The first record of calcitarchs from the Takche Formation (Ordovician–Silurian), Himalaya (India)

Limestones of the Takche Formation (Spiti, Himalaya) are characterized by normal marine fauna and flora typical for the Late Ordovician. The flora is represented by algae, mostly by receptaculitids and dasyclad green algae. Various calcareous microorganisms such as calcitarchs, Rothpletzella and Girvanella are present. There are some differences in the microfossil content and abundance between different lithofacies of the Takche Formation. Two main biofacies types could be recognized on the basis of the abundance of algae and calcitarchs, namely algal rich and algal poor biofacies. The abundance of dasyclad green algae in limestones of the Takche Formation is characteristic of the warm climate. The Himalaya (Gondwana) has calcitarchs in common with Baltica.