Melanosclerites from the Late Ordovician strata of the Shiala Formation, Indian Gondwana

•Fossil melanosclerites recorded from the Shiala Formation of Indian Gondwana.•Study area is part of low palaeolatitude, lies below Ordovician–Silurian boundary.•Fossils are comparable with Öjlemyr Cherts of Sweden, a high palaeolatitudinal site.•Literature on melanosclerites are rare globally, the findings robust the record.

Melanosclerites, organic-walled microfossils of problematic affinity, are recorded herein from the lower to middle part of the Shiala Formation of Late Ordovician age and is situated below Ordovician–Silurian boundary established previously by acritarchs data. The assemblages recovered yielded the melanosclerites taxa Melanoporella clava, Melanoporella bulla?, Melanoporella polonica, Melanoporella sp. 1, Melanoporella sp. 2 and Melanosteus sp. The Ordovician–Silurian sedimentary sequence discussed herein was a part of the Gondwanan palaeocontinent situated at ∼25 to 30°S. The melanosclerite assemblage recovered herein from the Shiala Formation is broadly comparable with the Öjlemyr Cherts of Sweden, situated at high palaeolatitude and also of Late Ordovician age. Melanosclerites have not previously been studied in detail from Indian Gondwana and published records on this fossil group are rare in general. The present findings improve our knowledge on this group.