Iguanodon

Iguanodon Lived between 140 and 90 million years ago. They were the precursors of the Hadrosaurids being among the most common herbivorous dinosaurs of the late Jurassic and early middle Cretaceous period. They were evolved from Hypsolophodontids and Camptosaurids which were common during the late Jurassic. Iguanodon would have been about as long as a school bus and weighed as much as the heaviest elephant. It probably stood on all fours most of the time eating low lying vegetation but could also stand up on two legs and eat leaves off of low hanging branches. Iguanodon are known to have been widespread in Europe, and North America with relitives in Africa, and Australia as well.

Iguanodon was most likely a gentle herbivore that moved in vast herds. It is believed that Iguanodon was primarily a quadruped but could also run on two legs for short intervals. They had a unique adaptation in their hands, four fingers and a large 6 inch spike in the place of a thumb. Many paleontologists believe this was a defensive weapon for use against predators. The thumb spike could have also been a display item among individuals to distinguish hierarchy within a herd. Iguanodon may have evens used the spike to skewer fruits.

On the Isle of Wight it was once thought there were two basic species of Iguanodon; a larger type known as Iguanodon bernissartensis, and the smaller Iguanodon atherfieldensis. I. bernissartensis was named for the Belgian town where complete skeletons were discovered (Bernissart). I. atherfieldensis was found in Atherfield on the south west coast of the Isle of Wight. Recently palaeontologist Gregory S. Paul has moved the smaller species to a new genera, leaving only the one Iguanodon but a new genera of Iguanodontid, Mantellisaurus atherfieldensis (named for Gideon Mantell). It was hard to classify these animals from limited fossil information available during the Victorian era. As a result many species names have been removed from the fossil record. Iguanodontid dinosaurs are amongst the most common fossils to be found on the Island to date. They might have been accumulated by local fishermen who worked along the coastline. William Smith had found Iguanodon fossils at a quarry in Sussex in 1809. It is believed that Dean William Buckland had discovered Iguanodon remains on the Island before 1822. In the early 1800's Dr. Gideon Mantell, a naturalist had also come across some Iguanodon teeth from Cuckfield when him and his wife were out riding. Mrs. Mantell found the teeth and showed them to her husband who was stunned. William Conybeare advised Dr. Mantell on using the name 'Iguanodon' due to a resemblance they appear to have with modern Iguana teeth. Mantell published his findings in 1825. This made Iguanodon the second dinosaur that was named after the theropod, Megolasaurus. Mantell's original concept was of a large tree-climbing lizard with huge claws and a spike on the tip of it's nose.Naturalist Sir Richard Owen also described his idea of Iguanodon as a heavy ground dwelling lizard-like creature and his interpretation was presented in the Great Exhibition at Crystal Palace during 1853-4. Sculptor Benjamin Waterhouse Hawkins built two large Iguanodon statues amongst other dinosaurs and prehistoric creatures based on Owen's vision. The Crystal Palace still has them there today, and the Iguanodons still have thumb spikes on their noses.