He specialised in fauna and human fossils of the
Indian subcontinent. From 1939 to 1963, he was the director of the
National Museum of Ceylon, and from 1961 to 1964, he was also the dean of the Faculty of Arts at the
Vidyodaya University. He described several
fossils and proposed
scientific names for
species and
subspecies, with several now identified as
dubious, including: • Sri Lankan
rhinoceros (
Rhinoceros sinhaleyus) in 1936 for a fossil found in
Ratnapura District • Sri Lankan
hippopotamus (
Hexaprotodon sinhaleyus) in 1937 •
Sri Lanka lion (
Leo leo sinhaleyus) in 1939 for two fossil teeth found at
Kuruwita •
Panthera tigris sudanensis was named in 1951 for a
tiger skin that he saw in a
Cairo bazaar. When he asked the shop owner for the origin of this specimen, he was told that the animal was shot in
Sudan.
Vratislav Mazák thought it likely that the skin was smuggled from
Iran or
Turkey to Egypt and commented "the situation is half-humorous, half-ironic". •
Javan elephant (
Elephas maximus sondaicus) was described in 1955 based on an illustration of a carving on the Buddhist monument of
Borobudur in
Java. It is considered
synonymous with the
Indian elephant (
E. m. indicus). •
Balangoda Man (
Homo sapiens balangodensis) in 1955 • Sri Lankan rhinoceros (
Rhinoceros kagavena) in 1956 • Sri Lankan
gaur (
Bibos sinhaleyus) in 1962 He served as president of the
Ceylon Branch of the Royal Asiatic Society from 1952 to 1955. Deraniyagala is commemorated in the
scientific names of three species of Sri Lankan reptiles:
Aspidura deraniyagalae,
Lankascincus deraniyagalae, and
Nessia deraniyagalai. ==Family==