Hayward, B.W., Kawagata, S., Sabaa, A.T., Grenfell, H.R., van Kerckhoven, L., Johnson, K., and Thomas, E., 2012. The last global extinction (Mid-Pleistocene) of deep-sea benthic foraminifera (Chrysalogoniidae, Ellipsoidinidae, Glandulonodosariidae, Plectofrondiculariidae, Pleursostomellidae, Stilostomellidae), their Late Cretaceous-Cenozoic history and taxonomy: Cushman Foundation for Foraminiferal Research Special Publication, v. 43, pl. 21, figs 1-2. Trinidad, early Miocene