Laplatasaurus (meaning "La Plata lizard", named for La Plata, Argentina) is a genus of sauropod dinosaur that lived during the Late Cretaceous in South America, with the holotype and only known specimen found in the Anacleto Formation.
Naming and description
The genus was named in 1927 by Friedrich von Huene, but without a description, so that it remained a
nomen nudum.
[Huene, F. von, 1927, "Sichtung der Grundlagen der Jetzigen Kenntnis der Sauropoden", Eclogae geologicae Helvetiae, 20: 444-470] In 1929 the
type species,
Laplatasaurus araukanicus, was described by Huene.
[Huene, F. von, 1929, Los Saurisquios y Ornithisquios de Cretaceo Argentino, Anales Museo de La Plata, 2nd series, v. 3, p. 1-196] The generic name refers to La Plata. The specific name is derived from the
Araucanos or
Mapuche. By accident Huene in 1929 also mentioned a "Laplatasaurus wichmannianus" but that was a
lapsus calami for
Antarctosaurus wichmannianus. In 1933 however, he and Charles Alfred Matley renamed
Titanosaurus madagascariensis to
Laplatasaurus madagascariensis.
[Huene, F. von, and Mately C. A., 1933, "The Cretaceous Saurischia and Ornithischia of the central provinces of India", Palaeontologia Indica, 21: 1-74] This last species is today commonly referred to the original
Titanosaurus.
Dinosaur egg from the Anacleto Formation that was previously assigned to Titanosaurus that may have instead been laid by Laplatasaurus
]]Huene based Laplatasaurus
on fragmentary material found in three locations in Argentina, in strata of the Anacleto Formation,Titanosaurus australis''. Huene never assigned a
holotype, but in 1979 José Fernando Bonaparte chose
MLP 26-306 as the
lectotype, a specimen consisting of a
tibia and a
fibula that perhaps originate from different individuals.
Huene assigned those fossils to Laplatasaurus that seemed to indicate a rather large yet at the same time elegantly built sauropod. The about long Laplatasaurus was perhaps similar to Saltasaurus. Osteoderms forming an armored plating on the back, have been referred to Laplatasaurus but the association is uncertain. These plates had much smaller ridges than those of Saltasaurus.
A Megaloolithus Dinosaur egg found in the Anacleto Formation in Auca Mahuevo, Argentina[ Megaloolithus at Fossilworks.org] that was once assigned to Titanosaurus may have instead been laid by Laplatasaurus.
Taxonomy
Huene placed
Laplatasaurus in the
Titanosauridae, which is still a common classification. In his 2003 review of South American titanosaurs, Jaime Eduardo Powell assigned
Laplatasaurus to
Titanosaurus, creating the new combination
Titanosaurus aurakanicus.
[Powell, J. E., 2003, "Revision of South American titanosaurid dinosaurs: palaeobiological, palaeobiogeographical and phylogenetic aspects", Records of the Queen Victoria Museum 111: 1-173] Others however, continued to treat
Laplatasaurus as valid genus separate from
Titanosaurus.
[Upchurch, P., Barrett, P.M. and Dodson, P. 2004. Sauropoda. In The Dinosauria, 2nd edition. D. Weishampel, P. Dodson, and H. Osmólska (eds.). University of California Press, Berkeley. , S. 259–322.][Salgado, L. & Coria, R. A. 2005. Sauropods of Patagonia: Systematic update and notes on Global Sauropod evolution. In. Thunder-Lizards. The Sauropodomorph Dinosaurs. Ed. V. Tidwell & K. Carpenter. Indiana University Press. Bloomington and Indianapolis. Indiana University Press430-453.]
A 2015 re-assessment of Laplatasaurus found it to be closely related to Bonitasaura, Futalognkosaurus, Mendozasaurus, and Uberabatitan. The genus was restricted to the lectotype, and the material from Rancho de Avila was assigned to cf. Bonitasaura sp.
