Dinoflagellate cysts from the Bathonian – Tithonian (Jurassic) of North Bulgaria. I. Taxonomy of Bathonian and Callovian dinoflagellate cysts

Pages: 
pp. 3-45
Geological Institute, Bulgarian Academy od Sciences, 1113 Sofia, Bulgaria
Abstract: 

The Bathonian and Callovian sediments of North Bulgaria yielded rich and commoly wellpreserved dinocyst assemblages. The assemblages studied are derived from 70 boreholes and 2 outcrops. In the present paper the taxonomy of the Bathonian and Callovian dinocysts established is considered. According to the archeopyle type they are divided into 4 groups: dinocysts with apical archeopyle, dinocysts with intercalary archeopyle, dinocysts with precingular archeopyle and dinocysts with combination archeopyle. 86 species belonging to 42 genera, a lot of them being of considerable biostratigraphic importance, are described. The geographic distribution and stratigrapic range in Bulgaria of these species are presented. The genera identified are: Adnatosphaeridium, Atopodinium. Belodinium, Chlamydophorella, Cleistosphaeridium, Compositosphaeridium, Dingodinium, Ellipsoidictyum, Escharisphaeridia, Kylindrocysta, Lagenadinium, Lithodinia, Parvulodinium, Rigaudella, Sentusidinium, Stephanelytron, Valensiella, Carpathodinium, Glomodinium, Kalyptea, Pareodinia, Tabulodinium gen. n., Aldorfia, Chytroeisphaeridia, Diacanthum, Gonylodinium, Gonyaulacysta, Heslertonia, Rhynchodiniopsis, Scriniodinium, Tubotuberella, Ctenidodinium, Dodekovia, Eodinia, Korystocysta, Mendicodinium, Mosaicodinium gen. n., Nannoceratopsis, Polygonifera. Sirmiodiniopsis, Sirmiodinium, Wanaea. Predominating in the composition of the dinocyst assemblages are the species of the genera Ctenidodinium Lithodinia, Gonyaulacysta and Pareodinia. The following new species are described: Tabulodinium senarium sp. n. and Polygonifera? aspera sp. n., a new combination – Mosaicodinium mosaicum comb. n., and Lithodinia. sp. A and Lithodinia sp. B. In order some characteristic morphological feature in the species of the genus Tubotuberella to be determined, a new term – inclination has been introduction.

VOLUME 20 (2)/April 1990

Geological lnstitute, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria
|
Rljksuniversiteit Utrecht, Laboraroritum voor Paleobotanie en Palynologie, Heidelberglaan 2, Utrecht 2506, Nederland

Geophysical Institute, Bulgarian Acadrmy of Sciences, 1113 Sofia
|
Geophysical Institute, Bulgarian Acadrmy of Sciences, 1113 Sofia