A new small mammal assemblage from the Pirro 12 “Terre Rosse” fissure filling (Gargano, Southeastern Italy).

The Pirro 12 fissure filling has been discovered and sampled by a team of the University of Torino during the 2005 field survey in the Dell’Erba Quarry (Apricena, Foggia). The occurrence of a very small Deinogalerix and of a very simple Mikrotia supported, at a first glance, the very old position of Pirro 12 in the biochronological succession of endemic faunal settlements of Gargano (Villier, 2011). In this communication the preliminary result of taxonomic studies of the small mammal assemblage of the Pirro 12 filling is presented. The Gliridae is by far the most common family in this site. Two species of the endemic genus Stertomys have been identified: the small-sized Stertomys cf simplex, and the larger-sized Stertomys cf lyrifer. The possible occurrence of Stertomy daamsi still needs to be ascertained. These Myomiminae closely resemble those of fissure Rinascita 1 reported in the literature. Murids are represented by two species of Mikrotia: one is very small, with very brachyodont crown and simple morphology of M/1, while the other is somewhat larger and hyspsodont, and has a slightly more complex occlusal pattern. Another Murinae species is rather common and although it is still being analyzed, it is the first new taxon reported from Pirro 12. A second one is a very large-sized and rather hypsodont cricetid (latu sensu) genus, which cannot be associated with any other cricetid so far reported from the Gargano Terre Rosse. Insectivores are represented by three mandibles without teeth of a small-sized Galericinae, as well as by a single remain of Crocidurinae. The sample is rather poor, and therefore the absence of characterizing taxa should be considered with caution. The occurrence of a new murine and of a new large cricetid distinguishes the Pirro 12 assemblages from all other fissure fillings. The shrew is present also in some old fissure fillings reported in the literature of the 1980’s (Martín-Suárez & Freudenthal, 2007). Stertomys lyrifer and S. symplex are found only in the fissure Rinascita 1, which is the second oldest fissure mentioned in the literature of the late 1970’s (De Giuli et al., 1987). The absence of Apodemus and Prolagus, two genera which are virtually present in all known fissure fillings from the Gargano, the absence of Hattomys, the endemic resident cricetidae, the absence of Apocricetus, Neocricetodon and Democriceton which are instead found in older fissures (i.e., Rinascita 1 and Biancone), together with the extreme primitiveness of Microtia, prove the ancient biochronological age of this fissure, changing the scenario of the oldest faunal settlements of the Abruzzo- Apulian paleo-bioprovince.