Earlier this year, researchers revealed the discovery of a new titanosaur from Patagonia.  The dinosaur named Titanomachya gimenezi comes from northern Chubut Province in central Patagonia. Several titanosaur taxa have been reported from northern Patagonia, as well as few titanosaurs from southern Patagonia. However, titanosaurs from the end-Cretaceous of central Patagonia are poorly known. The fossil specimen represents an adult animal. It is described as a small-bodied saltasauroid. However, despite being small by titanosaur standards, it has been estimated that Titanomachya weighed around 8 tonnes (weight estimates range from 5.8 to 9.8 tonnes).

Titanomachya gimenezi life reconstruction. Picture credit: Gabriel Diaz.

Picture credit: Gabriel Diaz

Fossils from the La Colonia Formation

The fossils come from La Colonia Formation and the research team consisted of Agustín Pérez Moreno, Leonardo Salgado, José Luis Carballido, Alejandro Otero, and Diego Pol. These eminent researchers herald from a variety of Argentinian institutions including the Museo de La Plata (MLP), the Museo Paleontológico Egidio Feruglio (MEF) and the Fundación Félix de Azara-Universidad Maimónides.

Titanomachya gimenezi fossil excavation. Picture credit: Vincent Brusca.

Picture credit: Vincent Brusca

The strata in which the fossils were found date from the Upper Cretaceous (Maastrichtian faunal stage).  This indicates that Titanomachya gimenezi roamed this part of Gondwana around seventy million years ago.  The genus name is derived from the Titanomachy, a mythical battle fought by the Olympian gods against the Titans in Greek mythology.  In this battle, the Titans lost.  The name is appropriate and fitting since Titanomachya comes from the time when the titanosaurs were heading for extinction.  The species name honours the late Dr Olga Giménez.  Dr Giménez played a pivotal role in the study of vertebrate fossils found in central Patagonia.  She was the first palaeontologist to study the dinosaurs of the Chubut province.

Field team members excavating the fossils. Picture credit: Vincent Brusca.

Picture credit: Vincent Brusca

Studying the Fossil Material

More than fifteen scientists have been involved in the field work.  The excavation work was carried out over two years and the fossil material found consists of elements from the limbs along with fragments of ribs and a caudal vertebra.  Once exposed, the fossils were jacketed with burlap and plaster and sent to the MEF laboratories for preparation.

Skeletal reconstruction of Titanomachya gimenezi. The bones coloured blue represent the known fossil material. Picture credit: Gabriel Lio.

Picture credit: Gabriel Lio

This newly described titanosaur is the smallest known from central Patagonia.  Titanomachya (pronounced tie-tan-om-mack-ee-ah), may have measured around ten metres long when fully grown.  It was similar in size to Neuquensaurus australis and Saltasaurus loricatus, to which it was closely related.  The research team identified several unique autapomorphies which allowed them to confidently erect a new taxon.  For example, the astragalus (bone from the ankle), demonstrates unique morphology.  It shows intermediate traits between the Saltasauroidea titanosaurs and the Colossosauria clade of titanosaurs.  These autapomorphies highlight the significance of this discovery as it provides an evolutionary link between different types of sauropod.

Furthermore, phylogenetic studies have demonstrated that Titanomachya is a derived titanosaur. It is a member of the great Saltasauroidea lineage.

Titanomachya gimenezi fossils exposed on the surface. Picture credit: Vincent Brusca.

Picture credit: Vincent Brusca

Titanomachya gimenezi and the South America Titanosaur Biota

The La Colonia formation has also yielded the famous theropod Carnotaurus as well as other material.  Fossils representing other carnivorous dinosaurs have been discovered.  For instance, the recently described abelisaurid Koleken (K. inakayali).

To read more about Koleken: A New Abelisaurid from Southern Argentina.

In addition, the remains of ornithischian dinosaurs have been found.  However, Titanomachya gimenezi represents one of only a handful of defined taxa and the first sauropod known from this formation.  This discovery sheds light on the diversity of the region’s ecosystems at the very end of the Age of Dinosaurs.  Moreover, it provides crucial data regarding the composition of sauropod populations in Patagonia during the Maastrichtian.

The researchers postulate that distinct sauropod faunas existed in different parts of Patagonia and also in Brazil over the Campanian and Maastrichtian Epochs. In northern Patagonia, aeolosaurines and saltasaurines dominated, whilst in southern Patagonia, the sauropod biota mostly comprised colossosaurians and other large titanosaurs. In contrast, the less well-known sauropod fauna from central Patagonia seems to have consisted of small-bodied saltasauroids such as Titanomachya along with members of the aeolosaurini and derived eutitanosaurs.

Titanomachya gimenezi in its low-lying coastal habitat. Picture credit: Gabriel Diaz.

Picture credit: Gabriel Diaz

Further Research Planned

Summarising their research to date, the scientists suggest that Titanomachya provides a new perspective on the rich history of sauropods in Patagonia.  In addition, this unique specimen opens the door to future research that will explore the diversity and evolution of these amazing herbivores.

Everything Dinosaur acknowledges the assistance of corresponding author Dr Pérez Moreno CONICET (Consejo Nacional de Investigaciones Científicas y Técnicas), Buenos Aires, Argentina, in the compilation of this article.

The scientific paper: “A new titanosaur from the La Colonia Formation (Campanian-Maastrichtian), Chubut Province, Argentina” by Agustín Pérez-Moreno, Leonardo Salgado, José L. Carballido, Alejandro Otero and Diego Pol published in Historical Biology.

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