TMGB vol 7 (1998)

In Ambérieu 2C two species seem to be present. One of these will be described hereafter as a new species (N. ambarrensis); the other one is classified as N. cf. skofleki (see Fig. 10), and is represented by a relatively big M 1 (21.0 x 12.5), that has its anterolophid subdivided into 3 cusps; the separation between the lingual cusp and the central one is quite deep; there are 3 anterolophulids, a mesolophid that reaches the molar border, and an ectomesolophid, descending from the foremost tip of the hypoconid; the entoconid is connected to the posterolophid by a longitudinal crest that divides the posterosinusid into two valleys.

It comes together with an M2 (15.5 x 13.3) that is slightly longer, and considerably broader than the rest of the specimens, and an M 3 (16.4 x 12.4), that is both longer and broader. In the M 2 the lingual anterolophid is a thin line on the anterior border of the tooth, the mesolophid reaches the lingual border. In the M 3 the anterosinusid is very small, but there is a clear lingual anterolophid; the mesolophid is of medium length, and there is a strong ectostylid. There is a backward spur on the anterior arm of the hypoconid, and a forward spur on the posterior arm, that form an interrupted longitudinal crest, comparable to the crest observed in M 1 . The M 1 is unworn and the M3 is medium-worn, so they belong to different individuals, which makes it probable, that this crest is significant for the species, and not just an accidental occurrence.

Tripartite anteroconids have been observed in Cricetulodon sabadellensis from Can Liobateres, in Rotundomys from Montredon, and in Neocricetodon populations from Eichkogel, Crevillente 23, and Lissieu.

C. sabadellensis from Can Llobateres and R. montisrotundi from Montredon frequently have a tripartite anteroconid, but they never have a long mesolophid; in A. aff. plinii from CR23 the mesolophid is never long too, and the specimen from Lissieu has no mesolophid. In N. skofleki from Eichkogel the anteroconid may consist of three cusps, the mesolophid is long, and there may be a longitudinal crest in the posterosinusid. Our specimens are at the upper size limit of the Eichkogel population. Ambérieu 2C is placed in MN1O and Eichkogel is placed in MN1 1. The type-locality of N. skojieki is Tardosbánya (MN 12, Mein, 1990). Such a long vertical range is not usual within this genus. Csákvár, the type-locality of N. schaubi is placed in MN 10, so one should consider the possibility that we are dealing with that species, but the variability of N. schaubi is not known, and the only known M 1 has a bifid anteroconid.

So, by elimination, N. skojieki is the only known species that comes into account, but doubt remains because of the large size of the specimens, and because of the long stratigraphic range implied by this occurrence. Kohfidisch and Ambérieu 2C are of about the same age. This means N. cf. skofleki and N. fahlbuschi occur simultaneously. See for further remarks the chapter on phylogeny.

Material from Dionay: - The anteroconid is a simple ridge, or superficially subdivided. The anterolophulid is labial (1), or double (5), generally low or interrupted. The mesolophid reaches the molar border (11), or it is of medium length (1). In 8 out of 10 specimens there is an ectomesolophid that descends from the hypoconid.