title: An Unexpected Early Rhabdodontid from Europe (Lower Cretaceous of Salas de los Infantes, Burgos Province, Spain) and a Re-Examination of Basal Iguanodontian Relationships.
abstract: Disarticulated and incomplete remains from a new diminutive ornithopod are described. They come from the Cameros Basin in the north of Spain and were collected from the red clays of the Castrillo de la Reina Formation, ranging from Upper Barremian to Lower Aptian. The new ornithopod described here is slender and one of the smallest ever reported. An up-to-date phylogenetic analysis recovers this taxon as a basal iguanodontian. Its unique combination of characters makes it more derived than slender ornithopods like Hyphilophodon and Gasparinisaura, and bring very interesting insights into the basal iguanodontian phylogeny. Though possessing a minimum of three premaxillary teeth, this taxon also bears an extensor ilio-tibialis groove on the distal part of its femur. Moreover, its dentary and maxillary teeth are unique, remarkably similar to those regarded as having a "rhabdomorphan" affinity. This unknown taxon is suggested to be a stem taxon within Rhabdodontidae, a successful clade of basal iguanodonts from the Late Cretaceous of Europe. The Gondwanan ornithopods share the strongest affinities with this family, and we confirm Muttaburrasaurus as a sister taxon of the Rhabdodontidae within a newly defined clade, the Rhabdodontomorpha.
authors.affiliation: Grupo Aragosaurus-IUCA, Área de Paleontología, Facultad de Ciencias, Universidad de Zaragoza, Pedro Cerbuna 12, 50009 Zaragoza, Spain.
authors.forename: Paul-Emile
authors.initials: PE
authors.lastname: Dieudonné
authors.affiliation: Réserve Naturelle Nationale Sainte-Victoire, Conseil Départemental des Bouches-du-Rhône, 52 avenue de Saint-Just, 13256 Marseille Cedex 20, France.
authors.forename: Thierry
authors.initials: T
authors.lastname: Tortosa
authors.affiliation: Museo de Dinosaurios de Salas de los Infantes and Colectivo Arqueológico-Paleontológico Salense (CAS), Plaza Jesús Aparicio 9, 09600 Salas de los Infantes, Burgos, Spain.
authors.forename: Fidel
authors.initials: F
authors.lastname: Torcida Fernández-Baldor
authors.affiliation: Grupo Aragosaurus-IUCA, Área de Paleontología, Facultad de Ciencias, Universidad de Zaragoza, Pedro Cerbuna 12, 50009 Zaragoza, Spain.
authors.forename: José Ignacio
authors.initials: JI
authors.lastname: Canudo
authors.affiliation: CONICET-Instituto de Investigación en Paleobiología y Geología, Universidad Nacional de Río Negro, General Roca 1242, 8332 Fisque Menuco (General Roca), Río Negro, Argentina.
authors.forename: Ignacio
authors.initials: I
authors.lastname: Díaz-Martínez
mesh_terms: D000818:Animals; D001842:Bone and Bones / Q000033:anatomy & histology; D002138:Calibration; D025061:Dinosaurs / Q000033:anatomy & histology*; D005843:Geography; D007091:Image Processing, Computer-Assisted; D010802:Phylogeny; D013030:Spain; D013997:Time Factors