Brachiopoda

Helmersenia Pander, 1860

Selection of related publications
Nemliher, J., Kurvits, T., Kallaste, T. & Puura, I. 2004. Apatite varieties in the shell of the Cambrian lingulate brachiopod Obolus apollinis Eichwald. Proceedings of the Estonian Academy of Sciences. Geology 53, 4, 246-256.
Puura, I. 1996. Lingulate brachiopods and biostratigraphy of the Cambrian-Ordovician boundary beds in Baltoscandia. Doctoral Thesis, pp. 1-214.
Popov, L. E., Khazanovitch, K. K., Borovko, N. G., Sergejeva, S.P.; Sobolevskaya, r.F. 1989. The key sections and stratigraphy of the Cambrian-Ordovician phosphate-bearing Obolus beds on the north-east Russian Platform.
Kaljo, D., Borovko, N., Heinsalu, H. Khazanovich, K., Mens, K., Popov, L., Sergejeva, S., & Sobolevskaja, R. 1986. The Cambrian-Ordovician boundary in the Baltic-Ladoga clint area (North Estonia and Leningrad Region, USSR). Proceedings of the Academy of Sciences of the Estonian SSR. Geology 35, 3, 97-108.
Gorjansky, V. J. 1969. Inarticulate brachiopods of the Cambrian and Ordovician of the northwest Russian Platform.
References based on distribution