A new hypercarnivorous mustelid (Mammalia, Carnivora, Mustelidae) from Batallones, late Miocene (MN10), Torrejón de Velasco, Madrid, Spain

Abstract

We describe dentognathic remains of four individuals of the poorly known mustelid Circamustela Petter, 1967 from the late Miocene sites of Batallones-3 and 5 (MN10, Torrejon de Velasco, Madrid, Spain). These new fossils allow us to describe Circamustela peignei n. sp., a more primitive species than Circamustela dechaseauxi Petter, 1967 from Can Llobateres (MN9, Vallès Penedès Basin, Spain). Circamustela peignei n. sp. shows, among other features, an M1 with a more developed metacone, a smaller metastylar area, a mesially located protocone, and a more developed m1 metaconid compared to that of C. dechaseauxi. The new taxon differs from most Euroasian Miocene marten-like mustelids, such as the middle Miocene martens "Martes"

The exceptionally high diversity of small carnivorans from the Late Miocene hominid locality of Hammerschmiede (Bavaria, Germany)

“…These forms are in need of a thorough taxonomical revision, which is beyond the scope of the present article. For practical issues we refer to all these Miocene forms as “ Martes ”, following [ 61 ], although [ 45 , 62 ] suggested that some Late Miocene forms can be classified as Martes . The species Mustela transitoria Gaillard, 1899 [ 63 ] has been considered as related to the aforementioned forms, but it has now been transferred to its own genus: Gaillardina Ginsburg, 1999 [ 38 ].…”

“…Other included species: Circamustela peignei Valenciano et al, 2020 [ 62 ]; Circamustela hartmanni sp. n.…”

“…Circamustela sp. Recently, [ 62 ] published a second species of the genus, Circamustela peignei , from the sites Batallones 3 and 5 (Late Miocene, MN 10, Spain) that differs from C . dechaseauxi mainly in the morphology of M1, but also in the more developed m1 metaconid and more conical m1 hypoconid.…”

“…Comparison: The plethora of marten-like mustelid taxa during the Middle and Late Miocene creates a relatively obscure taxonomic spectrum for the group. The genera Martes and Mustela have been used as wastebaskets for several fragmentarily known species, so the affinities of every taxon are not always clear (e.g., [ 45 , 62 ] ). However, the genus Circamustela can be easily distinguished from most of the other mustelids by considering its size and carnassial morphology: the small dimensions, the low P4 metastyle, the high m1 protoconid, the low m1 metaconid and the mesiodistally enlarged p4 are herein considered sufficient enough for the attribution of the present specimens to the hypercarnivorous genus Circamustela .…”

“…However, the genus Circamustela can be easily distinguished from most of the other mustelids by considering its size and carnassial morphology: the small dimensions, the low P4 metastyle, the high m1 protoconid, the low m1 metaconid and the mesiodistally enlarged p4 are herein considered sufficient enough for the attribution of the present specimens to the hypercarnivorous genus Circamustela . However, as noted in the past [ 45 , 62 , 81 ] the fossil record of the genus Martes is very problematic and a revision is needed in order to enable more secure attributions in the future.…”