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Stromboidea
Rimellidae Stewart, 1927, p. 366 [as Rimellinae]
Comment
- Stewart, 1927 does not give a diagnosis of Rimellinae, but discussed, as part of his comments on Ectinochilus (Cowlitzia) canalifer (Gabb), the whole group of Rimellids, see History and Synonymy below.
Genera of Rimellidae are:
History and Synonymy
1927
Stewart, 1927, p. 367:
- "Ectinochilus is represented on the West Coast by E. macilentus (White) and at Claiborne, Alab., by E. laqueatus (Conrad). These two species differ from the typical mainly by the lack of varices, a character which does not seem to be of great importance in this family. The name Macilentos is available for this small group. E. texanus (Harris) also lacks the varices and may be considered another member of this group. It is very closely related to E. elongatus (Weaver) from Cowlitz, but the outer lip is not so distinctly projected anteriorly. This projection cannot be of much importance for it varies greatly among specimens of Rimella fissurella. If it be desirable to separate E. elongatus and E. texanus from the subgenus or section Macilentos, the name Vaderos is available. Cowlitzia itself is not far from Ectinochilus. It has the same sculpture pattern and the same aperture. The "stromboid sinuosity" is quite well developed on some specimens. The serrated anterior portion of the outer lip, caused by the prolongation of the spiral lines, is the chief character which separates it from Ectinochilus. The type species, which is from Cowlitz, has no varices, but they are often present on the early whorls of E. canalifer. In spite of the presence of varices on E. canalifer, these two species are so closely relared that it would probably be better to recognize this relationship by considering the Cowlitz form a subspecies. The number of axial ribs varies considerably in these forms, but the maximum number is always on the early whorls. The typical form usually has about sixteen while the Cowlitz form usually has twenty. Cowlitzia has not been recognized in other regions and is only represented by E. canalifer and its close allies. While it is tempting to consider the American species generically distinct from typical Ectinochilus because of the general absence of varices, the presence of these varices on the early whorls of some of the specimens of E. canalifer and on "Rimella" smithi Dall, which seems to be an Ectinochilus, is against such an arrangement. Probably some of the European species will be found to be without varices. Ectinochilus retiae (de Gregorio) from the Priabonien (Upper Eocene) is apparently without varices. In general, varices alone are not a generic criterion. ´Rimella´ rugostoma Johnson, from Jackson, Miss. (Upper Eocene) is also, I believe, near Ectinochilus, but it, too, is without varices. Its crenulated aperture is so unique that it seems best to recognize it as a distinct subgenus under the new name Dasyostoma. Ectinochilus need not be confused with Ectinochila, as one writer has done. Typical Rimella does not seem to have reached America, but it extended as far to the East as Java, where it occurs in the Eocene of Nanggulan. Dientomochilus is quite unlike Rimella and its close ally, Ectinochilus. It is doubtful whether the recent so-called Rimellae are related to it. "R." decussata (d'Orb) (Burdigalien) is probably more closely related to Ectinochilus. The one specimen available is without varices."
2009
Diagnosis of the subfamily Rimellinae by Bandel, 2009, p. 124:
- "Shell shape is spindle-like with whorls of the teleoconch ornamented by axial ribs and variable varices. The body whorl is of about the same height as the spire. The aperture is elongate with open short siphonal canal. Its outer margin is commonly elongate and pointed. The apical end of the outer lip forms together with the continuation of the callus of the inner lip a narrow canal that continues onto the spire. The outer lip may or may not have a distinct stromboid notch, that is a sinus next to the siphon."
Status
- Comment of G. Kronenberg:
- "At present Burger & Kronenberg do not recognise (yet) the family Rimellidae Stewart, 1927. The name [as a family level taxon] is available, which does not necessarily mean that it should be used in this fashion, or used at all. Living species (Varicospira spp.) have morphological [shell, operculum, anatomy] characters that look like a mixture of characters found in Strombidae, Rostellariidae and Seraphsidae. Should future research indicate that this is a true clade within the Stromboidea, there are a few options left:
- a family of its own
- a subfamily within Strombidae (or perhaps Seraphsidae, or -less plausible- Rostellariidae)
- a tribus within a not yet defined subfamily."
References
- Stewart, R. B. 1927. Gabb’s California fossil type gastropods. Proceedings of the Academy of Natural Sciences of Philadelphia 78(for 1926):287–447, pls. 20–32.
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