Paleobiological Significance of Trichome Inclusions in Baltic Amber from Goa, India

Abstract

Baltic amber (succinate) is a fossilized resin belonging to the Eocene period (44-49 million years old) derived from the Araucariaceae and Leguminosae families of trees containing up to 8 percent of succinic acid and compounds such as terpenoids and phenolic derivatives. Amber is primarily yellow in colour, having different shades ranging from light yellow to dark yellow to brown to black. This is the first report on the trichome bioinclusions from imported Baltic amber in Goa. Samples of imported Baltic amber were validated and studied for the presence of bioinclusions. Trichomes, also known as "stellate hairs," are present in the vast majority of angiosperms and are considered for some time to be of importance in comparative systematic studies. Trichomes have an important role as a defensive structure for plants. The trichomes are common in Baltic amber and have been considered as a characteristic of this type of amber. Higher flow of tourists from Russia to Goa by chartered flights has introduced many traded commodities like semi-precious stones and Baltic amber. Since amber of this quality was not easily available in India, the Baltic amber traded in Goa was utilized for scientific studies focused on the identification of biological inclusions after sorting and classifying the purchased samples from authentic traders. This paper reports preliminary analysis of fossilized trichome elements in locally purchased samples of Baltic amber imported from Russia. Specimens were subjected to stereomicroscopic and phase contrast microscopic analysis, and interesting inclusions entombed in amber were studied. Two types of trichomes were found to be present in the Baltic amber stellate hair type and glandular types. The stellate hair type of trichomes was minute and radially branched, ranging from 12 to 17 radii. Glandular trichomes were erect, with a unicellular glandular head and possessed a stalk which was both unicellular and multicellular.