First Ordovician chitinozoans from Indian Gondwana — New evidence from the Shiala Formation

Abstract

The Shiala Formation of the Garhwal-Kumaon subbasin of the Tethyan Himalaya, has been sampled for chitinozoans in the Chamoli district of Uttarakhand, India. The greenish gray colored silty shale at the lower horizon of Shiala Formation yielded a relatively rich though poorly diverse assemblage of chitinozoans. The chitinozoans are mostly acceptably well-preserved. The assemblage is dominated by two species, i.e. Belonechitina capitata and Belonechitina micracantha with rare specimens of Conochitina chydaea. These microfossils are very poorly documented from the low-latitudinal part of Gondwana and this is the first time that they are reported from this part of globe. The chitinozoan data are from below the Ordovician–Silurian boundary as indicated by an acritarch study from the same section, which is in agreement with our identification of the species that suggest a Mid to Late Ordovician age.