title: A complete skull of an early cretaceous sauropod and the evolution of advanced titanosaurians.
abstract: Advanced titanosaurian sauropods, such as nemegtosaurids and saltasaurids, were diverse and one of the most important groups of herbivores in the terrestrial biotas of the Late Cretaceous. However, little is known about their rise and diversification prior to the Late Cretaceous. Furthermore, the evolution of their highly-modified skull anatomy has been largely hindered by the scarcity of well-preserved cranial remains. A new sauropod dinosaur from the Early Cretaceous of Brazil represents the earliest advanced titanosaurian known to date, demonstrating that the initial diversification of advanced titanosaurians was well under way at least 30 million years before their known radiation in the latest Cretaceous. The new taxon also preserves the most complete skull among titanosaurians, further revealing that their low and elongated diplodocid-like skull morphology appeared much earlier than previously thought.
authors.affiliation: Museu de Zoologia da Universidade de São Paulo, São Paulo, Brazil. hzaher@usp.br
authors.forename: Hussam
authors.initials: H
authors.lastname: Zaher
authors.forename: Diego
authors.initials: D
authors.lastname: Pol
authors.forename: Alberto B
authors.initials: AB
authors.lastname: Carvalho
authors.forename: Paulo M
authors.initials: PM
authors.lastname: Nascimento
authors.forename: Claudio
authors.initials: C
authors.lastname: Riccomini
authors.forename: Peter
authors.initials: P
authors.lastname: Larson
authors.forename: Rubén
authors.initials: R
authors.lastname: Juarez-Valieri
authors.forename: Ricardo
authors.initials: R
authors.lastname: Pires-Domingues
authors.forename: Nelson Jorge
authors.initials: NJ
authors.lastname: da Silva
authors.forename: Diógenes de Almeida
authors.initials: Dde A
authors.lastname: Campos
mesh_terms: D000366:Age Determination by Teeth / Q000662:veterinary; D000818:Animals; D044822:Biodiversity; D005075:Biological Evolution; D001938:Brazil; D003393:Cranial Sutures / Q000033:anatomy & histology; D025061:Dinosaurs / Q000033:anatomy & histology* / Q000145:classification; D005580:Fossils; D008954:Models, Biological; D010163:Paleontology; D010802:Phylogeny; D012886:Skull / Q000033:anatomy & histology*