Friday, December 22, 2023

[Paleontology • 2020] Tralkasaurus cuyi • A New Abelisaurid (Ceratosauria: Abelisauridae) from the Huincul Formation (Cenomanian-Turonian; Upper Cretaceous) of Río Negro Province, Argentina


Tralkasaurus cuyi 
 Cerroni, Motta, Agnolín, Aranciaga Rolando, Brissón Egli & Novas, 2020


Highlights: 
• We describe a new species of Abelisauride from the Huincul Formation (Cenomanian-Turonian), Rio Negro province, Patagonia, Argentina.
• Tralkasaurus cuyi nov. gen. et sp. constitutes a new form of medium-sized abelisaurid.
• The phylogenetic analysis resulted in the nesting of Tralkasaurus as a basal abelisaurid.
• The new abelisaurid affords new evidence regarding small to medium-sized abelisaurids from Patagonia.

Abstract
The record of abelisaurids in South America, particularly Argentina is relatively abundant. However, abelisaurid diversity is far from being well-known. Huincul Formation has yielded diverse theropod remains, including the abelisaurids Ilokelesia and Skorpiovenator. The aim of the present contribution is to describe a new abelisaurid coming from the Upper Section of the Huincul Formation (Cretaceous; Cenomanian-Turonian) at the Violante Farm fossil site, Río Negro province, northern Patagonia, Argentina. The new taxon described in this contribution is represented by an incomplete specimen including well-preserved maxilla and dorsal vertebrae, and distorted pelvic girdle and caudal and sacral vertebrae. Its size, much smaller than large abelisaurids as Abelisaurus and Carnotaurus indicates that the new taxon probably occupied a different ecological niche within the carnivoran guild.

Keywords: Abelisauridae, Upper Cretaceous, Río Negro province, Patagonia, Argentina





Systematic paleontology

Theropoda Marsh 1881
Ceratosauria Marsh, 1884

Abelisauroidea Bonaparte, 1991.
Abelisauridae Bonaparte and Novas, 1985.

Tralkasaurus cuyi gen. et sp. nov.

Holotype. MPCA-Pv 815 is represented by associated material including a right maxilla, distorted and incomplete dorsal, sacral and caudal vertebrae, cervical ribs, and pubis (Fig. 1).

Etymology. Tralka, means thunder in Mapudungun language, saurus means lizard in Ancient Greek; cuyi, ...

Conclusions: 
Here we described the new genus and species Tralkasaurus cuyi from Huincul Formation (Cenomanian-Turonian) beds. This new abelisaurid has a relatively small body size, as inferred from available bones. The size of Tralkasaurus contrasts with that of typical abelisaurids such as Abelisaurus and Carnotaurus, indicating that it would occupy a different ecological niche.

Furthermore, Tralkasaurus together with an unnamed abelisaurid from Cenomanian beds described by Canale et al. (2016) increases ...


 M. A. Cerroni, M. J. Motta, F. L. Agnolín, A. M. Aranciaga Rolando, F. Brissón Egli and F. E. Novas. 2020. A New Abelisaurid from the Huincul Formation (Cenomanian-Turonian; Upper Cretaceous) of Río Negro Province, Argentina. Journal of South American Earth Sciences. 98; 102445. DOI: 10.1016/j.jsames.2019.102445