Language: English
The state of Nagaland, situated in the northeastern part of India covers an area of about 16,579 sq. km. in the northern extension of the Arakan Yoma which represent orogenic upheavals in this part of the country during the Cretaceous and Tertiary periods. This region was a part of the Tethys Sea in Archaean period. Repeated orogenic movements accompanied by extensive igneous intrusions occurred in the successive periods that influenced the geologic and tectonic alignments of the region. The rock sequence is of geosynclinal facies represented by strata of Cretaceous to Tertiary age. Several fossil bearing localities have been recorded in recent past, especially in the Disang Group of sediments. The exploration and updating of records of animal fossils were conducted as a part of the programme of preparation of exhaustive faunal account of the state of Nagaland by the Zoological Survey of India
Altogether 134 species of animal fossils have been recorded, viz., 19 species of Protozoa: Foraminifera, 41 species of Protozoa: Radiolaria, 25 species of Mollusca: Gastropoda and 49 species of Mollusca: Bivalvia (Pelecypoda). Of these, 19 species of Gastropoda and 33 species of Bivalvia (Pelecypoda) are recorded first time from the rock beds of Nagaland state. The assemblage of the fauna ranged from Late Cretaceous to Upper Eocene in age.