Ingerana occidens

The western trickle frog, Ingerana occidens, was identified by R. S. Naveen of Griffith University in the Garo and Khasi Hills of Meghalaya, in surveys from 2024 to 2025. The name is Latin for 'west': it is the westernmost known species of its genus. Compared with the northern I. borealis, found across the Brahmaputra River, it differs by about 18% in its genetic code, is noticeably smaller (adult females reach about 26 mm) and has a clearly visible, protruding eardrum, where the northern species has an almost invisible one. (Research Matters and other news reports).

Records of I. borealis from south of the Brahmaputra are presumed to belong to this species. Its closest relative is the recently named Mizoram species Ingerana aizawl, at 4.8 to 6.6% genetic distance. (news reports).