Kaszab Zoltán (szerk.): A Magyar Természettudományi Múzeum évkönyve 64. (Budapest 1972)

Jánossy, D.: Middle Pliocene microvertebrate fauna from the Osztramos Loc. 1. (Northern Hungary)

To obtain precisely the dimensions of this form I measured 50 M

A specimens of the Glis of Osztramos 1. The length of these teeth ranges between 1.5—1.8 mm. As follows from the scatter diagram made from these measurement data (see fig. 1), this dormouse is statistically quite different from the Pleistocene and recent members of this array of species. The same measurements are given by KOWALSKI (1963) as 1.5-1.8 mm for Podlesice (n=9) as 1.3-1.7 mm for Wçze (n=23), and as 1.5-1.7 mm for Rebielice (n=7). The width of the same tooth is 1.3-1.7 mm at Osztramos (n=50), 1.41.7 mm at Podlesice (n=5), 1.5-1.7 mm at Wçze (n= 12) 1.5-1.7 mm at Rebielice (n=7). These measurements indicate an increase in size during the Late Pliocene; the stratigraphically older remains appear in the average smaller in size than the younger ones, and the Osztramos-species seems to belong to the former one. Muscardinus pliocaenicus KOWALSKI, 1963 — Muscardinus sp. A mandible with complete tooth row as well as a dozen isolated teeth prove the presence of a dormouse in the Osztramos 1 fauna. All the remains belong to a form slightly smaller than the recent one, described by KOWALSKI (1963). The dimensions, however, indicate in my opinion the presence of tw

r

o different forms. A more abundant material may later corroborate the following observations : the length and with (at the hind end) of M, in one type are 1.2 x 1.1; 1.4 x 1.2; 1.5 x 1.1. A slender form of M

x shows the following dimensions (length x width) : 1.3 x 0.9 ; 1.2 x 0.9. KOWALSKI (1963) mentioned this extreme variation in Muscardinus pliocaenicus from Podlesice too. Grlirulus (Amphidyromys) pusillus HELLER, 1936 An M

2 and M

3 from loc. 1/c and two M.

1 or M

2 from loc. 1/b may be assigned to a very small form of a dormouse. The uniform, longitudinal enamel ridge along the inner side of the teeth, the labially strongly forward-curved transversal ridges, and the subsquare form of the intermediate molars speak unambiguously for the form described by HELLER (1936) and DEHM (1962) from the Lowest Pleistocene of Germany, as well as by KOWASLKI (1963) from the Middle Pliocene of Podlesice (see Plate III. Fig. 6.). The relation of Amphidyromys pusillus HELLER, 1936, to the morphologically very near recent Eastern Asiatic Glirulus japonicus SCHTNZ is problematic. The length X width measurements of the Osztramos-from are: M

2

: 1.05x1.05; M

3

; I. 05x0.92, that is, of nearly the same size as in the formerly described remains of this form. The relation to the seemingly slightly smaller form, A. gemmula KRETZOI 1962, is problematic. Zapodidae Sminthozapus janossyi SULIMSKI, 1962 A right M

2 from loc. 1/c belongs unambiguously to the jumping mouse described by SULIMSKI (1962). The tooth agrees in size, structure and brachyodonty in all details with SULIMSKI'S very correct figure (1962, Table II. fig. 2. ; see Plate II. fig. 6 in this paper). There is a strongly built anteroloph, with a little crest on 3 Természettudományi Múzeum Évkönyve 1972.