Pycnoclavella has occasionally been placed in a separate family, Pycnoclavellidae, although phylogenetic studies have recovered it as a relative of Clavelina. In multiple analyses, the monotypic genus Nephtheis appears to branch from within Clavelina.
References
↑Forbes, Edward; Hanley, Sylvanus (1853) [1848]. "Clavelinidæ; or, Social Ascidians". A History of British Mollusca, and Their Shells. Vol.I. Including the Tunicata, and the Families of Lamellibranchiata as far as Cyprinidæ. London: John van Voorst. pp.25–28.
12Shenkar, N., Gittenberger, A., Lambert, G., Rius, M., Moreira Da Rocha, R., Swalla, B.J., Turon, X. (2018). Shenkar N, Gittenberger A, Lambert G, Rius M, Moreira Da Rocha R, Swalla BJ, Turon X (eds.). "Clavelinidae Forbes & Hanley, 1848". Ascidiacea World Database. World Register of Marine Species. Retrieved February 26, 2024.