Mimomys hajnackensisfrom the Pliocene of the Netherlands

Abstract

We describe the occurrence in the Netherlands of three teeth of Mimomys hajnackensis (Arvicolidae, Rodentia) from three separate boreholes extending into marine deposits of the Maassluis Formation. These marine Pliocene/Early Pleistocene deposits at depth are overlain by, and interdigitate eastwards with, the freshwater deposits of the Waalre and Peize Formations (formerly known in part as the Tegelen Formation).Teeth identified as M. hajnackensis have not previously been described from the Netherlands although similar material has been reported from Pliocene deposits in Germany at Frechen and Hambach close to the Dutch border. The material described here comes from boreholes at the Polder de Biesbosch near Dordrecht, Diepenveen and Deventer. To our knowledge, these finds represent the oldest described rodent fossils from the Netherlands, corresponding to an absolute age of 2.9 to 3.3 Ma on the basis of comparison with other European localities, implying that the remains are reworked from older deposits.

U–Pb geochronology of zircons from fossiliferous sediments of the Hajnáčka I maar (Slovakia) – type locality of the MN 16a biostratigraphic subzone

“…2005; Mayhew et al . 2008). The name of M. hajnackensis was created by Fejfar (1961) for three teeth of the relatively large Mimomys species from Hajnáčka, which was clearly more primitive than M. polonicus Kowalski.…”

Small mammal assemblages from the Quaternary succession at Moriaanshoofd (Zeeland, the Netherlands) and their significance for correlating the Oosterschelde fauna

“…Local reworking of material from Early (and Middle) Pleistocene suggested by the coarse lag deposits above c. 37 m could explain recovery of a Trogontherium tibial fragment of large size, suggesting a Middle Pleistocene age, from the deep channel of the Oosterschelde, close to the Moriaanshoofd borehole position (Mayhew et al, 2008a). Another find from the Oosterschelde dredgings concerns an M2 from Arvicola terrestris with undifferentiated enamel (Dieleman, pers.…”

“…Given the low number of natural outcrops in the flat Dutch landscape, it is hardly surprising that the number of borehole sites with mammals (e.g. Mayhew, 2008; Mayhew et al, 2008a; Slupik et al, 2007; Van der Meulen & Zagwijn, 1974) exceeds the number of localities that were sampled by screen-washing (e.g. Van Kolfschoten, 1990a).…”

Fossil remains of shrews (Soricomorpha: Soricidae) and desmans (Talpidae: Desmaninae) from Norfolk, England, with biostratigraphic implications for the Plio-Pleistocene boundary in East Anglia

“…This collection is of particular importance because the small mammal assemblages have contextual information and a direct association with other biological proxies, allowing an assessment of the palaeoenvironment. As stressed by MAYHEW et al (2008), the presence of terrestrial mammals in the marine Crags suggests either they were washed into the marine environment or may have been reworked from pre-existing terrestrial deposits during transgressive-regressive cycles. It is currently not possible to gauge whether reworking is a significant factor in the taphonomy of the assemblages, and the following discussion is based on the assumption that the small mammal remains are broadly contemporaneous with the marine deposits in which they are found.…”