20 More Weird Animals You Probably Didn't Know Exist

Lamprey: There are about 38 known extant species of lampreys and five known extinct species. They are classified in three families: two species-poor families in the Southern Hemisphere and one speciose family in the Northern Hemisphere; phylogenetic studies indicate a mid-Mesozoic divergence for all three, underlying the separation of Laurasia and Gondwanaland. The occurrence of modern lampreys only since the Mesozoic (with significant genus & species radiations only in the Cenozoic) contrasts with the Paleozoic origins of the group and its basal nature. 18 species of lampreys engage in this micropredatory lifestyle. Lampreys live mostly in coastal and fresh waters and are found in most temperate regions.