The Middle Triassic Flora of the Tanga Basin, Tanzania

Abstract

The Bamba, Pangarawe and Kakindu outcrops of the Tanga Basin (Tanzania) yielded a diverse plant fossil assemblages, including Pagiophyllum, Voltziopsis, Heidiphyllum, and possibly Sphenobaiera. This composition of the plant fossil assemblage suggests a Middle Triassic age for the fossiliferous beds extending the fossil record in the Tanga Basin. The plant remains are preserved in fine-grained shales and silts, suggesting deposition in low-energy environments, such as lakes, with reduced transport from surrounding growing areas. The plants likely thrived in a dynamic ecosystem composed of coniferous forests interspersed with open vegetation, reflecting adaptation to varying environmental conditions driven by a seasonal, monsoonal climate. This study highlights the significance of the Tanga Basin in elucidating the floristic composition of Gondwana's mid-latitudes. The mid-latitudes of Gondwana, generally devoid of plant fossil findings, where previously assigned to the desert biome, whereas the finding support a seasonal climate of the temperate biome during the Triassic.