Humphreysella baltanasiCollection Highlights | Updated 4 years ago Humphreysella baltanasi Photo by Bill Humphreys Welesina is a monotypic genus of minute, half millimetre long, seed shrimps (Ostracoda) of the familiy Thaumatocyprididae found with its relatives only in anchialine caves with a mysterious distribution. Humphreysella baltanasi is known from three anchialine caves (caves affected by marine tides, but lack surface connections with the sea) on Christmas Island, Indian Ocean, the only occurrence of this group of ostracods found on isolated seamounts which rise from abyssal depths. This occurrence challenges the hypothesis that this group spread along the shores of the ancient Tethys Ocean (this existed when the ancient super-continent Gondwana began to separate from Pangaea) but suggests oceanic dispersal thought improbable owing to the subterranean life-style of these animals, lacking a dispersive life stage. Other species in this genus inhabit anchialine caves that occur on or near continents from the Caribbean and Canary Islands.. Surprisingly, Humphreysella baltanasi is not closely related to the other Australian species of the family, the monotypic genus Welesina kornickeri that occurs in a cave in Cape Range in the Ningaloo Coast World Heritage Area. Subterranean Biology Collection View the discussion thread.