Silurian and Devonian brachiopods from Severnaya Zemlya (Russian Arctic) Author Modzalevskaya, Tatiana L. All-Russia Geological Research Institute (VSEGEI), Srednij pr. 74, St. Petersburg, 199106 (Russia) modz @ IB 2567. spb. edu. text Geodiversitas 2003 25 1 73 107 journal article 10.5281/zenodo.5375016 1638-9395 5375016 Dubaria tenera Nikiforova & T. Modzalevskaya, 1968 ( Figs 22 J-M; 23) Dubaria tenera Nikiforova & T. Modzalevskaya, 1968: 68 , pl. III, figs 8-10. MATERIAL EXAMINED. — Three specimens from loc. 13, beds 64, 89, Matusevich River, October Revolution Island ( Männik et al . 2002 : figs 2, 5); Vodopad and Golomyannyj formations. REMARKS The specimens assigned to this species show some characteristics of external and internal structures identical to those of Dubaria tenera , illustrated by Nikiforova & Modzalevskaya from the Talikit Formation of East Siberia ( Fig. 23 ). Possibly, this species is a junior synonym of Atrypopsis varians Poulsen, 1943 described from the Offley Island Formation of Greenland ( Poulsen 1943: 44 , pl. 5, figs 13-16). These two taxa are morphologically very similar. However, the identification of our specimens is quite problematic due to the lack of the dorsal myophragm on them. This structure is one of the main diagnostic features of Atrypopsis and Dubaria Boucot, Johnson & Staton, 1964 ( Rubel 1970 ) . P. Copper (1991: 37) , restudying the atrypids, concluded that Atrypopsis , Dubaria , Rhynchatrypa Siehl, 1962 , and Barkolia Zhang, 1983 are junior synonyms of Septatrypa Kozlowski, 1929 . Hence, the occurrence of a short dorsal septum is an essential feature to identify Septatrypa ( Nikiforova et al . 1985: 44 , pl. 11, fig. 9). FIG. 24. — A , Eohowellella sp. , ventral view of a pedicle valve (N 64/12991), loc. 2, bed 79, Samojlovich Formation; B -F , Reticulariopsis talenti Lenz & Johnson, 1985 ; B , ventral view; C , dorsal view; D , lateral view; E , posterior view of a complete shell (N 65/12991); F , posterior view of a complete shell (N 66/12991), showing delthyrium, loc. 21581, Severnaya Zemlya or Pod’’emnaya formations. Scale bar: A, 5 mm; B-E, 2 mm; F, 2.5 mm. Order SPIRIFERIDA Waagen, 1883