Open Paleo

Iberospinus

Mateus & Estraviz-López, 2022 eye-BEH-ro-SPY-nus

Iberian spine; from Iberia (the Iberian Peninsula, where it was found in Portugal) and Latin spina (spine), referring to its spinosaurid neural spines

125.8–121.4 million years ago Barremian, Early Cretaceous
Early Cretaceous stages

Iberospinus is an extinct genus of spinosaurid dinosaur from the Early Cretaceous (Barremian) Papo Seco Formation of Portugal. The genus contains a single species, I. natarioi, known from several assorted bones belonging to one individual. Iberospinus represents one of five known spinosaurid taxa from the Iberian Peninsula, the others being Camarillasaurus, Protathlitis, Riojavenatrix, and Vallibonavenatrix. It is important for its implications of the geographical origin of Spinosauridae and the suggested presence of potentially semi-aquatic lifestyle earlier in the evolution of this clade.

Under dispute

Iberospinus natarioi is a spinosaurid whose subfamily placement is unstable. The describing analysis (Mateus and Estraviz-López, 2022) recovers it as sister to the Baryonyx plus Suchomimus clade, outside both subfamilies but favoring baryonychine affinity; Barker and colleagues (2021) and Isasmendi and colleagues (2024) recover it as a baryonychine, whereas Rauhut and colleagues (2025) recover it as the basalmost spinosaurine.

Diagnosis

  1. Single foramen in the Meckelian sulcus (autapomorphic)
  2. Straight ventral edge of dentary (not upturned)
  3. Laminae present in pleurocoelic depression of medio-distal caudal vertebrae
  4. Scapula with straight anterior rim (acromion not protruding)
  5. Scapula with reduced acromial ridge
  6. Scapula with contact with coracoid occupying entire ventral surface
  7. Pubic apron thick along nearly entire pubis shaft
  8. Mound-like eminence in proximal lateral part of pubis

Species

Iberospinus natarioi Mateus & Estraviz-López, 2022

Type species

Named for Carlos Natário, the discoverer of the holotype.

Holotype
ML1190 , Museu da Lourinhã
Material
Anterior left dentary portion, dentary fragment, tooth, fragmentary tooth (×2), partial right scapula, dorsal neural arch (×2), dorsal vertebra, ribs (×4 fragments), pubis elements, calcaneum (×2), ungual pedal phalanx, caudal vertebrae (×12)
Horizon
Papo Seco Formation, Barremian, Early Cretaceous , 125.8–121.4 million years ago
Locality
Praia de Aguncheiras, Setúbal, Portugal

References

  1. Mateus, O.; Estraviz-López, D. (2022). A new theropod dinosaur from the early cretaceous (Barremian) of Cabo Espichel, Portugal: Implications for spinosaurid evolution. PLOS ONE 17(2): e0262614. Public Library of Science (PLoS). doi:10.1371/journal.pone.0262614 mateus2022a
  2. Barker, C. T.; Hone, D. W. E.; Naish, D.; Cau, A.; Lockwood, J. A. F.; Foster, B.; Clarkin, C. E.; Schneider, P.; Gostling, N. J. (2021). New spinosaurids from the Wessex Formation (Early Cretaceous, UK) and the European origins of Spinosauridae. Scientific Reports 11(1). Springer Science and Business Media LLC. doi:10.1038/s41598-021-97870-8

    New Wessex spinosaurid description recovered Iberospinus with baryonychine affinities.

    barker2021a
  3. Isasmendi, E.; Cuesta, E.; Díaz-Martínez, I.; Company, J.; Sáez-Benito, P.; Viera, L. I.; Torices, A.; Pereda-Suberbiola, X. (2024). Increasing the theropod record of Europe: a new basal spinosaurid from the Enciso Group of the Cameros Basin (La Rioja, Spain). Evolutionary implications and palaeobiodiversity. Zoological Journal of the Linnean Society 202(3). Oxford University Press (OUP). doi:10.1093/zoolinnean/zlad193

    New basal European spinosaurid study recovered Iberospinus as a baryonychine.

    isasmendi2024a
  4. Rauhut, O. W. M.; Canudo, J. I.; Castanera, D. (2025). Revision of the theropod dinosaur Camarillasaurus cirugedae from the Early Cretaceous (Barremian) of Teruel province, Spain. Palaeontologia Electronica 28(3): 1-67. doi:10.26879/1543

    Camarillasaurus revision's spinosaurid phylogeny recovered Iberospinus as basalmost spinosaurine.

    rauhut2025a