Skip to content Skip to navigation

Article: Snout shape and masticatory apparatus of the rodent-like mesotheriid ungulates (Notoungulata, Typotheria): exploring evolutionary trends in dietary strategies through ancestral reconstructions

Palaeontology - Vol. 64 - Cover Image
Publication: Palaeontology
Volume: 64
Part: 3
Publication Date: May 2021
Page(s): 385 408
Author(s): Marcos D. Ercoli, and Matías A. Armella
Addition Information

How to Cite

ERCOLI, M.D., ARMELLA, M.A. 2021. . Palaeontology, 64, 3, 385-408. DOI: /doi/10.1111/pala.12530

Author Information

  • Marcos D. Ercoli - Instituto de Ecorregiones Andinas (INECOA) Universidad Nacional de Jujuy CONICET, IdGyM Av. Bolivia, 1661 4600 San Salvador de Jujuy Jujuy Argentina
  • Matías A. Armella - Facultad de Ciencias Naturales e IML Instituto de Estratigrafía y Geología Sedimentaria Global (IESGLO-CONICET) Universidad Nacional de Tucumán Miguel Lillo 205 T4000JFE San Miguel de Tucumán Argentina
  • Matías A. Armella - Cátedra de Paleontología Facultad de Ciencias Exactas y Naturales Universidad Nacional de Catamarca Av. Belgrano 300 K4700AAP San Fernando del Valle de Catamarca Catamarca Argentina
  • Matías A. Armella - Instituto Superior de Correlación Geológica (INSUGEO-CONICET) Universidad Nacional de Tucumán Av. Presidente Perón s/n T4105XAY Horco Molle Tucumán Argentina

Publication History

  • Issue published online: 19 April 2021
  • Manuscript Accepted: 21 December 2020
  • Manuscript Received: 09 October 2020

Funded By

Agencia Nacional de Promoción Científica y Tecnológica. Grant Number: PICT-2018-01237
Consejo Nacional de Investigaciones Científicas y Técnicas. Grant Numbers: INECOA-PUE 2017, 22920170100027CO
Secretaría de Ciencia, Arte e Innovación Tecnológica, Universidad Nacional de Tucumán. Grant Number: PIUNT 2018 G-626

Online Version Hosted By

Wiley Online Library
Get Article: Wiley Online Library [Pay-to-View Access] |


Mesotheriidae were small to medium-sized native South American ungulates. Mesotheriids radiated from the early Oligocene epoch to the early–middle Pleistocene, in two subfamilies: Trachytheriinae and Mesotheriinae. Beyond the conspicuous fossil record, little is known about mesotheriid palaeobiology, and particularly, the dietary habits. To date, different studies suggest grazing habits, similar to some extant ungulates, but recent contributions are challenging this vision. Here, we explore dietary preferences in mesotheriids, focusing on food intake and oral processing strategies. We performed a shape analysis of the snout and reconstructed ancestral shapes to assess evolutionary trends within the clade. Also, we considered other morphological variables of the masticatory apparatus to perform a functional characterization. We recognized three snout configurations: Trachytherus, ‘Intermediate’ and Mesotherium morphotypes that can be associated with different food intake capabilities and, considering other morphological proxies, with the consumption of different food items. Taking into account palaeoenvironmental conditions, the evolution of the masticatory apparatus is interpreted in the context of a consumption gradient from coarse and tough foods (roots, tubers, tough leaves) to grasses. We propose that during the ecomorphological evolution of mesotheriids, an initial phase took place during the late Oligocene and Miocene, consisting of diversification and specialization for consumption of hard-to-break food items. A second phase began incipiently during the late Miocene, and became well-defined during the Pliocene and Pleistocene, characterized by an ecomorphological displacement towards grazing habits. Inferred dietary habits in Mesotheriidae could provide light on palaeoecological evolution and niche partitioning within South American herbivorous mammalian communities.

PalAss Go! URL: | Twitter: Share on Twitter | Facebook: Share on Facebook | Google+: Share on Google+