Retusa truncatula, from here.

Belongs within: Euopisthobranchia.

The Retusidae, canoe shells, are a family of infaunal cephalaspid gastropods characterised by the lack of a radula. Instead, their diet of forams and minute molluscs is processed by gizzard plates.

<==Retusidae [Retusacea, Retusoidea]
    |--Ventomnestia girardi (Audouin 1827) [=Bulla girardi, Alicula girardi, Cylichna girardi]BD86
    `--Retusa Brown 1827 [Crypsibranchia]BR05
         |  i. s.: R. amphizosta (Watson 1883) [=Utriculus amphizosta]H09
         |         R. aupouria Powell 1937P61
         |         R. complanata (Watson 1883) [=Utriculus complanatus]H09
         |         R. decapitata Dall 1896F27
         |         R. mamillataM62
         |         R. murdochi (Suter 1913) [=Cylichna simplex Murdoch & Suter 1906 non Tornatina simplex Adams 1850]D56
         |         R. nitida (Adams 1850) [=Bulla nitida]H09
         |         R. oruaensis (Webster 1908)P61 (see below for synonymy)
         |         R. ovataC60
         |         R. pachys (Watson 1883)P61 [=Utriculus (Tornatina) pachysD56]
         |         R. pertenuis Mighels 1843O27
         |         R. semen Reeve 1856O27
         |         R. simillima (Watson 1883) [=Utriculus simillimus]H09
         |         R. succinctaGAS03
         |--R. (Retusa)O27
         |    |--*R. (R.) obtusa (Montagu 1803)P61, O27 (see below for synonymy)
         |    `--R. (R.) truncatula (Bruguiere 1772)O27 (see below for synonymy)
         |--R. (Coleophysis Fischer 1883)O27
         |    `--R. (C.) harpa Dall 1871O27
         `--R. (Sulcularia Dall 1920)O27
              `--R. (S.) xystrum Dall 1919O27

Retusa oruaensis (Webster 1908)P61 [=Tornatina oruaensisD56, incl. R. biplicata Suter 1909P61, T. biplicataD56, R. charlottae Suter 1909P61, T. charlottaeD56, R. cookiana Suter 1909P61, Tornatina cookianaD56, T. decapitata Suter 1909F27, Retusa decapitata non Dall 1896F27, R. suteri Finlay 1927P61, R. tenuilirata Suter 1909P61, Tornatina tenuilirataD56]

*Retusa (Retusa) obtusa (Montagu 1803)P61, O27 [=Bulla obtusaP61; incl. R. alba Kanmacher 1798 (nom. rej.)D56, R. discorsD56, R. plicataD56]

Retusa (Retusa) truncatula (Bruguiere 1772)O27 [=Bulla truncatulaO27, B. truncata (l. c.)BR17, Cylichna truncata (l. c.)BR17]

*Type species of generic name indicated


[BD86] Barash, A., & Z. Danin. 1986. Further additions to the knowledge of Indo-Pacific Mollusca in the Mediterranean Sea (Lessepsian migrants). Spixiana 9 (2): 117–141.

[BR05] Bouchet, P., & J.-P. Rocroi. 2005. Classification and nomenclator of gastropod families. Malacologia 47 (1–2): 1–397.

[BR17] Bouchet, P., J.-P. Rocroi, B. Hausdorf, A. Kaim, Y. Kano, A. Nützel, P. Parkhaev, M. Schrödl & E. E. Strong. 2017. Revised classification, nomenclator and typification of gastropod and monoplacophoran families. Malacologia 61 (1–2): 1–526.

[C60] Cox, L. R. 1960. Gastropoda: general characteristics of Gastropoda. In: Moore, R. C. (ed.) Treatise on Invertebrate Paleontology pt I. Mollusca 1: Mollusca—General Features, Scaphopoda, Amphineura, Monoplacophora, Gastropoda—General Features, Archaeogastropoda and some (mainly Paleozoic) Caenogastropoda and Opisthobranchia pp. I84–I169. Geological Society of America, and University of Kansas Press.

[D56] Dell, R. K. 1956. The archibenthal Mollusca of New Zealand. Dominion Museum Bulletin 18: 1–235.

[F27] Finlay, H. J. 1927. New specific names for austral Mollusca. Transactions and Proceedings of the New Zealand Institute 57: 488–533.

[GAS03] Gulbin, V. V., I. S. Arzamastsev & V. M. Shulkin. 2003. Ecological monitoring of the water area of Port Vostochnyi (Wrangel Bay) in the Sea of Japan (1995–2002). Russian Journal of Marine Biology 29 (5): 284–295.

[H09] Hedley, C. 1909. The Marine Fauna of Queensland: Address by the President of Section D. Australasian Association for the Advancement of Science: Brisbane.

[M62] Monniot, F. 1962. Recherches sur les graviers a Amphioxus de la région de Banyuls-sur-Mer. Vie et Milieu 13: 231–322.

[O27] Oldroyd, I. S. 1927. The Marine Shells of the West Coast of North America vol. 2 pt 1. Stanford University Press: Stanford University (California).

[P61] Powell, A. W. B. 1961. Shells of New Zealand: An illustrated handbook 4th ed. Whitcombe and Tombs Limited: Christchurch.


  1. Reading this list my brains tried to cope with all the codes, but this publication is unnecessary complicated abacadabra, too many un-explained or even in dictionaries un-detectable (personal? words, probably jargon only clear to the author. I can only by reading first the list of authors, re-route numbers and letter codes to authors. Why not mention them direct in your diagram? More reader friendly.I love the pictures though.

    1. Why not mention them direct in your diagram?

      Primarily a question of space; I can't really make each entry in the tree longer than a single line without making the tree too difficult to read. There's also the personal convenience that the codes are much easier to edit (I do go back and update and/or modify entries over time) and I do have only so much time for this project. There are a number of things that would be done differently if this was a professional production, I will admit.

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