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Evidence for advanced carnivory in fossil armadillos (Mammalia: Xenarthra: Dasypodidae)

Published online by Cambridge University Press:  08 April 2016

Sergio F. Vizcaíno  and
Gerardo De Iuliis
Sergio F. Vizcaíno
Affiliation:
Departamento Científico Paleontología de Vertebrados, Museo de La Plata. Paseo del Bosque s/n, 1900 La Plata, Argentina. E-mail: vizcaino@museo.fcnym.unlp.edu.ar
Gerardo De Iuliis
Affiliation:
Faculty of Community Services and Health Sciences, George Brown College, Toronto, Ontario M5A 1J5, Canada Department of Zoology, University of Toronto, 25 Harbord Street, Toronto, Ontario M5S 3G5, Canada. E-mail: gerry@zoo.utoronto.ca
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Abstract

The euphractine Macroeuphractus outesi, from the late Pliocene Chapadmalalan SALMA of Buenos Aires Province, Argentina, is one of the largest dasypodids known. Its skull preserves features remarkable for an armadillo. Its complete dental arcade and large caniniform teeth have received attention in the literature as indicative of scavenging behavior. This report considers the degree of carnivory within the context of the generally omnivorous feeding behavior of euphractine armadillos through morphological and biomechanical analyses. Morphological analyses reveal that the main differences between M. outesi and other euphractines are the enlargement of the cranium, particularly of the temporal fossa; more prominent muscular scars for origin of the temporalis muscle; a more expanded rostrum, particularly in dorsoventral height; a more powerful anterior dentition, especially in the great enlargement and caniniform modification of M2; and a deeper and more robust zygomatic arch. Biomechanical analyses indicate that the moment arm of the temporalis musculature is greater than that recorded for other armadillos. These analyses indicate that the temporalis was probably larger and played a more important role in Macroeuphractus than in other euphractines, a pattern that is more usual for carnivorous mammals. Combined with the second upper molariform, which is caniniform, the features suggest that Macroeuphractus occupied an extreme position in the carnivorous-omnivorous feeding behavior of euphractines. Its large size indicates that it could have easily preyed on hare-sized vertebrates.

Type
Articles
Information
Paleobiology , Volume 29 , Issue 1 , Winter 2003 , pp. 123 - 138
Copyright
Copyright © The Paleontological Society 

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