Dallina Explained

Dallina is a genus of small to average size lampshells (maximum 35mm long).^[1] It is known since the Miocene.

Description

Small to large, triangular to subquadrangular in outline; rectimarginate to paraplicate; beak erect, without beak ridges; foramen small to large, mesothyrid, attrite, symphytium concave. Hinge teeth small, weak; pedicle collar very short. Cardinalia lamellar with excavate inner and outer hinge plates separated by narrow crural bases; inner hinge plates converging on median septum to form V-shaped septalium; cardinal process not differentiated; median septum low anteriorly, extending beyond midvalve; adult loop teloform.^[2]

Taxonomy

Nine extant species are recognized (though one has recently been synonymized),^[3] these are listed below:

• Dallina septigera (Lovén, 1845), Type species of genus, from northeastern Atlantic.^[4]
• Dallina elongata Hatai, 1940, recorded from Sea of Japan.
• Dallina eltanini Foster, 1974, southern Pacific, near Antarctica.
• Dallina floridana (Pourtalès, 1867), recorded from the Gulf of Mexico and Bahamas.
• Dallina obessa Yabe & Hatai, 1934, recorded from Sea of Japan.
• Dallina parva Cooper, 1981, recorded from northeast Atlantic (Bay of Biscay).^[5]
• Dallina profundis Konjukova, 1957 (junior synonym of Glaciarcula spitzbergensis^[6])
• Dallina raphaelis (Dall, 1970), recorded from off Japan.
• Dallina tasmaniaensis Verhoeff, 2023, southeastern Australia.
• Dallina triangularis Yabe & Hatai, 1934, recorded from off Japan and possibly Lau Ridge.

Notes and References

1. D. . Atkins . 1960 . A note on Dallina septigera (Lovèn), (Brachiopoda, Dallinidae) . Journal of the Marine Biological Association of the United Kingdom . 3 . 1 . 91–99 . 10.1017/s0025315400013126 . dead . https://web.archive.org/web/20141129012621/http://core.kmi.open.ac.uk/download/pdf/6186004.pdf . 2014-11-29 .
2. Book: Moore, R.C.. 1965. Brachiopoda. Geological Society of America/University of Kansas Press. Treatise on Invertebrate Paleontology. Part H., Volume 2. H835. Boulder, Colorado/Lawrence, Kansas. 0-8137-3015-5.
3. Web site: WoRMS - World Register of Marine Species - Dallina Beecher, 1893 . 2023-01-16 . www.marinespecies.org.
4. Zezina . ON . 2010 . Check-list of Holocene brachiopods annotated with geographical ranges of species . Paleontological Journal . 4 . 1176–1199.
5. Cooper . GA . 1981 . Brachiopoda from the Gulf of Gascogne, France (Recent) . Smithsonian Contributions to Paleobiology . 44 . 1–35.
6. Verhoeff . Tristan Joseph . 2023 . New records and descriptions of recent Australian brachiopods (Terebratulida, Dallinidae and Aulocothyropsidae; and Rhynchonellida, Frieleiidae) . Australian Journal of Taxonomy . 11 . 1–29.