Open Paleo

Notoceratops

Tapia, 1919 not-o-SEH-ruh-tops Nomen dubium

From Greek 'notos' (southern), 'keras' (horn), and 'ops' (face); meaning 'southern horned face', referring to its discovery in the southern part of South America.

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

Notoceratops is a dubious genus of extinct ornithischian dinosaur. The genus was described based on an incomplete, toothless left dentary (now lost) from the Late Cretaceous of Patagonia (in Argentina), probably dating to the Campanian or Maastrichtian. Initially classified as a putative ceratopsian found in the Lago Colhué Huapi Formation, the lost fragmentary holotype precludes confident referral of this taxon within ornithischians, with some researchers suggesting that it belongs to a hadrosaur instead.

Under dispute

Tapia (1919) described Notoceratops bonarellii on an incomplete dentary, now lost (Brett-Surman, 1989), as a ceratopsid, and Bonaparte (1984) and Brett-Surman (1989) keep it ceratopsian. Powell (2003) raises the possibility that it belongs to a hadrosaur, and recent work hedges: Ibiricu and colleagues (2019) call it the supposed ceratopsian and Bandeira and colleagues (2024) list it with a query. It is treated as a nomen dubium at Cerapoda incertae sedis.

Species

Notoceratops bonarellii Tapia, 1919 Nomen dubium

Type species

Named for Guido Bonarelli (1871-1951), who advised Augusto Tapia in Tapia's study of the find.

Holotype
Not catalogued , División de Paleontología de Vertebrados del Museo de Ciencias Naturales y Universidad Nacional de San Juan (lost)
Material
Incomplete left dental (lower jaw fragment), broken posteriorly and along medial half, with tooth row and Meckelian cartilage canal; coronoid process partially preserved
Horizon
Lago Colhué Huapi Formation, Maastrichtian, Late Cretaceous , 72.2–66.0 million years ago
Locality
the bluffs northwest of Lago Colhué Huapí, in the vicinity of the source of the Río Chico, Chubut, Argentina None of the papers cited for this taxon assigns the holotype to a formation. Casal and colleagues place Tapia's find on the Río Chico in southern Chubut, where the only Cretaceous continental unit exposed is the interval they later removed from the Bajo Barreal to erect the Lago Colhué Huapi.

References

  1. Tapia, A. (1919). Una mandibula de Dinosaurioa procedente de Patagonia [A dinosaur mandible from Patagonia]. Physis, Revista de la Sociedad Argentina de Ciencias Naturales 4: 369-370.

    Names Notoceratops bonarellii in a brief note, without a full description.

    tapia1919a
  2. Huene, F. V. (1929). Los saurisquios y ornitisquios del Cretáceo Argentino [The Saurischians and Ornithischians of the Argentine Cretaceous]. Anales del Museo de La Plata, series 2 3: 1-196.

    In Spanish. Provides the description of Notoceratops bonarellii (named by Tapia, 1919).

    huene1929a
  3. Casal, G.; Martínez, R. D.; Luna, M.; Sciutto, J. C.; Lamanna, M. C. (2007). Aeolosaurus colhuehuapensis sp. nov. (Sauropoda, Titanosauria) de la Formación Bajo Barreal, Cretácico superior de Argentina. Revista Brasileira de Paleontologia 10(1): 53-62. Sociedade Brasileira de Paleontologia. doi:10.4072/rbp.2007.1.05 casal2007a
  4. Casal, G. A.; Allard, J. O.; Foix, N. (2015). Análisis estratigráfico y paleontológico de afloramientos del Cretácico Superior en la cuenca del Golfo San Jorge: propuesta de nueva unidad litoestratigráfica para el Grupo Chubut. Revista de la Asociación Geológica Argentina 72(1): 81-99. casal2015a
  5. Bonaparte, J. F. (1984). I dinosauri dell'Argentina [. Sulle Orme dei Dinosauri 125-143. Erizzo Editrice, Esplorazioni e Ricerche.

    Finds the dentary's characters strongly indicative of Ceratopsidae.

    bonaparte1984a
  6. Brett-Surman, M. K. (1989). A revision of the Hadrosauridae (Reptilia: Ornithischia) and their evolution during the Campanian and Maastrichtian. 1-272. Doctoral thesis, The George Washington University.

    Reports the holotype lost and keeps the genus ceratopsian, rejecting a hadrosaurid assignment as circular.

    brett-surman1989a
  7. Powell, J. E. (2003). Revision of South American Titanosaurid dinosaurs: palaeobiological, palaeobiogeographical and phylogenetic aspects. Records of the Queen Victoria Museum 111: 1-173.

    Raises the possibility that the illustrated dentary belongs to a hadrosaur.

    powell2003a
  8. Ibiricu, L. M.; Casal, G. A.; Martínez, R. D.; Luna, M.; Canale, J. I.; Álvarez, B. N.; González Riga, B. (2019). A new ornithopod dinosaur (Dinosauria: Ornithischia) from the Late Cretaceous of central Patagonia. Cretaceous Research 98: 276-291. Elsevier BV. doi:10.1016/j.cretres.2019.02.001

    Calls Notoceratops the supposed ceratopsian and notes the loss of the holotype.

    ibiricu2019a
  9. Bandeira, K. L. N.; Navarro, B. A.; Pêgas, R. V.; Brilhante, N. S.; Brum, A. S.; de Souza, L. G.; da Silva, R. C.; Gallo, V. (2024). A reassessment of the historical fossil findings from Bahia State (Northeast Brazil) reveals a diversified dinosaur fauna in the Lower Cretaceous of South America. Historical Biology 37(3): 548-589. Informa UK Limited. doi:10.1080/08912963.2024.2318406

    Lists Notoceratops bonarellii with a query under Ceratopsia.

    bandeira2024a