Tuesday, May 20, 2014

[Paleontology • 2014] Leinkupal laticauda • A Diplodocid Sauropod Survivor from the Early Cretaceous of South America (Bajada Colorada Formation of Neuquén Province, Patagonia, Argentina)

The South American dinosaur Leinkupal laticauda uses its whiplike tail to fend off predators
illustration: Jorge Antonio Gonzalez 


Diplodocids are by far the most emblematic sauropod dinosaurs. They are part of Diplodocoidea, a vast clade whose other members are well-known from Jurassic and Cretaceous strata in Africa, Europe, North and South America. However, Diplodocids were never certainly recognized from the Cretaceous or in any other southern land mass besides Africa. Here we report a new sauropod, Leikupal laticauda gen. et sp. nov., from the early Lower Cretaceous (Bajada Colorada Formation) of Neuquén Province, Patagonia, Argentina. This taxon differs from any other sauropod by the presence of anterior caudal transverse process extremely developed with lateroventral expansions reinforced by robust dorsal and ventral bars, very robust centroprezygapophyseal lamina in anterior caudal vertebra and paired pneumatic fossae on the postzygapophyses in anterior-most caudal vertebra. The phylogenetic analyses support its position not only within Diplodocidae but also as a member of Diplodocinae, clustering together with the African form Tornieria, pushing the origin of Diplodocoidea to the Middle Jurassic or even earlier. The new discovery represents the first record of a diplodocid for South America and the stratigraphically youngest record of this clade anywhere.

Systematic Paleontology

Dinosauria Owen, 1842

Saurischia Seeley, 1888
Sauropoda Marsh, 1878

Diplodocoidea Marsh, 1884
Flagellicaudata Harris & Dodson, 2004

Diplodocidae Marsh, 1884
Diplodocinae Marsh, 1884; Janensch, 1929

Leinkupal laticauda gen. et sp. nov.

Etymology: From lein, vanishing, and kupal, family. These are Mapudungun words, the language of the Mapuche Native American nation that inhabits northwestern Patagonia. The terms refer to the record of the last known representative of the family Diplodocidae. Meanwhile, lati, from latus, wide, and cauda, tail, in Latin words, refer to the broad tail evidenced by the lateral extension of the transverse processes in proximal caudal vertebrae.

Holotype: MMCH-Pv 63-1 (Museo Municipal “Ernesto Bachmann,” Villa El Chocón, Neuquén,), includes one anterior caudal vertebra (Caudal 7, see Description and comparisons below).

Pablo A. Gallina, Sebastián Apesteguía, Alejandro Haluza, Juan I. Canale. 2014. A Diplodocid Sauropod Survivor from the Early Cretaceous of South America. PLoS ONE. 2014; 9 (5): e97128 DOI: http://dx.doi.org/10.1371/journal.pone.0097128

Unique long-necked dinosaur unearthed in Argentina