Open Paleo

Gonkoken

Alarcón-Muñoz et al., 2023 gon-KO-ken

Similar to a wild duck or swan; from the Aonikenk (Tehuelche) language of Patagonia

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

Gonkoken is an extinct genus of hadrosauroid ornithopod dinosaur from the Late Cretaceous Dorotea Formation of Chilean Patagonia. The genus contains a single species, Gonkoken nanoi, known from disarticulated bones of multiple individuals.

Diagnosis

  1. Scapula with an anteroventrally curved pseudoacromion process
  2. Ilium with a medioventrally and anteroposteriorly well-developed sacral crest extending posterior to the base of the postacetabular process
  3. Maxilla with a jugal articular surface bearing a prominent and caudally projecting dorsal tubercle, unlike Hadrosauridae
  4. Dentary with a short diastema, oblique mandibular symphysis, and fewer than 30 tooth positions not extending beyond the coronoid process
  5. Deltopectoral crest with a rounded laterodistal end extending less than 48% of total humerus length
  6. Tibia with a cnemial crest extending less than 50% of total bone length

Species

Gonkoken nanoi Alarcón-Muñoz et al., 2023

Type species

Named for Mario 'Nano' Ulloa, honored by the describing authors.

Holotype
CPAP 3054 , Instituto Antártico Chileno
Material
Right ilium; adult, as indicated by well-developed T-shaped cross section of preacetabular process with lateral and medial crests.
Horizon
upper Dorotea Formation, Maastrichtian, Late Cretaceous , 72.2–66.0 million years ago
Locality
Loma Koken, El Puesto, Magellan and the Chilean Antarctic, Chile

References

  1. Alarcón-Muñoz, J.; Vargas, A. O.; Püschel, H. P.; Soto-Acuña, S.; Manríquez, L.; Leppe, M.; Kaluza, J.; Milla, V.; Gutstein, C. S.; Palma-Liberona, J.; Stinnesbeck, W.; Frey, E.; Pino, J. P.; Bajor, D.; Núñez, E.; Ortiz, H.; Rubilar-Rogers, D.; Cruzado-Caballero, P. (2023). Relict duck-billed dinosaurs survived into the last age of the dinosaurs in subantarctic Chile. Science Advances 9(24). American Association for the Advancement of Science (AAAS). doi:10.1126/sciadv.adg2456 alarcón-muñoz2023a
  2. Jones, B. (2026). The Princeton Encyclopedia of Dinosaurs: Ornithischians. Princeton University Press.

    Source of the mass and hip height estimates, and the appearance features.

    jones2026a