Gonkoken nanoi Alarcón-Muñoz et al., 2023 (new genus and species)
(Select bones and schematic skeletal of Gonkoken nanoi [scale bars = 50 mm for B–G, J, K–N, Q, S, and V–X, and 100 mm for H, I, O, P, R, T, and U], with preserved bones in white, from Alarcón-Muñoz et al., 2023)
Meaning of name: Gonkoken = duck/swan-like [in Tehuelche]; nanoi = for Mario “Nano” Ulloa [discoverer of dinosaur bones at the site where the original fossils were found]
Age: Late Cretaceous (Maastrichtian), between 70.5–71.7 million years ago
Where found: Dorotea Formation, Magallanes, Chile
How much is known: Numerous bones including parts of the skull, limbs, hips, and vertebral column. It is unknown whether any of these bones belonged to the same individuals, though at least three individuals are represented.
Notes: Gonkoken was a hadrosauroid, closely related to but not a member of the “core group” of duck-billed dinosaurs (hadrosaurids). All other hadrosauroids previously named from South America were true hadrosaurids. In fact, prior to the discovery of Gonkoken, non-hadrosaurid hadrosauroids near the end of the Cretaceous were not known from the Americas.
However, reexamination of supposed hadrosaurid fossils from Southern Patagonia and Antarctica suggests that these may also be remains of non-hadrosaurid hadrosauroids. It might have been that hadrosaurids (which probably originated in the Northern Hemisphere) never made it to the southern reaches of South America prior to the end-Cretaceous mass extinction, allowing other types of hadrosauroids to persist there in the absence of competition.
Reference: Alarcón-Muñoz, J., A.O. Vargas, H.P. Püschel, S. Soto-Acuña, L. Manríquez, M. Leppe, J. Kaluza, V. Milla, C.S. Gutstein, J. Palma-Liberona, W. Stinnesbeck, E. Frey, J.P. Pino, D. Bajor, E. Núñez, H. Ortiz, D. Rubilar-Rogers, and P. Cruzado-Caballero. 2023. Relict duck-billed dinosaurs survived into the last age of the dinosaurs in subantarctic Chile. Science Advances 9: eadg2456. doi: 10.1126/sciadv.adg2456
