Named By: Gregory S. Paul - 2007.
Synonyms: Heterosaurus?, Iguanodon atherfieldensis, Proplanicoxa galtoni?, Sphenospondylus?,Vectisaurus?.
Classification: Chordata, Reptilia, Dinosauria, Ornithischia, Ornithopoda, Styracosterna, Hadrosauriformes.
Species: M. atherfieldensis (type).
Size: About 7 meters long.
Known locations: England, Isle of Wight - Wessex Formation.
Time period: Barremian-Aptian of the Cretaceous.
Fossil representation: Several individuals, some of which are almost complete.
Mantellisaurus was originally described as a species of Iguanodon, I. atherfieldensis, but in 2007 Gregory S. Paul renamed the species as new genus. Paul chose the name Mantellisaurus in honour of Gideon Mantell, the man who discovered and named Iguanodon. Mantellisaurus was capable of movement in either a quadrupedal or bipedal posture, and is noted for having a similarity with the dinosaur Ouranosaurus from North Africa. Trackways from the same location that the Mantellisaurus holotype fossils are known from indicate that Mantellisaurus travelled in family groups.
- Turning the old into the new: a separate genus for the gracile iguanodont from the Wealden of England. - Horns and Beaks: Ceratopsian and Ornithopod Dinosaurs 69-77. - Gregory S. Paul - 2007.
- A revised taxonomy of the iguanodont dinosaur genera and species. - Cretaceous Research 29 (2): 192–216. - Gregory S. Paul - 2008.