New morphological data and phylogenetic position of the rare short-tailed opossum Monodelphis ronaldi (Didelphimorphia: Didelphidae) with new records

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Monodelphis ronaldi is a short-tailed opossum currently known only by the holotype captured in Madre de Dios, Peru. The relationships of this species with other congeners are unknown, although it has been hypothesized to belong to the subgenus Mygalodelphys. Here, we report six additional specimens of M. ronaldi from the Alto Purús, Ucayali department, Peru, extend the range of the species about 240 km eastward, examine ontogenetic variation, and analyze its phylogenetic relationships using sequences of the mitochondrial Cytochrome-b gene. Our analyses recovered M. ronaldi as the sister species of M. handleyi, confirming its position within the subgenus Mygalodelphys. The genetic distance between them was almost 6%, besides several morphological traits differentiating both species. However, some morphological traits previously proposed as diagnostic were found to vary with age, so an emended diagnosis for M. ronaldi is provided. Additionally, we include new information about the habitat, geographic range, and natural history of this elusive species.

Original languageEnglish
Pages (from-to)189-204
Number of pages16
JournalMammalian Biology
Issue number1
StatePublished - Feb 2022

Bibliographical note

Funding Information:
We thank World Wildlife Fund Peru (WWF Perú) for the Travel Grants for the fieldwork (TD 10–TD 16, TD 96–TD 99, TE 01, and TE 02). Also, we thank Maribel Taco, Rocío Bardales, Carlos Ruelas, Nadia Espinoza, Mercedes Molina, Lisset Gómez, Pedro Huanca, Christian Loaiza, and personal of MABOSINFRON for their helping in the fieldwork; Omar Ruelas for performing the ratio diagram; José Luis Mena for the support to this study; Rob Voss for providing measurements of M. handleyi and a critical review of an earlier draft of this manuscript. Besides, we thank the editor and three anonymous reviewers for their critical suggestions to improve this work. Finally, we thank the Ministerio de Agricultura y Riego (MINAGRI) for giving us the research permit with Resolución de Dirección General N° 0125-2015-SERFOR-DGGSPFFS. This work was done under the objectives of the DIMAPA research group of the Vicerrectorado de Investigación y Posgrado of the UNMSM.

Publisher Copyright:
© 2022, The Author(s) under exclusive licence to Deutsche Gesellschaft für Säugetierkunde.


  • Distribution
  • Habitat
  • Molecular analyses
  • Morphology
  • Mygalodelphys


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