Cenomanian–Coniacian Upper Cretaceous foraminiferal fauna of Lithuania

• Published in: Geologija
• Main Author: Venckutė-Aleksienė, Agnė
• Format: Article in Journal/Newspaper
• Language: Lithuanian; English
• Published: 2010
• Subjects: Foraminifera; Planktonic; Benthic; Upper Cretaceous; Biostratigraphy; Palaeogeography; Planktonic foraminifera
• Online Access: http://lmavb.lvb.lt/LMAVB:ELABAPDB5911242&prefLang=en_US

Foraminiferal assemblages form a unique fauna succession from the Cenomanian to Maastrichtian stages in Lithuania; the Cenomanian-Coniacian succession is discussed in this paper. The first Cretaceous planktonic foraminifera species appeared in the Early Cenomanian. The Cenomanian planktonic foraminiferal association consists of the relatively abundant genus Hedbergella. However, Cenomanian planktonic foraminifera are rare compared to benthic; the latter are numerous, and their assemblage contains various calcareous and agglutinated species. As a result of environmental changes, foraminiferal assemblages gradually changed as well. The newly formed deep-water niches in the Turonian allowed spreading the keeled forms of planktonic foraminifera. Taxonomically, Turonian-Coniacian foraminiferal assemblages are mainly composed of species of the following genera: Praeglobotruncana, Helvetoglobotruncana, Dicarinella, Marginotruncana.