Arackar licanantay gen. et sp. nov. a new lithostrotian (Dinosauria, Sauropoda) from the Upper Cretaceous of the Atacama Region, northern Chile

A new lithostrotian sauropod, Arackar licanantay gen. et sp. nov. is described based on a partial skeleton from the Upper Cretaceous (CampanianeMaastrichtian) beds of the Hornitos Formation, Atacama Re-gion, northern Chile. The holotype consists of axial (cervical and dorsal vertebrae) and appendicular (humerus, femur and ischium) elements of a sub-adult specimen (ca. 6.3 m long). Autapomorphies characterizing this new titanosaur include: middle neural arches with wide and tall cen-troprezygapophyseal fossa + parapophyseal centroprezygapophyseal fossa (cprf + pacprf) extending on the entire anterior faces of the pedicles, but not above the neural canal, and reduced spinopostzyga-pophyseal laminae, shorter than the postzygapophyseal facet length. A phylogenetic analysis based on a data matrix of 87 taxa and 405 characters recovered Arackar as a derived lithostrotian titanosaur, placing it in a clade that includes Rapetosaurus + (Arackar + Isisaurus). This is the third dinosaur named from Chile and the third titanosaur from the western side of the Andes in South America. (c) 2021 Elsevier Ltd. All rights reserved.