Open Paleo

Elrhazosaurus

Galton, 2009 el-RAH-zo-SOR-us

From Elrhaz (the Elrhaz Formation of Niger, where it was found) + Greek sauros (lizard): 'Elrhaz lizard'.

121.4–113.2 million years ago Aptian, Early Cretaceous
Early Cretaceous stages

Elrhazosaurus is a genus of basal iguanodontian dinosaur, known from isolated bones found in Early Cretaceous rocks of Niger. These bones were initially thought to belong to a species of the related dryosaurid Valdosaurus, but have since been reclassified.

Diagnosis

  1. Proximal end of lesser trochanter positioned below that of greater trochanter
  2. Transversely wide raised area separating the deep pit from the base of the fourth trochanter
  3. Extensor groove in distal view is deep and obliquely inclined postero-medially
  4. Extensor groove overlapped anteriorly by the acute-edged medial condyle

Species

Elrhazosaurus nigeriensis (Galton & Taquet, 1982)

Type species

First named as Valdosaurus nigeriensis

Named for Niger, the country where the holotype was collected from the Elrhaz Formation.

Holotype
MNHN GDF 332 , Muséum national d'Histoire naturelle
Material
Left femur.
Horizon
GAD 5 Bed, Elrhaz Formation, Aptian, Early Cretaceous , 121.4–113.2 million years ago
Locality
Gadoufaoua, niveau des Innocents, Agadez, Niger

References

  1. Galton, P. M.; Taquet, P. (1982). Valdosaurus, a hypsilophodontid dinosaur from the Lower Cretaceous of Europe and Africa. Geobios 15(2): 147-159.

    Names the species, as Valdosaurus nigeriensis, on GDF 332, from "GAD 5, upper part of El Rhaz formation".

    galton1982a
  2. Galton, P. M. (2009). Notes on Neocomian (Lower Cretaceous) ornithopod dinosaurs from England - Hypsilophodon, Valdosaurus, "Camptosaurus", "Iguanodon" - and referred specimens from Romania and elsewhere. Revue de Paléobiologie, Genève 28(1): 211-273. galton2009a
  3. Jones, B. (2026). The Princeton Encyclopedia of Dinosaurs: Ornithischians. Princeton University Press.

    Source of the body length estimate.

    jones2026a