Open Paleo

Notohypsilophodon

Martínez, 1998 NOT-o-hip-si-LOF-o-don

From Greek 'notos' meaning 'south wind' (indicating its southern provenance in South America) combined with the genus name Hypsilophodon, indicating its similarity to that ornithopod.

100.5–93.9 million years ago Cenomanian, Late Cretaceous
Late Cretaceous stages

Notohypsilophodon is a genus of ornithopod dinosaur from the Late Cretaceous of Argentina. It was described as the only "hypsilophodont" known from South America, although this assessment is not universally supported, and Gasparinisaura is now believed to have been a basal euornithopod as well.

Under dispute

Notohypsilophodon was described as a hypsilophodontid (Martínez, 1998). Rozadilla and colleagues (2016) and Boyd (2015) recover it within Elasmaria, which Boyd places among the thescelosaurines; Madzia and colleagues (2017) instead recover it within Thescelosaurinae outside Elasmaria, and Ibiricu and colleagues (2014) find its position highly unstable.

Diagnosis

  1. Anteromedial bulge on the proximal extremity of the tibia
  2. Calcaneum with a pronounced posterodistal projection
  3. Distal tip of the sacral neural spine strongly projected posteriorly
  4. Sternal process of the coracoid markedly reduced

Species

Notohypsilophodon comodorensis Martínez, 1998

Type species

Named for Comodoro Rivadavia, the nearest city to the discovery site.

Holotype
UNPSJB-PV 942 , Universidad Nacional de la Patagonia San Juan Bosco
Material
Partial skeleton comprising four cervical, seven dorsal, four sacral, and six caudal vertebrae (all partial); a rib fragment; partial left scapula; right coracoid; right humerus; both ulnae; incomplete left femur; both tibiae; both fibulae; right astragalus; left calcaneum; and 13 pedal phalanges.
Horizon
lower Bajo Barreal Formation, Cenomanian, Late Cretaceous , 100.5–93.9 million years ago
Locality
28 km northeast of Buen Pasto, Chubut, Argentina

References

  1. Martínez, R. D. (1998). Notohypsilophodon comodorensis gen. et sp. nov. un Hypsilophodontidae (Ornitischia: Ornithopoda) del Cretácico Superior de Chubut, Patagonia central, Argentina [Notohypsilophodon comodorensis gen. et sp. nov., a Hypsilophodontidae (Ornithischia: Ornithopoda) from the Upper Cretaceous of Chubut, central Patagonia, Argentina]. Acta Geologica Leopoldensia 21(46/47): 119-135. martínez1998a
  2. Ibiricu, L. M.; Martínez, R. D.; Luna, M.; Casal, G. A. (2014). A reappraisal of Notohypsilophodon comodorensis (Ornithischia: Ornithopoda) from the Late Cretaceous of Patagonia, Argentina. Zootaxa 3786(4): 401-422. Magnolia Press. doi:10.11646/zootaxa.3786.4.1

    Restudy of the holotype providing an emended diagnosis; recovers Notohypsilophodon as a basal ornithopod, more basal than Gasparinisaura.

    ibiricu2014a
  3. Rozadilla, S.; Agnolín, F. L.; Novas, F. E.; Aranciaga Rolando, A. M.; Motta, M. J.; Lirio, J. M.; Isasi, M. P. (2016). A new ornithopod (Dinosauria, Ornithischia) from the Upper Cretaceous of Antarctica and its palaeobiogeographical implications. Cretaceous Research 57: 311-324. Elsevier BV. doi:10.1016/j.cretres.2015.09.009

    Recovered Notohypsilophodon within Elasmaria in Gondwanan ornithopod analysis.

    rozadilla2016a
  4. Madzia, D.; Boyd, C. A.; Mazuch, M. (2017). A basal ornithopod dinosaur from the Cenomanian of the Czech Republic. Journal of Systematic Palaeontology 16(11): 967-979. Informa UK Limited. doi:10.1080/14772019.2017.1371258

    Recovered Notohypsilophodon within Thescelosaurinae, outside Elasmaria.

    madzia2017a
  5. Jones, B. (2026). The Princeton Encyclopedia of Dinosaurs: Ornithischians. Princeton University Press.

    Treats Notohypsilophodon as an elasmarian.

    jones2026a
  6. Boyd, C. A. (2015). The systematic relationships and biogeographic history of ornithischian dinosaurs. PeerJ 3: e1523. PeerJ. doi:10.7717/peerj.1523

    Recovered Notohypsilophodon within Elasmaria, nested inside a broader Thescelosaurinae.

    boyd2015a