The last Iberian gomphothere (Mammalia, Proboscidea): Anancus arvernensis mencalensis nov. ssp. from the earliest Pleistocene of the Guadix basin (Granada, Spain)

Abstract

This work describes a new finding of Anancus arvernensis a maxilla fragment that preserves M2 and M3 from the earliest Pleistocene (c.a. 2.5-2.4 Ma) at the Fon-elas SCC-3 site (Cuenca de Guadix, Granada, Spain). This fossil is attributed to a new chronosubspecies based on the combination of anatomical features shown by M3: a primitive anatomical pattern plus derived features. The primitive features include the hexalophodont condition, a massive, rectangular distal outline, inconspicuous enamel folding, and indiscernible anancoidy. The derived features tooth-valleys covered by cement and the small overall size of the tooth are typical of the last representatives of the lineage. This mosaic of features allows a new chronosubspecies to be proposed: Anancus arvernensis mencalensis nov. ssp. This would be the youngest representative of the genus Anancus known for the Iberian Peninsula (MNQ 17a), and represents an intermediate evolutionary stage between Anancus arvernensis arvernensis and Anan-cus arvernensis chilhiacensis, the last known representative of the European lineage. A. arvernensis mencalensis therefore forms part of a temporal cline in the configuration of M3 over the Plio-Pleistocene transition. These anatomical changes could have occurred as a response to the aridification that began around 2.5 Ma, which led to changes in the composition of plant communities. © Society for Vertebrate Paleontology January 2014.