In 1896, the Belgian-British zoologist George Albert Boulenger combined the species "Dendroaspis angusticeps" with the black mamba ("Dendroaspis polylepis"), a lumping diagnosis that remained in force until 1946, when the South African herpetologist Vivian FitzSimons published a paper after examining approximately 50 eastern green mamba and 85 black mamba specimens. He concluded that the differences in build, scalation, colouration and behaviour warranted splitting them into separate species. The British biologist Arthur Loveridge augmented FitzSimons' work with material from outside South Africa, noting some overlap in scalation but supporting the separation. A 2016 genetic analysis showed the eastern green and black mambas are each others' closest relatives, their common ancestor diverging from a lineage that gave rise to Jameson's mamba ("Dendroaspis jamesoni") and the western green mamba ("Dendroaspis viridis").