Wednesday, April 21, 2021

[Paleontology • 2021] Arackar licanantay • A New Lithostrotian (Dinosauria, Sauropoda) from the Upper Cretaceous of the Atacama Region, northern Chile

 Arackar licanantay 
Rubilar-Rogers, Vargas, Riga, Soto-Acuña, Alarcón-Muñoz, Iriarte-Díaz, Arévalo & Gutstein, 2021

Arackar licanantay corresponds to the third species of dinosaur named in Chile.
 • Arackar licanantay represents a small subadult individual, with an estimated length of 6.3 m.
 • Arackar licanantay represents the most complete sauropod dinosaur recorded in the south Pacific margin of South America.

A new lithostrotian sauropod, Arackar licanantay gen. et sp. nov. is described based on a partial skeleton from the Upper Cretaceous (Campanian–Maastrichtian) beds of the Hornitos Formation, Atacama Region, 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 centroprezygapophyseal fossa + parapophyseal centroprezygapophyseal fossa (cprf + pacprf) extending on the entire anterior faces of the pedicles, but not above the neural canal, and reduced spinopostzygapophyseal 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.
Keywords: Titanosauria, Lithostrotia, Atacama region, Late cretaceous

 Arackar licanantay gen. et sp. nov.



 David Rubilar-Rogers, Alexander O. Vargas, Bernardo González Riga, Sergio Soto-Acuña, Jhonatan Alarcón-Muñoz, José Iriarte-Díaz, Carlos Arévalo and Carolina S. Gutstein. 2021. Arackar licanantay gen. et sp. nov. A New Lithostrotian (Dinosauria, Sauropoda) from the Upper Cretaceous of the Atacama Region, northern Chile. Cretaceous Research. 124, 104802. DOI: 10.1016/j.cretres.2021.104802