LEUCOSPHAERINAE, Taylor & Glover & Smith & Dyal & Williams, 2011

Taylor, John D., Glover, Emily A., Smith, Lisa, Dyal, Patricia & Williams, Suzanne T., 2011, Molecular phylogeny and classification of the chemosymbiotic bivalve family Lucinidae (Mollusca: Bivalvia), Zoological Journal of the Linnean Society 163 (1), pp. 15-49 : 28-33

LEUCOSPHAERINAE NEW SUBFAMILY

This group of species forms a distinct, well-supported clade in the molecular analysis, but there are no clear and consistent morphological characters that unite the group. We propose a new subfamily name Leucosphaerinae for this clade, based on the genus Leucosphaera . Unfortunately, an obvious subfamily name based on Anodontia could not be used because of the prior use for the freshwater mussel Anodonta .

Lucinids in this clade have no radial shell sculpture, cardinal teeth are usually small or absent, lateral teeth are lacking, whereas the lunule is prominent and highly asymmetrical in Pseudolucinisca , taxa in Table 1.

Lucinidae Fleming, 1828

PEGOPHYSEMINAE new subfamily Taylor & Glover herein

Pegophysema Stewart, 1930 ( Lucina schrammi Crosse, 1876 )

Cavatidens Iredale, 1930 ( Cavatidens omissa Iredale, 1830 )

Cryptophysema Taylor & Glover, 2005 ( Lucina vesicula Gould, 1850 )

Euanodontia Taylor & Glover, 2005 ( Lucina ovum Reeve, 1850 )

Loripinus Monterosato, 1883 ( Lucina fragilis Philippi, 1836 )

Unconfirmed:

Afrophysema Taylor & Glover, 2005 ( Cryptodon eutornus Tomlin, 1921 )

Bythosphaera Taylor & Glover, 2005 ( Cryptodon watsoni Smith, 1885 )

Meganodontia Bouchet & Cosel 2004 ( Meganodontia acetabulum Bouchet & Cosel, 2004 )

LEUCOSPHAERINAE new subfamily Taylor & Glover herein

Leucosphaera Taylor & Glover, 2005 ( Lucina (Loripinus) salamanensis Thiele & Jaeckel, 1931 )

Anodontia Link, 1807 ( Anodonta alba Link, 1807 )

Dulcina Cosel & Bouchet, 2008 ( Dulcina guidoi Cosel & Bouchet, 2008 )

Pseudolucinisca Chavan, 1959 ( Lucina lacteola Tate, 1897 )

Undescribed genera – UGS-1, UGS-2. UGS-3

Unconfirmed:

Afrolucina Cosel, 2006 ( Afrolucina discontinua Cosel, 2006 )

Alucinoma Habe, 1958 ( Alucinoma soyae Habe, 1958 )

Callucina Dall, 1901 ( Lucina radians Conrad, 1841 )

Epidulcina, Cosel & Bouchet, 2008 ( Epilucina delphinae Cosel & Bouchet, 2008 )

Minilucina, Cosel & Bouchet, 2008 ( Minilucina coriolis Cosel & Bouchet, 2008 )

Neophysema Taylor & Glover, 2005 ( Neophysema aphanes Taylor & Glover, 2005 )

Semelilucina Cosel & Bouchet, 2008 ( Semelilucina semeliformis Cosel & Bouchet, 2008 )

Tinalucina Cosel, 2006 ( Tinalucina aequatorialis Cosel, 2006 )

MYRTEINAE Chavan, 1969

Myrtea Turton, 1822 ( Venus spinifera Montagu, 1803 )

Gloverina Cosel & Bouchet, 2008 ( Gloverina vestifex Cosel & Bouchet, 2008 )

Notomyrtea Iredale, 1924 ( Myrtea botanica Hedley, 1918 )

Unconfirmed:

Elliptiolucina Cosel & Bouchet, 2008 ( Elliptiolucina magnifica Cosel & Bouchet, 2008 )

Eulopia Dall, 1901 ( Lucina sagrinata Dall, 1886 )

Gonimyrtea Marwick, 1929 ( Loripes concinna Hutton, 1885 )

Graecina Cosel, 2006 ( Graecina karinae Cosel, 2006 )

Jorgenia Taylor & Glover, 2009a ( Jorgenia louisiana Taylor & Glover, 2009a )

