Vörös A. szerk.: Fragmenta Mineralogica Et Palaentologica 14. 1989. (Budapest, 1989)

Material: Bocskor-hegy Szilas- árok pedicle brachial 4'. 3 Dimensions (mm): 8. 4 /mm/ 12,5 10,0-• 7,8" fragmentary valve 15 12. 3 11. 8 10,0 It (see Fig. li Fig. 18 Scatter diagram of the relationship of width to length in Belothyris convexa Description: The biconvex shell is elongated, oval or rounded pentagonal in outline. The pedicle valve is much more convex than the brachial one. Maximum convexity of the pedicle valve coincides with the maximum thickness of the shell, at or somewhat anterior of the mid-line. Maximum width corresponds to the mid-line. The umbo is suberect with circular mesothyrid foramen and well-marked beak-ridges. The growth lines on the pedicle valve are conspicuous, increasing in density towards the anterior, forming rugae in adult individuals. The lateral sides of the valve are parallel to one another, forming an angular, box-like shell shape. The surface of the shell is pseudopunctate. Remarks: The external features of this form agree in detail with those of Belothyris convexa Smirnova. It differs from that only in being smaller in size, though this character is considered to be of ecological significance only. The internal structures are unknown. It differs from Belothyris pseudojurensis Leymerie in having a more elongated and narrow shape and more convex valves. Distribution: Barremian and Upper Aptian of the northern Caucasus. Belothyris cf. pseudojurensis (Leymerie, 1842) (Plate IV: 3- 10) 1847. Terebratula pseudo-jurensis Leym. - d'ORBIGNY (partim), p. 74, pi. 505, Figs. 12, 13, 16 (excl. Figs. 11, 14, 15) 1861. Terebratula pseudojurensis Leymerie - de LORIOL, p. 121, pi. 15, Figs. 19-21 1868. Terebratula pseudojurensis Leymerie - PICTET, p. 54, pi. 4, Figs. 13-14 ? 1898. Terebratula dzirulensis - ANTHULA, p. 70, pi. 3, Figs. 1-2 ? 1945. Dzirulina dzirulensis Anthula - NOUTSOUBIDSE, p. 232, pi. 4, Figs. 1-14 ? 1960. Belothyris reguláris - SMIRNOVA, p. 18, pi. 11, Fig. 2 ? 1970. Belothyris pseudojurensis Leymerie - OWEN, p. 70, pi. 9, Fig. 1-5, 7 ? 1972. Belothyris reguláris - SMIRNOVA, p. 102, pi. 9, Fig. 5 Material: 2 complete specimens, 12 pedicle valves, 14 fragments and 24 brachial valves from the Bocskor-hegy. Dimensions (mm): L 15 W 12 T 10 13 11 13 Description: The biconvex shell is rounded pentagonal in outline. The pedicle valve is more convex than the brachial one. Maximum width is at of posterior of the mid-line, maximum thickness is at the mid-line. The umbo is massive, curved. The beak-ridges are conspicuous. The foramen is mesothyrid to permesothyrid. Though the growth lines are very faint, they are well visible. The lateral side of the pedicle valve is separated from the ven-