Ouranosaurus
| Key | Value |
|---|---|
| Name Meaning | “brave lizard” |
| Location | Niger, Cameroon |
| Time Period | c. 112 million years ago (Early Cretaceous) |
| Length | 25 ft (7.5 m) |
| Weight | 2.5 tons (2,250 kg) |
| Locomotion | Quadruped & Biped |
| Diet | Herbivore |
| Described | 1976 (Taquet) |
| Geological Formation(s) | Elrhaz, Koum |
| Valid Species | Ouranosaurus nigeriensis (type) |
Phylogeny: Dinosauria > Ornithischia > Genasauria > Neornithischia > Cerapoda > Ornithopoda > Iguanodontia > Ankylopollexia > Styracosterna > Hadrosauriformes (?)
Overview: During the 1960’s and 1970’s, teams of French paleontologists went into the deserts of Niger in search of fossils. Among those recovered was a set of remains belonging to a fairly large ornithopod dinosaur, bearing some rather distinctive features. In 1976, these fossils were used as the basis for the genus Ouranosaurus, the name of which is derived from both Arabic and Greek, meaning “brave lizard”. The name is also based on a similar word used by the local Tuareg people to refer to monitor lizards in the region. Ouranosaurus may’ve been named as such due to it having lived among some fairly fearsome theropods. Its fossils date back to over one hundred and ten million years ago, in the Early Cretaceous. Most of them were found within the rocks of Niger’s Elrhaz Formation, meaning it coexisted with dinosaurs like Lurdusaurus, Nigersaurus and Suchomimus. In that time, the region was fairly lush and wet, with marshes and numerous rivers.
The basic body plan of Ouranosaurus was mostly like that of other iguanodonts. It could walk up on its hind legs or down on all fours and grew to maybe seven or eight meters in length. What the genus is primarily known for, however, was its unusual neural spines. These spines, especially over its shoulder and upper back, were extremely tall. Some restorations, particularly older ones, depict these spines supporting a kind of skin sail. Such a sail may’ve been used for visual display or to help regulate its temperature by taking in or shedding heat. Alternatively, the spines may’ve supported a camel-like hump or ridge of fat and other such tissues, to store energy when food was scarce. The head was notable too, being quite flat in profile with a small crest above the eyes. Ouranosaurus was originally classified close to Iguanodon, in the Iguanodontidae. Later studies, however, find it to have been more derived than Iguanodon, or even in the hadrosauroid superfamily.