Notohypsilodon comodorensis
Notohypsilodon was a genus of neornithiscian dinosaur from the Late Cretaceous period. Its type species is N. comodorensis. The only specimen was found in the Bajo Barreal Formation in Chubut, Patagonia in 1985. The specimen in question has been identified as a juvenile due to the fact its neural arches are not fused to the body of the vertebrae.
Its autapomorphies include the femur's lateral margin of the greater trochanter is sigmoidal in shape, with a thick posterior edge and a very thin anterior edge, as well as, the proximal end of metatarsal IV has a thick and very well-developed posterior process that medially wraps metatarsal III.
The holotype consists of four neck, seven back, five hip, and six tail vertebrae, four rib fragments, a partial right coracoid, a partial left scapula, a right humerus, both ulnae, a right fibula and astragalus, a left femur, tibia, fibula, partial astragalus, and calcaneum; and thirteen phalanges.
Notohypsilodon was a small bipedal herbivore. It would most likely have been around 1-2 meters long. It was originally classified as a hypsilodont, hence its name, but was later found to be too fragmentary to be classified past Euornithopoda. A study in 2015 classified it as part of Elasmaria, a basal ornithischian clade.
Original paper: Martínez, Rubén D. (1998). "Notohypsilophodon comodorensis, gen. et sp. nov., un Hypsilophodontidae (Ornithischia: Ornithopoda) del Cretacico Superior de Chubut, Patagonia central, Argentina". Acta Geologica Leopoldensia (in Spanish and English). 21 (46/47): 119–135.
Wikipedia article: https://en.m.wikipedia.org/wiki/Notohypsilophodon