Miocene planktonic foraminifers occur in shale intercalated with thinly bedded siltstone and sandstone of the Surma Group in the foothills of the Naga Schuppen Belt of the Indo-Myanmar Range. Fourteen species from eleven genera are the first clearly imaged middle Miocene foraminifers recorded from the Surma Group in the Naga Hills. This new M5-M6 assemblage from the upper unit of the Bhuban Formation correlates to the uppermost Burdigalian to Langhian (16–14 Ma). Biostratigraphy, paleoenvironment and paleogeography of the assemblage are all significant. They provide a basis for widespread regional and global correlation constraining the timing of elimination of the final remnants of the Neotethyan seaway between India and eastern Eurasia. Results indicate that, unlike the western and Tibetan Himalayas where similar seaways disappeared before the Miocene, a shallow marine embayment that connected to the Indian Ocean endured in eastern parts of the India-Eurasia collision zone until the Middle Miocene.

中新世浮游有孔虫出现在印缅山脉 Naga Schuppen 带山麓的 Surma 群的夹层薄层粉砂岩和砂岩中。来自 11 个属的 14 个物种是第一个清晰成像的中新世中新世有孔虫，记录自纳迦山的 Surma 群。这个来自 Bhuban 组上部单元的新 M5-M6 组合与最上层的 Burdigalian 到 Langhian（16-14 Ma）有关。该组合的生物地层学、古环境和古地理意义重大。它们为广泛的区域和全球相关性提供了基础，这些相关性限制了消除印度和欧亚大陆东部之间的新特提斯海道最终残余物的时间。结果表明，