Abstract (eng)
The insectivorous fauna from the Bavarian fissure filling Petersbuch 28 (Germany, Lower Miocene) is described. The dental, cranial and postcranial remains were described and measured according to the most common methods. The Metatheria are present with the herpetotheriid Amphiperatherium frequens erkertshofense (von Koenigswald, 1970). It is rather large for the subspecies. The lower molars are highly developed in the reduction of their posterior cingulid, but the upper molars lack the anticonus and are therefore less developed. The specimens represent a weakly developed form of A. frequens erkertshofense. The reduction of the posterior cingulid was a general trend within A. frequens (von Meyer, 1846), but was not a homogenous development. The Eulipotyphla are represented by members of the Erinaceidae, Dimylidae, Talpidae, Heterosoricidae and Soricidae. A large and rare Galericine was determined as cf. Lantanotherium Filhol, 1888. It has a slightly different morphology of the metaconulus of the M2 and weaker posterior cusps of the M3 than all known species of Lantanotherium, which was previously thought to have immigrated into Germany in the Middle Miocene. Galerix aurelianensis Ziegler, 1990 is rare; its M1 and M2 sometimes lack the posterior arm of the metaconulus, most probably due to a change in the abundance or quality of the consumed food. The relatively narrow p1 and p4 of the dimylid Chainodus intercedens (Müller, 1967) indicate the specimens from Petersbuch 28 to be weakly developed. The specimens of Plesiodimylus Gaillard, 1897 were determined as P. aff. chantrei Gaillard, 1897, following the opinion of other authors. The various specimens show affinities towards P. chantrei Gaillard, 1897, P. huerzeleri Müller, 1967 and P. bavaricus Schötz, 1985, respectively, without having enough differences to be divided into different species. The lower molars are more homogenous in morphology and size. The small m2 indicates P. aff. chantrei to be weakly developed. Plesiodimylus aff. chantrei is the most frequent species in Petersbuch 28. The most common talpid is Desmanella engesseri Ziegler, 1985. Its M1 is relatively short and has a weakly developed connection between the posthypocrista and the posterior cingulum. For the first time, a maxillary fragment a D4 was described. The humerus of D. engesseri was found for the first time. It differs from the humerus referred to Desmanella gudrunae Van den Hoek Ostende and Fejfar, 2006 and is similar to the humerus of Asthenoscapter meini Hutchison, 1974. The humeri of Myxomygale hutchisoni (Ziegler, 1985) are the most common humeri from Petersbuch 28. Proscapanus intercedens Ziegler, 1985 is represented chiefly by limb bones. Talpa sp. is determined by limb bones. Some talpid teeth could not be determined to species level. The Heterosoricidae are present with Heterosorex neumayrianus (Schlosser, 1887) only. The second most numerous species of the whole fauna is the soricid Soricella discrepans Doben-Florin, 1964. Its lower molars show bimodal length distributions, interpreted to show a small mixing of the fauna. Lartetium petersbuchense Ziegler, 1989 and Lartetium cf. prevostianum (Lartet, 1851) are rarer. Lartetium cf. prevostianum is older than the known findings of L. prevostianum. Florinia stehlini (Doben-Florin, 1964) is large compared to other sites. Miosorex desnoyersianus (Lartet, 1851) is also present. Miosorex pusilliformis (Doben-Florin, 1964) was found to be a junior synonym of M. desnoyersianus. The lower molars of Paenelimnoecus micromorphus (Doben-Florin, 1964) have a bimodal width distribution, indicating a small mixing of the fauna. The fauna described herein belongs to the end of the Mammal Zone MN 3 or the earliest MN 4. The bimodal width distribution of the lower molars of Paenelimnoecus micromorphus seem to indicate a sub-assemblage from MN 3 and another one from MN 4, but the possible hiatus is very short. Based on Amphiperatherium frequens and the Eulipotyphla, the assemblage from Petersbuch 28 is interpreted deposited next to the boundary between MN 3 and MN 4, so Petersbuch 28 is assigned to MN 3/4. The palaeoecological analysis, combining the principal component analysis, the correspondence analysis and the detrended correspondence analysis with knowledge about the palaeoecological preferences of the Eulipotyphlan families and Amphiperatherium frequens, indicates Petersbuch 28 to be fairly humid.