Desmanodon sp.

Ziegler, Reinhard, 2003, Moles (Talpidae) from the late Middle Miocene of South Germany, Acta Palaeontologica Polonica 48 (4), pp. 617-648 : 643-644

Desmanodon sp.

Fig. 14 .

Material and measurements.—Petersbuch 10, P10−618.1–6: NHMA P10−618/1, left dentary fragment with p4–m1; p4 (1.34×0.78), m1 (1.83×1.26×1.37); CRW P10.618/2, left m1 (1.81×1.16×1.31); NHMA P10−618/3, right dentary fragment with p2–p3; p2 (0.95×0.52), p3 (1.07×0.63); NHMA P10−618/4, right maxilla fragment with P4, P4 (1.99×1.88); CRW P10.618/5, right M1 (ca. 3.25×2.62); CRW P10.618/6, left M3 (1.28×2.50); NHMA P10−619/1, left humerus fragment, DS (2.67); NHMA P10−619/2, right humerus fragment, DS (2.39).

Description

Dentary.—There are only two short fragments of the horizontal ramus, one showing several pitting marks, which at the first glance look like foramina. On the other fragment p2 and p3 overlap each other.

Lower dentition.—The lower teeth are slightly amblyodont, i.e., they have inflated cusps. The premolars are double−rooted and increase in size from p2 to p4. The cusp is situated above the anterior root. In the p2 the cingulid is confined to the posterior half. The p3 has a postero−lingual crest and a weak anterior and posterior cingulid, respectively. The p4 is more heeled. In the m1 the talonid is longer and wider than the trigonid. The small trigonid−angle is conspicuous The oblique cristid runs quite buccally and extends to the posterior base of the protoconid. The paracristid is rounded. It forms an acute angle with the protocristid. There is only a weak precingulid, an ectocingulid confined to the hypoflexid and a somewhat more marked postcingulid.

Maxilla.—The maxillary fragment shows the lacrimal foramen above the posterior root of M1 and the alveoles of a triple−rooted P3.

Upper dentition.—The P4 is surrounded by a continuous cingulum. It has neither parastyle nor protocone, but an extended lingual heel. The postparacrista, which connects paracone and metastyle, is buccally concave. In the M1 the mesostyle is deeply divided and the protocone situated rather anteriorly. The parastyle is broken off. Preprotocrista and precingulum are separated by a notch, whereas postprotocrista and metacingulum are continuous. Para− and metaconule are hardly visible. The M3 is heavily worn. The only morphological detail, which survived wear, is the continuous paracingulum.

Humerus.—Both specimens are superficially corroded and preserved without their proximal parts. The most conspicuous character is the extremely long ledge−like teres tubercle. The broad shaft gives the humerus a compact appearance. The pectoral ridge and a lateral ledge include an acute−angled triangle. The pectoral tubercle extends further distally than the teres tubercle. The supratrochlear fossa is small. Between the trochlea and the fossa for the m. flexor digitorum profundus ligament there is a wide arc. The olecranon fossa is wide but not deep.

Discussion

The above listed specimens are pooled together because of their compatible overall size and because all teeth share the amblyodonty. The humeri are not referable to any other dentition. In the divided mesostyle and the anterior position of the protocone of M1, the short descending oblique cristid of m1 and in the inflated cusps of all teeth as well in the long teres tubercle of the humerus the sample fits well with Desmanodon , a genus well−represented in the Lower and Middle Miocene of Anatolia ( Engesser 1980; van den Hoek Ostende 1997), the Lower Miocene of Greece ( Doukas 1986), South Germany ( Ziegler 1985; Ziegler and Fahlbusch 1986) and Spain (van den Hoek Ostende 1997). However, another diagnostic feature of Desmanodon , the marked metaconule of the upper molars, is missing. Therefore, the Petersbuch 10 sample is not referable to any known species of the Desmanodon . In D.daamsi van den Hoek Ostende, 1997 the metaconule is also poorly developed and even may be absent. However, in this species the trigonid is distinctly longer and the mesostyle of M1 is more spaced. As the majority of defining characters is present in the material under study, it can be assumed that the specimens represent a species of Desmanodon . Because of lack of sufficient material I refrain from describing a new species. The Petersbuch 10 sample represents the latest record of the genus in Germany.

Figures

Fig. 14. Desmanodon sp., Petersbuch 10. A. Right dentary fragment with p2–p3, NHMA P10−618/3, occlusal view; ca. × 15. B. Left dentary fragment with p4–m1, NHMA P10−618/1, occlusal view; ca. × 15. C. Right P4, NHMA P10−618/4, occlusal view; ca. × 15. D. Left humerus, NHMA P10−619/1, anterior view; ca. × 7.5. E. Right humerus, NHMA P10−619/2, posterior view; ca. × 7.5.