Notohypsilophodon is based onUNPSJB — PV 942, a partial skeleton including four neck, seven back, four hip, and six tailvertebrae, rib fragments, a partial scapula (shoulder blade), partial coracoid, a humerus (upper arm bone), both ulnae, and most of a left leg (minus the foot) and a right fibula and astragalus. Because the neural arches are not fused to the bodies of the vertebrae, its describer, Rubén D. Martínez, regarded the individual as not fully grown. He found no evidence that it was an iguanodont, and instead assigned it to the more basal Hypsilophodontidae, which made it at the time the only South American hypsilophodont.1 A hypsilophodontid assignment was supported by Rodolfo Coria in a 1999 review of South American ornithopods,2 but a more recent review of basal ornithopods found the fossil remains to be too fragmentary for classification beyond Euornithopoda, a clade within Ornithopoda including the hypsilophodonts and iguanodonts.3
Paleobiology
As a hypsilophodontid or other basal ornithopod, Notohypsilophodon would have been a bipedalherbivore. Its size has not been estimated, but as most adult hypsilophodonts were 1-2 meters long (3.3-6.6 feet),3 this genus would probably have been of similar size.
References
^ Martínez, Rubén D. (1998). "Notohypsilophodon comodorensis, gen. et sp. nov., un Hypsilophodontidae (Ornithischia: Ornithopoda) del Cretacico Superior de Chubut, Patagonia central, Argentina" (in Spanish, with English abstract; English translation by Matthew C. Lamanna available at the Polyglot Paleontologist website). Acta Geologica Leopoldensia21 (46/47): 119–135.
^Coria, Rodolfo A. (1999). "Ornithopod dinosaurs from the Neuquén Group, Patagonia, Argentina: phylogeny and biostratigraphy", in Tomida, Yukimitsu; Rich, Thomas H.; and Vickers-Rich, Patricia (eds.): Proceedings of the Second Gondwanan Dinosaur Symposium, National Science Museum Monographs, 15. Tokyo: National Science Museum, 47-60.
^ abNorman, David B.; Sues, Hans-Dieter; Witmer, Larry M.; and Coria, Rodolfo A. (2004). "Basal Ornithopoda", in Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.): The Dinosauria, 2nd, Berkeley: University of California Press, 393-412. ISBN 0-520-24209-2.