HOUSE, M. R.; ROSS, Charles A.; NORRIS, A. W. Part A, Introduction, Ch. 3, p. 183-290. Treatise on Invertebrate Paleontology, [S. l.], 1979. DOI: 10.17161/dt.v0i0.5530. Disponível em: https://journals.ku.edu/InvertebratePaleo/article/view/5530.. Acesso em: 21 may. 2024.