Iguanodon is the name of a small group of dinosaurs within the much larger group called Iguanodontids; they were large herbivores, with a long tail for balance, and hind legs that were longer than their fore limbs. There were three large hooved toes on each foot, and four fingers and a thumb spike on each hand. The mouth had a battery of chewing teeth, and a boney beak in place of front teeth. Since its initial discovery in the early nineteenth century, and more detailed reconstructions after complete skeletons were found in a Belgian mine in 1878, we have been forced to re-evaluate its posture, shape and movement; and to look again at how it fits in with other members of the Iguanodontids. Fossil remains from the group show they existed from the late Jurassic through to the late Cretaceous.
Here on the Isle of Wight it was once thought there were two basic species of Iguanodon; a larger form called Iguanodon bernissartensis, and a more graceful species called Iguanodon atherfieldensis. The first was named after the Belgian town where complete skeletons were found (Bernissart) and the latter from Atherfield on the south west coast of the Isle of Wight. However more recently palaeontologist Gregory Paul has moved our smaller variety to a new genera, leaving us with only one Iguanodon but a new genera of Iguanodontid called Mantellisaurus atherfieldensis (named after Gideon Mantell) in its place. It was initially very difficult to identify, name and group these animals from the fragmentary information that was first available in the Victorian era. As a result a number of species names have now been discarded.
No comments:
Post a Comment