Bjornkurtenia canterranensis ( Michaux, 1976 )

Popov, Vasil V., 2004, Pliocene small mammals (Mammalia, Lipotyphla, Chiroptera, Lagomorpha, Rodentia) from Muselievo (North Bulgaria), Geodiversitas 26 (3), pp. 403-491 : 470-472

Bjornkurtenia canterranensis ( Michaux, 1976) ( Fig. 37 A-C)

Trilophomys canterranensis Michaux, 1976: 166-168 .

“ Trilophomys ” canterranensis – Agadjanian & Kowalski

1978: 31.

Bjornkurtenia canteranensis – Kowalski 1992: 321- 327.

MATERIAL EXAMINED. — 1 m 1 (Ms52-1); (L × W) = 1.62 × 1.05.

DESCRIPTION

The tooth is two-rooted. The occlusal surface is simple, consisting of a posterior loop, three alternating triangles and an anterior cap, situated obliquely to the sagital axis. The dentine field of the anterior cap is widely connected with the triangle behind it. The enamel is thick and uneven. There are no dentine tracks.

REMARKS

The available molar is slightly shorter than the original material from Terrats (Roussillon, France), described as Trilophomys canterranensis . It differs from Trilophomys depereti Fejfar, 1961 , from Muselievo (see below) by having alternating triangles and by lacking dentine tracks. These features are characteristic for the genus Bjornkurtenia Kowalski, 1992 , comprising the materials from Terrats and Podlesice (MN14, Poland), previously referred to Trilophomys Depéret, 1892 . The species is also known from Gundesheim-4, MN15b ( Germany) ( Fejfar & Storch 1990). According to Kowalski (1992), Bjornkurtenia is one of the most primitive voles in the family Arvicolidae .

The available tooth is similar to the imperfect m1 from Osztramos 9, described as Promimomys microdon Janossy, 1974 , but it has a narrow dentine isthmus between the third triangle and the anterior cap. In this respect, it is very similar to Baranomys longidens ( Kowalski, 1960) . However, because the Hungarian specimen is damaged in its anterior part, for the time being, it is impossible to ascertain whether this difference has systematic value or not. Since the structure of the mandible is not known, the systematic position of the genus and species within the family Arvicolidae cannot be adjusted ( Kowalski 1992).

Family TRILOPHOMYIDAE Kretzoi, 1969

Figures

FIG. 37. — A-C, Bjornkurtenia canterranensis (Michaux, 1976); A, right m1, Ms52-1, lingual view; B, the same, occlusal view; C, the same, buccal view; D, E, Hystrix sp.; D, right P4, Ms396, occlusal view; E, the same, posterior view. Scale bars: 1 mm.