[D] Titanosaurus robustus
Cretaceous Late Maastrichtian
Saurischia Sauropodomorpha Sauropoda Titanosauria
Rio Colorado Formation or Allen Fm., Provincia de Neuquen; Provincia de Rio Negro, Argentina
Saltasaurus (Bonaparte & Powell, 1980) = Microcoelus (Lydekker, 1893) Loricosaurus (Huene, 1929)
Saltasaurus > Saltasaurus loricatus (Bonaparte & Powell, 1980) > Saltasaurus robustus (Huene, 1929) = Titanosaurus robustus (Huene, 1929)
Saltasaurus > Saltasaurus australis (Lydekker, 1893) = Titanosaurus australis (Lydekker, 1893) >> Microcoelus patagonicus (Lydekker, 1893) Loricosaurus scutatus (Huene, 1929) Titanosaurus nanus (Lydekker, 1893)
Part of: Bonaparte, J. F. and Z. Gasparini. 1979. Los saurópodos de los grupos Neuquén y Chubut, y sus relaciones cronologicas. Actas del VII Congreso Geológico Argentino, Neuquén 2:393-406. [The sauropods of the Neuquén and Chubut groups and their chronological relations]
Translated by Jeffrey A. Wilson, Museum of Paleontology, University of Michigan, January 2003.
Titanosaurus robustus Huene 1929. An. Mus. La Plata, Paleont. III, 2nd series, pp. 48-53, figs. 11, 12; pls. 18-21.
M.L.P. 26-250 right ulna (C.S. 1095); M.L.P. 26-251 left ulna (C.S. 1094); M.L.P. 26-254 left radius (C.S. 1171); M.L.P. 26-259 left femur (C.S. 1480). The initials “C.S.” refer to Cinco Saltos, their origin as figured by Huene (1929).
Cinco Saltos, Río Negro Province. Huene (op. cit., 5) mentioned that “…the site was situated on the railway line north of Cipolletti, in the valley of the Río Neuquén”. This origin is not very precise.
Stratigraphic and chronological origin
Neuquén Group, Río Colorado or Allen Formation. Pre-Maastrichtian Senonian.
Important quantity of postcranial remains from Cinco Saltos (in majority) and Rancho de Avila. In Cinco Saltos, material of T. australis and T. robustus are encountered. Huene (op. cit.:48) considered that the cervical and dorsal vertebrae of C.S. of the Series 2 (op. cit.: 25) correspond to T. robustus.
Geographic, Stratigraphic, and Chronologic origin of the assigned material
1. Cinco Saltos, Neuquén Province, Neuquén Group, Río Colorado or Allen Formation. Pre-Maastrichtian Senonian.
2. Rancho de Avila (Alamitos), Río Negro Province, Neuquén Group, Río Colorado Formation. Pre-Maastrichtian Senonian.
The lack of a holotype in the descriptions of Huene has imposed us to designate a lectotype, based on four skeletal pieces that apparently pertain to the same individual. With the evidence available to us it should be admitted that T. robustus is a distinct species from Titanosaurus australis.
The differences are appreciated especially in the robustness of the ulna and in the distinguishing characters listed by Huene (op. cit.: 49-50) referring to the ulna and radius, which are in general valid. Also the femur of T. robustus, with a more prominent and defined greater trochanter than in Titanosaurus australis, is an element that confirms the validity of the species. It is important to emphasize, nonetheless, that the knowledge of the genus Titanosaurus, registered in Europe, India, and South America is far from being complete and satisfactory.
For this it should been interpreted that the diverse species that it integrates may or may not be confirmed the day that new material demonstrates the ranges of morphological variation. T. robustus has been recorded only in two localities in the Neuquén Group: Cinco Saltos and Rancho de Avila, both in Río Negro Province. Until, it has not been registered in the Chubut Group.
Source: Polyglot Paleontologist