Aragonictis araid, gen. et sp. nov., a small-sized hypercarnivore (Carnivora, Mustelidae) from the upper middle Miocene of the Iberian Peninsula (Spain)

ABSTRACT

Small to medium-sized mustelids from the last 18 million years represent a heterogeneous group of carnivorans with a wide-ranging record in the northern hemisphere. They were first referred to the genera Mustela and Martes, but lately ascribed to the latter, and hence considered as the longest-lived genus within Mustelidae. However, a great many of these forms have been based upon fragmentary material and Martes has conformed progressively to a wastebasket nomen for species of uncertain relationships. Here, we describe dentognathic material of a small-sized mustelid from three middle Miocene (MN7 + 8, latest Aragonian) localities of the Iberian Peninsula that constitutes a new genus and species. Aragonictis araid, gen. et sp. nov. represents a distinct taxon if compared with early/middle Miocene forms ascribed to “Martes” spp., especially the similar-sized early Miocene Circamustela? laevidens and the middle Miocene “Martes” caedoti and “Martes” delphinensis. The finding of particular features in A. araid (low p2–3, loss or reduction of the p4 accessory cuspid with its main cuspid centrally located, presence of a sharp, beveled and lingually open m1 talonid, and reduction of M1 lingual platform) indicates affinities with the late Miocene Circamustela in the range of hypercarnivory. Our reassessment of “Martes” indicates possible evidence of cladogenesis for Miocene mustelidae with, at least, two different events being recognized in Europe—the latter during MN7 + 8 to MN9 with presence of Aragonictis and Circamustela. The finding of A. araid further confirms the presence of more densely forested environments than expected in inner Iberia during the latest middle Miocene.

ACKNOWLEDGMENTS

We thank the following colleagues for kindly providing us with comparative material and photographs of fossil mustelids: P. Mein and E. Robert (UCBL, France), C. Argot (MNHN), G. Rössner and M. Schellenberger (BSPG, Germany), M. Morlo, O. Kullmer and C. Hemm (SMF, Germany), M. Rummel (Naturmuseum Augsburg, Germany), S. Fraile and A. Garvía (MNCN, Spain), J. M. Robles and D. M. Alba (ICP, Spain), I. Canudo (MCNUZ, Spain), L. Costeur (NMB, Switzerland), J. O. R. Ebbestad and V. Berg-Madsen (PMU, Sweden), and the staff of Servicio de Técnicas No Destructivas: Microscopía Electrónica y Confocal y Espectroscopía del MNCN-CSIC. We also thank C. Langa for finding the fossils from Andurriales, and E. Cantero (MNCN) for the preparation of the material. We are indebted to the editor T. Martin and the reviewers L. Werdelin and M. Morlo for their useful comments and suggestions, which made meaningful improvements to the original manuscript. This study was supported by the Government of Aragon (Group ref. E33_20R), the Research Group UCM 910607, the Spanish Ministry of Economy and Competitiveness and FEDER funds (Research Projects PGC2018-094122-B-100 and PID2020-116220GB-100), and the Spanish Ministry of Science, Innovation, and Universities (“Juan de la Cierva Formación”, ref. FJC2018-036669-I).