Elasmobranchs from the upper Paleocene of Togo

Abstract

Bulk sampling and surface collecting of two glauconitic horizons located in Southern Togo yielded a diverse elasmobranch fauna described here. This fauna includes 30 species dominated by carcharhiniforms (eleven species), myliobatiforms (nine species) and lamniforms (five species); it also comprises three orectolobiforms, whereas the squatiniforms and rhinopristiforms are represented by one species each. Although the poor preservation of the specimens hampered numerous species-level identifications, the vast majority of taxa identified were formerly reported from the Paleocene–Ypresian interval, four of which being exclusively known from the upper Paleocene. This, along with the six associated benthic foraminifera species, indicates a late Thanetian age for the sampled horizons and provide age constraints on a geographically widespread benchmark horizon in Western Africa. The composition of the elasmobranch assemblage shows strong resemblances with upper Paleocene faunas from Morocco and differs markedly from known assemblages from geographically closer localities in Niger and Nigeria, which suggests strong palaeoenvironmental control on the distribution of Thanetian elasmobranch diversity.