Eocene (Ypresian-Lutetian) mammals from Cerro Pan de Azúcar (Gaiman, Chubut Province, Argentina)

ABSTRACT

In this work, we present several new materials collected at the pink sandstone levels from the Las Flores Formation at the Cerro Pan de Azúcar (Gaiman, Chubut Province, Argentina) and compare them with taxa present in other localities of similar age. The Metatheria taxa described here are 1) the ‘Ameridelphia’ Sternbergiidae indet; 2) the Didelphimorphia Protodidelphis cf. mastodontoides and Guggenheimia glykeia sp. nov. (Protodidelphidae); 3) the Polydolopimorphia Pliodolops rothi and Pliodolops cf. kamektsen (Polydolopidae); and 4) the Microbiotheria Eomicrobiotherium diluculum sp. nov. (Microbiotheriidae). On the other hand, the Cingulata Dasypodidae is represented by the Astegotheriini Prostegotherium astrifer. This fauna shares more species with those occurring in the localities from Paso del Sapo than with any other early – middle Eocene localities. However, at the generic level, it shares several taxa with the Itaboraian fauna from Sao José de Itaboraí. Finally, the faunal associations from Pan de Azúcar, Paso del Sapo, Cañadón Hondo, and Bajo de la Palangana could be, at least in part, synchronous, representing locally the Riochican SALMA, with an age spanning from 51 to 45 Ma (early Ypresian- early Lutetian).

KEYWORDS:

• Paleogene
• Patagonia
• South America
• Mammalia
• Metatheria
• Cingulata

Acknowledgments

We want to thank Marián Tanuz (UBA), E. Ruigomez and M.E. Pérez (MEF) for letting us visit the collections under their care. A. Villafañe, M.E. Pérez, and M. Cárdenas for their help in the field. A.M. Baez for information regarding UBA fieltrip to Pan de Azúcar. M. Borelli and V. Ketzelman for their help with specific epithets.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the FONCyT [Fondo para la Investigación Científica y Tecnológica] under Grant PICT 2016- 0508 and Grant PICT 2019-3351 to LC; PICT 2019-03283 to FJG;PICT 2019-01650 and PICT-2020-SerieA-3832 to JMK; CONICET [Consejo Nacional de Investigaciones Científicas y Técnicas] under Grant PUE22920160100098 to LC; PIP 0150 to FJG and PIP 2021-2023 GI-11220200103010CO to JMK. UNLP [Universidad Nacional de La Plata] under grant UNLP-N 889 to MRC.