Open Paleo

Proa

McDonald et al., 2012 PRAU

From Spanish 'proa' meaning 'prow', alluding to the pointed shape of the animal's predentary bone.

113.2–100.5 million years ago Albian, Early Cretaceous
Early Cretaceous stages

Proa is a genus of basal iguanodont dinosaur from the Early Cretaceous Escucha Formation of Aragón, Spain. The type and only species, Proa valdearinnoensis, is known from fragmentary remains and represents an unusual hadrosauriform from the Albian stage.

Under dispute

Proa valdearinnoensis was recovered at the base of Hadrosauriformes by its describers (McDonald and colleagues, 2012), and most later analyses place it within that clade, as a basal hadrosauroid or close to Fukuisaurus or Iguanodon (Norman, 2015; Madzia and colleagues, 2019; Poole, 2022). Other analyses place it on the stem below Hadrosauriformes (Boyd and Pagnac, 2015; Bonsor and colleagues, 2023; Bertozzo and colleagues, 2025).

Diagnosis

  1. Predentary comes to a point at rostral margin with divergent lateral processes (autapomorphy)
  2. Dentary tooth row convex dorsally in lateral view
  3. Dentary tooth row extends caudal to base of coronoid process
  4. Platform between dentary tooth row and coronoid process base
  5. Coronoid process expanded along rostral and caudal margins
  6. Maxilla lacks rostrodorsal process
  7. Quadrate straight in lateral view
  8. Ilium with convex dorsal margin, non-pendant supraacetabular process, postacetabular process tapering without break in slope
  9. Cranial pubic process concave along dorsal margin without distal expansion

Species

Proa valdearinnoensis McDonald et al., 2012

Type species

Named for Val de Ariño, the traditional name for the coal mines near where the first fossils were found.

Holotype
AR-1/19 , Museo de la Fundación Conjunto Paleontológico de Teruel-Dinópolis
Material
Disarticulated but associated skull including premaxillae, partial maxillae, quadrates, supraorbitals, articulated braincase and skull roof, predentary, left dentary, partial right surangular, right dentary, and several unprepared postcranial bones.
Horizon
Escucha Formation, Albian, Early Cretaceous , 113.2–100.5 million years ago
Locality
AR-1, Santa María coal mine, Ariño, Teruel, Spain

References

  1. McDonald, A. T.; Espílez, E.; Mampel, L.; Kirkland, J. I.; Alcalá, L. (2012). An unusual new basal iguanodont (Dinosauria: Ornithopoda) from the Lower Cretaceous of Teruel, Spain. Zootaxa 3595(1). Magnolia Press. doi:10.11646/zootaxa.3595.1.3

    Named Proa and recovered it in a polytomy with Iguanodon and Hadrosauroidea at the base of Hadrosauriformes.

    mcdonald2012a
  2. Paul, G. S. (2024). The Princeton Field Guide to Dinosaurs (3rd ed.). Princeton University Press.

    Source of the body length and mass estimates.

    paul2024a
  3. Jones, B. (2026). The Princeton Encyclopedia of Dinosaurs: Ornithischians. Princeton University Press.

    Source of the hip height estimate, and the appearance features.

    jones2026a
  4. Madzia, D.; Jagt, J. W. M.; Mulder, E. W. A. (2019). Osteology, phylogenetic affinities and taxonomic status of the enigmatic late Maastrichtian ornithopod taxon Orthomerus dolloi (Dinosauria, Ornithischia). Cretaceous Research 108: 104334. Elsevier BV. doi:10.1016/j.cretres.2019.104334

    Recovered Proa within basal Hadrosauroidea in osteological and phylogenetic reassessment.

    madzia2019a
  5. Norman, D. B. (2015). On the history, osteology, and systematic position of the Wealden (Hastings group) dinosaur Hypselospinus fittoni (Iguanodontia: Styracosterna). Zoological Journal of the Linnean Society 173: 92-189. doi:10.1111/zoj.12193

    Recovered Proa at the base of Hadrosauriformes.

    norman2015a
  6. Poole, K. E. (2022). Phylogeny of iguanodontian dinosaurs and the evolution of quadrupedality. Palaeontologia Electronica 25(3): a30. doi:10.26879/702

    Recovered Proa with Fukuisaurus in an Iguanodontidae that includes Iguanodon.

    poole2022a
  7. Boyd, C. A.; Pagnac, D. C. (2015). Insight on the anatomy, systematic relationships, and age of the Early Cretaceous ankylopollexian dinosaur Dakotadon lakotaensis. PeerJ 3: e1263. PeerJ. doi:10.7717/peerj.1263

    Recovered Proa and Koshisaurus as non-hadrosauriform ankylopollexians.

    boyd2015b
  8. Bonsor, J. A.; Lockwood, J. A. F.; Leite, J. V.; Scott-Murray, A.; Maidment, S. C. R. (2023). The osteology of the holotype of the British iguanodontian dinosaur Mantellisaurus atherfieldensis. Monographs of the Palaeontographical Society 177(665): 1-63. doi:10.1080/02693445.2023.2234156

    Recovered Proa on the stem below Hadrosauriformes.

    bonsor2023a
  9. Bertozzo, F.; Camilo, B.; Araújo, R.; Manucci, F.; Kullberg, J. C.; Cerio, D. G.; de Carvalho, V. F.; Marrecas, P.; Figueiredo, S. D.; Godefroit, P. (2025). Cariocecus bocagei, a new basal hadrosauroid from the Lower Cretaceous of Portugal. Journal of Systematic Palaeontology 23(1). doi:10.1080/14772019.2025.2536347

    Recovered Proa as the sister of Lurdusaurus, outside the node containing Iguanodon.

    bertozzo2025a