Über Vorkommen und Bedeutung von Terpsinoe americana (Bail.) Ralfs in den Ablagerungen des Litorinameeres

• Published in: Bulletin of the Geological Society of Finland Vol. 56; no. 1-2; pp. 117 - 133
• Main Authors: Alhonen, P., Heino, A., Tynni, R.
• Format: Journal Article
• Language: English
• Published: Geological Society of Finland 01.12.1984
• Subjects: diatoms; Litorina Sea; Terpsinoe americana
• ISSN: 0367-5211; 1799-4632
• DOI: 10.17741/bgsf/56.1-2.008

The subject of this paper is the occurrence and significance of the subfossil diatom Terpsinoe americana (Bail.) Ralfs. New observations of this species have recently been made in Finland. Although Terpsinoe americana is rare in the developmental history of the Baltic Sea, it occurs in many cores in the benthonicepiphytic community and among the planktonic diatoms. As a typical oceanic species, Terpsinoe americana is related to the maximum salinity level and temperature of the Litorina Sea, although it probably lived in the ecological periphery of the sea. The disappearance of this species coincides with the decrease in salinity of the Baltic Sea and the end of the Holocene Climatic Optimum. Taxonomical problems and the recent ecology of Terpsinoe americana are also discussed. The valvar structure of the species in the Finnish material presented in this paper was examined by SEM and found to be consistent with that of the diatoms of the family Biddulphiaceae.