A new pseudolepidinid foraminifer, Hanovolepidina browni gen. nov. sp. nov., from the middle Eocene (mid-Lutetian) of Jamaica and its significance

Abstract

The new larger benthic foraminifer, Hanovolepidina browni gen. nov. sp. nov., is described from the Chapelton Formation (mid-Lutetian, middle Eocene, ABZ7) of Jamaica. The genus shows the characteristic transition from a single to double equatorial layer about mid-way across the radius as seen in axial sections that characterises the family Pseudolepidinidae. Equatorial sections show the embryo followed by 4 or 5 spiral rotaliid chambers with the last chamber giving rise to a primary spiral and secondary (counter-) spiral of equatorial chambers. The presence of a long rotaliid stage suggests a more primitive form that Pseudolepidina, and Hanovolepidina gen. nov. differs also from the latter in lacking the extra principal accessory chamber seen in axial section. Hanovolepidina gen. nov. is provisionally suggested as an ancestor of the late Eocene Triplalepidina. The new discovery demonstrates a greater diversity of the family Pseudolpeidinidae in the Caribbean that previously recorded, although occurrences of this family are very restricted stratigraphically suggesting that it may appear in the region due to migration events.