Dr. Nagy I. Zoltán szerk.: Fragmenta Mineralogica Et Palaentologica 5. 1974. (Budapest, 1974)

Diagnosis: The up to the present known largest member of the genus. Description and remarks: Only the anterior part of the first upper molar preserved, the crown of the posterior part somewhat detached (ridges lacking). There are on the oral part three well developed ridges present. Chief features the same as in Muscardinus avellanarius: occlusal surface subquadrate, the ridges slightly arched posteriorly, but the anterior part more rectangular and the ridges more prominent (stronger built) than at the recent species. Anteroloph well developed and not connected to .either protocone or paracone. Proto- and metaloph form a rectangular, U-shaped pattern. Extra ridges not present. There are five roots present, in the same arrangement as at the recent form. Length of the occlusal surface cca. 2.70 mm, largest width 1.70 mm. So far the following fossil species of the genus are described (including the subgenera Eomuscardinus HARTENBERGER 1966 and Muscardinulus THALER 1966): Muscardinus (Eomuscardinus) sansaniensis (LARTET, 1851) M. dacicus KORMOS, 1930 M. pliocaenicus KOWALSKI, 1963 M. davidi HUGUENEY and MEIN, 1965 M. vireti HUGUENEY and MEIN, 1965 M. thaïe ri DE BRUIJN, 1966 M. (Eomuscardinus) vallesiensis HARTENBERGER, 1966 M. crusafonti HARTENBERGER, 1966 M. (Muscardinulus) bouzigensis THALER, 1966 This species as well as M. gracilis DEHM 1950 and M. modestus DEHM, 1950 (incl. in the subgenus Glirudinus DE BRUIJN, 1966) represent different morphotypes and different evolutionary lines, but the length of the M* of none of these species exceed 1, 8 mm, the width 1, 5 mm. Such (viz. larger) dimensions as our fossil specimen shows among recent and fossil dormice only Leithia melitensis (ADAMS, 1863) although with a quite different molarstructure. The pattern of the occlusal surface of the molar agrees morphologically mostly with that of the same totth of Muscardinus especially M. avellanarius or crusafonti, other genera we cannot take into consideration. However, there are observable some differences which perhaps exceed the boundary of generic limits. The discovery of further material may decise in this question. Arvicolidae GRAY 1821 Promimomys KRETZOI 1955 Promlmomys microdon n. sp. Derivatio nominds: "microdon", referring to the small size of the tooth of the type specimen . Stratum locusque typicus and age: see at the description of Muscardinus giganteus. Holotype: right fragmentary first upper molar. Inv. No. V. 74. 3. Collection of the Paleontological Department of the Museum of Natural History, Budapest.