Open Paleo

Ajnabia

Longrich et al., 2021 aj-NAH-bee-uh

From Arabic 'ajnabia' meaning 'stranger' or 'foreigner', reflecting the unexpected presence of hadrosaurs in Africa

72.2–66.0 million years ago Maastrichtian, Late Cretaceous
Late Cretaceous stages

Ajnabia is a genus of lambeosaurine hadrosaur from the Late Cretaceous (Maastrichtian) of Morocco. It is the first definitive hadrosaur from Africa and is thought to be related to European hadrosaurs like Adynomosaurus and Pararhabdodon. The discovery of Ajnabia came as a surprise to the paleontologists who found it because Africa was isolated by water from the rest of the world during the Cretaceous, such that hadrosaurs were assumed to have been unable to reach the continent.

Diagnosis

  1. Maxillary neurovascular foramina with a hypertrophied foramen below the jugal articulation and a smaller accessory foramen below that
  2. Ectopterygoid ridge ventrally positioned on maxilla, weakly inclined relative to the dentigerous process, developed as a massive, dorsoventrally thick, rounded, lip-like structure
  3. Ectopterygoid ridge reduced anteriorly, failing to contact the jugal articulation
  4. Maxillary tooth crowns with tips curled medially, median ridge offset posteriorly, accessory ridges absent, denticles highly reduced
  5. Strong downturn of the premaxillary process of the maxilla

Species

Ajnabia odysseus Longrich et al., 2021

Type species

Named for the Greek hero and legendary sea voyager Odysseus, in reference to the oceanic dispersal believed to have brought this hadrosaur's ancestors to Africa.

Holotype
MHNM KHG 222 , Muséum d'Histoire Naturelle de Marrakech
Material
Partial left maxilla with teeth, fragments of right maxilla, partial left dentary
Horizon
upper Couche III Member, Phosphates of the Oulad Abdoun Basin Formation, Maastrichtian, Late Cretaceous , 72.2–66.0 million years ago
Locality
Sidi Chennane, Khouribga, Morocco

References

  1. Longrich, N. R.; Suberbiola, X. P.; Pyron, R. A.; Jalil, N. E. (2021). The first duckbill dinosaur (Hadrosauridae: Lambeosaurinae) from Africa and the role of oceanic dispersal in dinosaur biogeography. Cretaceous Research 120. Elsevier BV. doi:10.1016/j.cretres.2020.104678 longrich2021a
  2. Jones, B. (2026). The Princeton Encyclopedia of Dinosaurs: Ornithischians. Princeton University Press.

    Source of the mass and hip height estimates.

    jones2026a