A skull and jaw found on a beach in Mackay, Queensland, in 1882, provided the basis for the initial description of this species by H. A. Longman in 1926.

Biologist Joseph C. Moore used this skull, together with the original Mackay specimen, to effectively demonstrate that Longman's beaked whale was a unique species and elevated it to its own genus, Indopacetus.

Dalebout et al. (2003) [5] used a combination of genetic and morphological analyses to identify four further specimens, including a complete adult female with a fetus found in the Maldives in January 2000.

The external appearance and colour pattern of this species was also revealed, and a firm connection was established with the mysterious tropical bottlenose whales that had been sighted in the Indian and Pacific Oceans since the 1960s.

While this paper was in press, a specimen that was first misidentified as a Baird's beaked whale washed up in Kagoshima, Japan, in July 2002.

Additionally, the dorsal fins of adult specimens seem unusually large and triangular for beaked whales, whereas in juveniles they are rather small and swept back.

The rather unusual coloration of the juveniles helped connect the Longman's to the tropical bottlenose whale; both have dark backs behind the blowholes, which quickly shade down to a light gray and then white.

[13] The range of Longman's beaked whales was once considered to be restricted to warmer waters of Pacific, but stranding records in recent years revealed they may migrate further north to sub-Arctic regions such as off Hokkaido.

[15] In the summer and fall of 2010, researchers aboard the NOAA ship McArthur II made two sightings of groups of tropical bottlenose whales off Hawaii.

[23] No records report the whale being hunted, although individuals have been trapped in fishing nets off Sri Lanka and a stranding in Taiwan in 2005 involving a cow-calf pair may have been due to nearby naval exercises.