings and Battle in Sussex in 1889. Similar teeth have been found on the Isle of Wight. These teeth were named after Pleurocoelus nanus, found in Maryland, USA, as Lydekker felt they were similar.

What is known is that the teeth of Pleurocoelus valdensis are different to the teeth of Oplosaurus armatus. No other Isle of Wight sauropod has been found with its teeth intact, so whether the teeth belong to another species, such as Chrondrosteosaurus, is impossible to tell.

Brachiosaur

In 1991, remains of a Brachiosaur were discovered near Atherfield and Brighstone on the Isle of Wight by Steve Hutt. After gaining permission from the farmers who owned the land, an excavation began, with the bones being temporarily stored in a barn. Approximately 40% of the skeleton was recovered, including an articulated shoulder and forelimb, as well as the hindlimbs and several ribs. The neck and much of the tail was not, however, recovered. Brachiosaurs can grow up to 25 metres long, and though this one appears to have been slightly over 15 metres, there are strong indications that it is a juvenile, due to unfused bones, and so may have reached a length of 23 metres when fully grown.

When news of the discovery was released, the Phillips (farmer's) family were besieged by visitors wanting to see the new dinosaur remains in their barn. Eventually it seemed that it was inevitable that their barn would become a museum, and is now the Island's Dinosaur Farm Museum.

The exact species of Brachiosaur is unknown. Four other species of Brachiosaurids have been discovered on the Island; Eucamerotus, Ornithopsis, Oplosaurus and Pelorosaurus.

Pelorosaurus conybeari

Pelorosaurus conybeari, meaning 'William Conybeare's monstrous lizard', was discovered through a humerus found in Cuckfield, Sussex, in 1849. A similar humerus was found in Sandown on the Isle of Wight in 1888. The humerus of a Brachiosaurus is similar, but less robust. The humerus of the so-far unnamed Brachiosaur from Brighstone is also different to that of Pelorosaurus, lacking the prominent posterior fossa. The humerus is 1.4 metres long. The humerus of Brachiosaurus altithorax is normally over 2 metres long. This suggests that Pelorosaurus would be approximately 16 metres long, and able to eat foliage in the treetops.

Oplosaurus armatus

Oplosaurus armatus (or 'armed armoured lizard') is a species of Brachiosaur that is known from very little fossil evidence; so far only one tooth has been found. When found in 1852, it appears that Gervais believed that it may have been the spike of a Hylaeosaurus-like animal. A large, and indeed beautiful, tooth, it is very similar to the tooth of Brachiosaurus, and so Oplosaurus is likely to be a brachiosaurid. At the moment it is unknown whether Oplosaurus is a new species in its own right, or whether it is analogous with Cetiosaurus, Pelorosaurus, Ornithopsis, Eucamerotus or the recently-discovered unnamed Brachiosaur. What is certain is that the tooth is unlike the teeth of Pleurocoelus valdensis.

The tooth is 85mm long. This suggests that it was from a large brachiosaurid of a Brachiosaurus size, between 22 and 25 metres long. A cervical vertebra discovered on the Island by Gavin Leng is the same size as the cervicals of Brachiosaurus, and so supports the belief that there was a Brachiosaur species of that size on the Island.

Ornithopsis hulkei

Meaning 'bird-like', and named after John Hulke, the first Ornithopsis remains found in 1870 were originally believed to have belonged to a pterosaur. Since then, several Isle of Wight brachiosaurid and sauropod bones have been labelled as Ornithopsis hulkei, without regard to whether they belong to same species or not, which at this time is unknown. However, the original bone discovered was a dorsal vertebra 22cm long. Cedarsoaurus has dorsal vertebrae 100mm long and was 10 metres long, Brachiosaurus has posterior dorsals around 40cm long, and was 25 metres long. It is not unlikely that Ornithopsis was around 15 metres long.

Ornithopsis eucamerotus

Meaning 'bird like, well chambered', Ornithopsis eucamerotus consists of a right pubis and ischium discovered by Reverend Fox. Hulke named it in 1882 in order to show that he felt that Ornithopsis hulkei and Eucamerotus foxii were the same species, and so combined their names in an attempt to combine the two specimens into one species. Whether this is true or not is impossible to know for certain until clearer remains are found.

Eucamerotus foxii

Meaning 'well chambered' and named after the Reverend Fox. The remains of Eucamerotus foxii consist of a number of dorsal verterbrae. Exactly which brachiosaurid Eucamerotus foxii may be is hard to tell, based purely on the vertebrae. They however appear to be different from the vertebrae labelled as Ornithopsis foxii. As the dorsal vertebrae of Eucamerotus are approximately 200mm long, compared with other brachiosaurids, a length of around 15 metres wouldn't be a bad guess.

Brachiosaurs - Conclusion

It is likely that many of the different remains discovered belong to the same species. Yet, as Polacanthus was long considered to be identical to Hyleaosaurus because no overlapping material had yet been found, nothing is conclusive.

Iuticosaurus valdensis

Meaning 'Jutish lizard, from the Weald', Iuticosaurus was a titanosaur discovered by Reverend Fox, yet not described until 1929 as Lydekker believed the bones to belong to Ornithopsis. Titanosaurs were the most widespread and diverse of the sauropods, with different species being between 5 and 30 metres long. Many Titanosaurs were armoured, with longer tails than necks, and wide hips. Although only vertebrae have so far been found, it is believed that Iuticosaurus would have been 15 - 20 metres long.

Titanosaurus lydekkeri

Lydekker's gigantic lizard is known only from a caudal vertebra bought by the Natural History Museum in 1857, and is believed to be from a titanosaur. Whether it is the same species of Titanosaur as Iutiocosaurus is impossible to tell. However, it appears likely that it too was a Titanosaur over 15 metres long.

Diplodocoids

Bones belonging to diplodocoids have also been found on the Island, although as with the Titanosaurs and Brachiosaurs, no complete remains have been discovered. In 1975, a diplodocoid chevron was found near Grange Chine, as well as caudal vertebra, a metatarsal and teeth have been found that all appear to belong to a diplodocoid, but a smaller one than Diplodocus carnegii, which grew to 24 metres long. The chevron suggests an animal around 16.6 metres long, providing that it was similar in proportion to Diplodocus carnegii.

Cetiosaurus brevis

Meaning 'Short whale-like lizard', Cetiosaurus brevis was a name created by Owen to describe remains discovered in Sandown Bay on the Isle of Wight, and Sussex. The bones from Sussex have since been found to belong to Iguanodon, and so after 1849, the name Cetiosaurus brevis has been used to describe the Isle of Wight material only.

As several bones have been found, Cetiosaurus brevis is the second most complete sauropod to have been discovered on the Isle of Wight. It is currently under further study.

Chondrosteosaurus magnus

'Mighty cartilage and bone lizard' is known from a partial dorsal vertebra found at the same location as Chondrosteosaurus gigas. However, recent study has shown that the two species do not belong to the same genus, for gigas appears to be a camarasaurid, and not a diplodocoid, although many feel that the vertebra is not complete enough to be certain. What is known is that the vertebra is large, and that therefore implies that the animal was large. Estimates suggest a length of at least 15 metres.

Dinosaurs Of The Isle Of Wight

• Dinosaurs of the Isle of Wight
• Why The Island Is Special
• Dinosaur Hunters
• Ornithischians
• Theropods
• Pterosaurs
• Live From Dinosaur Island