............................................................................................................................................ 5 INTRODUCTION ................................................................................................................................... 6 Conservation begins by species discovery ................................................................................... 6 Trends in species discovery: Amphibia ......................................................................................... 7 Species and systematics under molecular evolutionary framework ....................................... 9 Historical perspective to amphibian systematics in South Asia ............................................. 10 Amphibian diversity and conservation challenges in Bangladesh ........................................ 11 Aims .................................................................................................................................................. 13 MATERIALS AND METHODS ............................................................................................................ 14 Taxa and specimens ...................................................................................................................... 14 Morphological measurements ..................................................................................................... 15 Sequence analyses and phylogenetic methods.......................................................................... 16 Divergence time estimation ......................................................................................................... 17 Bioacoustic analyses ..................................................................................................................... 17 Ethics Statement ............................................................................................................................ 17 RESULTS AND DISCUSSION .............................................................................................................. 18 Phylogenetic relationships of Fejervarya and Zakerana genera ........................................... 18 New Species ..................................................................................................................................... 20 Zakerana and Fejervarya ......................................................................................................... 20 Euphlyctis .................................................................................................................................... 21 Microhyla .................................................................................................................................... 22 Potential threats ............................................................................................................................ 23 CONCLUSIONS AND FUTURE DIRECTIONS .................................................................................... 25 ACKNOWLEDGEMENTS .................................................................................................................... 26 REFERENCES ....................................................................................................................................... 27 The thesis is based on the following articles, which are referred to in the text by their