title: A new sauropod dinosaur from the Early Cretaceous of Tunisia with extreme avian-like pneumatization.
abstract: Recent interpretations of the postcranial anatomy of sauropod dinosaurs differ about pneumatic features supporting an avian-like ventilatory system; the most conservative workers reject most postcranial pneumatizations as being unambiguous evidence of abdominal air sacs. Here we describe the first articulated dinosaur skeleton from Tunisia and refer it to a new rebbachisaurid sauropod, Tataouinea hannibalis gen. et sp. nov. The Tunisian specimen shows a complex pattern of caudosacral and pelvic pneumatization--including the first report of an ischial pneumatic foramen among Dinosauria--strongly supporting the presence of abdominal air sacs. Character optimization among Rebbachisauridae indicates that in the caudal vertebrae, pneumatization of the neural arches preceded that of the centra; in the pelvis, pneumatization of the bones adjacent to the sacrum preceded that of more distal elements. Tataouinea was more closely related to European nigersaurines than to otherwise Gondwanan rebbachisaurids; this supports an Afro-European route for rebbachisaurid dispersal.
authors.affiliation: Dipartimento di Scienze Biologiche, Geologiche e Ambientali, Alma Mater Studiorum, Università di Bologna, Via Zamboni 67, 40126 Bologna, Italy. federico.fanti@unibo.it
authors.forename: Federico
authors.initials: F
authors.lastname: Fanti
authors.forename: Andrea
authors.initials: A
authors.lastname: Cau
authors.forename: Mohsen
authors.initials: M
authors.lastname: Hassine
authors.forename: Michela
authors.initials: M
authors.lastname: Contessi
mesh_terms: D063147:Animal Distribution; D000818:Animals; D005075:Biological Evolution; D001717:Birds / Q000033:anatomy & histology / Q000502:physiology; D001842:Bone and Bones / Q000033:anatomy & histology* / Q000502:physiology; D025061:Dinosaurs / Q000033:anatomy & histology* / Q000145:classification / Q000502:physiology; D005580:Fossils; D010163:Paleontology; D010802:Phylogeny; D014416:Tunisia