The Eocene armadillo Utaetus buccatus (Euphractinae) in the Guabirotuba Formation (Curitiba Basin) and carapace morphological implications

FERNANDO A. SEDOR; TABATA D. F. KLIMECK; ELISEU V. DIAS; EDISON V. OLIVEIRA ; MARTÍN R. CIANCIO; KIMBERLYM T. P. VIEIRA; LUIZ A. FERNANDES; RODOLFO J. ANGULO

JOURNAL OF SOUTH AMERICAN EARTH SCIENCES

PERGAMON-ELSEVIER SCIENCE LTD

Lugar: Amsterdam; Año: 2022 vol. 114 p. 1 - 15

0895-9811

The Guabirotuba Formation belongs to a small sedimentary basinlocated in the southernmost portion of the Cenozoic continental rift system ofsoutheastern Brazil. In this unit was recognized the Guabirotuba Fauna fromEocene, that includes several cingulates such as Machlydotherium,Proeocoleophorus, Parutaetus, Meteutatus, Utaetus and an indeterminatedAstegotheriini. The genus Utaetus in the Guabirotuba Fauna is confirmed bypresence of Utaetus buccatus based on the specimen MCN.P.1231 andreinforce the Barrancan Age for the Guabirotuba Formation. In this study weanalyzed numerous osteoderms associated to an individual, representing mostof the external morphological diversity among fixed, semi-movable and movableosteoderms. Morphological features are described for fixed and movableosteoderms as well as, for the first time, for the semi-movable osteoderms.Features of some semi-movable osteoderms indicate the presence of somekind of pectoral buckler on Utaetus buccatus. The known geographicdistribution of the genus Utaetus includes Argentinian Patagonia, Northwest ofArgentina, and South of Brazil. The geographic distribution of the speciesUtaetus buccatus, previously restricted to Argentinian Patagonia, is hereexpanded to lower latitudes during the middle Eocene, which allow to infer thatthe species distribution was wider than previously thought.