The suprageneric classification of the foraminiferal genus Murrayinella and a new species from Japan

Abstract

Japanese species of the foraminiferal genus Murrayinella have a rotaliid aperture that is defined by a foraminal plate and umbilical coverplate. Our observations suggest that this genus must be transferred from the family Glabratellidae to the family Rotaliidae. Its morphological similarity to the genus Schackoinella, as shown by the presence of a peripheral spine on each chamber, must be a result of homeomorphic convergence. Murrayinella never possesses apertural grooves like those of glabratellids. We give a detailed description of the apertural structure of the Japanese species of Murrayinella and formally describe a new species, M. bellula.