Paulsilvella huveorum gen. & sp nov (Corallinaceae, Rhodophyta) from the Holocene of Somalia and Kenya, with a reassessment of Lithothrix antiqua from the Late Pleistocene of Mauritius

A morphological, anatomical and taxonomic account of Paulsilvella Woelkerling, Sartoni & Roddi gen. nov. (Corallinales, Rhodophyta) is provided Paulsilvella belongs to the Corallinaceae, subfamily Lithophylloideae sensu lato (encompassing the Amphiroideae) and differs from other lithophylloid genera (Amphiroa. Ezo, the Lithophyllum-Titanoderma complex, Lithathrix, Tenarea) in possessing nongeniculate protuberant branches that resemble a series of fused beads. The branches are entirely monomerous, with a core region composed of single arching tiers of elongate, columnar cells alternating with two tiers of short, noncolumnar cells. Paulsilvella includes one known extant species, P. huveorum Woelkerling, Sartoni & Boddi sp. nave from Somalia and Kenya, and one known fossil species, P. antiqua (G.F. Elliott) Woelkerling, Sartoni & Boddi comb. nov from the Late Pleistocene of Mauritius. ne latter was originally described as Lithathrix antiqua ('antiquum'). In F. huveorum, the uniporate carposporangial and tetrasporangial conceptacle chambers are largely buried within the thallus, whereas in P. antiqua they protrude above the surrounding thallus surface. A key to species is provided, and generic relationships within the Lithophylloideae are discussed.