Biju became increasingly fascinated with frogs that he encountered during the several field expeditions he conducted in the Western Ghats in search for plants. To be able to fully explore the world of amphibians Biju eventually quit his research in plant science in 2000 and joined with Franky Bossuyt at the Amphibian Evolution Lab, Vrije Universiteit Brussel and obtained his second PhD, this time in Amphibian Systematics. In less than a decade of his professional career as amphibian systematist, Biju's efforts have already thrown up over 100 new species and formally described 96 new species, eight new genera and two new families of amphibians. Remarkable among his discoveries are the entirely new and famed purple frog family Nasikabatrachidae from the Western Ghats of India, published in the journal Nature This discovery was heralded as once-in-a-century find because the last time a new family of amphibians was described was almost 100 years back. His second discovery of a new amphibian family was in 2012, the Chikilidae, popularly called tailless burrowing caecilians or chikilids, published in the journal Proceedings of the Royal Society, Series B. This discovery was called the 'discovery of the year' and as 'another giant scientific discovery'. Both these discoveries of ancient lineages (both the families about 140 million years old) shed significant light on biogeographic history of the Earth, particularly that of the Gondwana, and in understanding the present-day continental distribution patterns of organisms-while the closest relatives of the purple frog lives 3,000 km across the Indian Ocean in the Seychelles, that of the chikilids is found 7,000 km in Africa. Notable among his new species discoveries are India's first canopy frog Raorchestes nerostgona; India's smallest tetrapod Nyctibatrachus minimus, a frog whose adults do not grow more than 10 mm; and Nasikabatrachus sahyadrensis, the famed purple frog.