Myrtina, Glover & Taylor, 2007 ( Myrtina porcata Glover & Taylor, 2007 )

Poumea Glover & Taylor, 2007 ( Poumea coselia Glover & Taylor, 2007 )

Rostrilucina, Cosel & Bouchet, 2008 ( Rostrilucina garuda Cosel & Bouchet, 2008 )

Solelucina Glover & Taylor, 2007 ( Solelucina koumacia Glover & Taylor, 2007 )

Taylorina, Cosel & Bouchet, 2008 ( Taylorina alata Cosel & Bouchet, 2008 )

MONITILORINAE new subfamily Taylor & Glover herein

Monitilora Iredale, 1930 ( Lucina ramsayi Smith, 1885 )

Unconfirmed:

Prophetilora Iredale, 1930 ( Prophetilora arizela Iredale, 1930 )

FIMBRIINAE Nicol, 1950

Fimbria Mühlfeld, 1811 ( Fimbria magna Mühlfeld, 1811 )

CODAKIINAE Korobokov, 1954

Codakia Scopoli 1777 ( Venus orbicularis Linnaeus, 1758 )

Ctena Mörch, 1861 ( Codakia mexicana Dall, 1901 )

Epicodakia Iredale, 1930 ( Epicodakia consettiana Iredale, 1930 )

Epilucina Dall, 1901 ( Lucina californica Conrad, 1887 )

Lucinoma Dall, 1901 ( Lucina filosa Stimpson, 1851 )

Unconfirmed:

Epilucina Dall, 1901 ( Lucina californica Conrad, 1887 )

LUCININAE Fleming, 1828

Austriella Tenison-Woods, 1881 ( Austriella sordida Tenison-Woods, 1881 )

Bathyaustriella Glover, Glover et al. 2004 ( Bathyaustriella thionipta Glover et al., 2004 )

Bretskya Glover & Taylor, 2007 ( Bretskya scapula Glover & Taylor, 2007 )

Cardiolucina Sacco, 1901 ( Cardium agassizi Michelotti, 1839 )

Cavilinga Chavan, 1937 ( Lucina trisulcata Conrad, 1841 )

Chavania Glover & Taylor, 2001 ( Lucina erythraea Issel, 1869 )

Discolucina Glover & Taylor, 2007 ( Lucina virginae Deshayes, 1832 )

Divalinga Chavan, 1951 ( Lucina quadrisulcata d’Orbigny, 1846 )

Divaricella Martens, 1880 ( Lucina (Divaricella) angulifera Martens, 1880

Funafutia Glover & Taylor, 2001 ( Lucina levukana Smith, 1885 )

Indoaustriella Glover et al., 2008 ( Lucina plicifera Adams, 1855 )

Lepidolucina Glover & Taylor, 2007 ( Lucina venusta Philippi, 1847 )

Loripes Poli, 1791 ( Loripes lacteus Poli, 1791 )

Lucina Bruguière, 1797 ( Venus pensylvanica Linnaeus, 1758 )

Lucinella Monterosato, 1883 ( Lucina commutata Philippi, 1836 )

Lucinisca Dall, 1901 ( Lucina nassula Conrad, 1846 )

Parvilucina Dall, 1901 ( Lucina tenuisculpta Carpenter, 1864 )

Phacoides Gray, 1847 ( Tellina pectinata Gmelin, 1791 )

Pillucina Pilsbry, 1921 ( Pillucina spaldingi Pilsbry, 1921 )

Radiolucina Britton, 1972 ( Phacoides amiantis Dall, 1901 )

Rasta Taylor & Glover, 2000 ( Rastafaria thiophila Taylor & Glover, 1997 )

Stewartia Olsson & Harbison, 1953 ( Lucina anodonta Say, 1824 )

Troendleina Cosel & Bouchet, 2008 ( T. marquesana Cosel & Bouchet, 2008 )

Wallucina Iredale, 1930 ( Lucina jacksoniensis Smith, 1885 )

Unconfirmed:

Barbierella Chavan, 1938 ( Lucina barbieri Deshayes, 1857 )

Bourdotia Dall, 1901 ( Lucina bourdoti Cossmann, 1882 )

Cavilucina Fischer, 1887 ( Lucina sulcata Lamarck, 1806 )

Divalucina Iredale, 1936 ( Cyclas cumingi A. Adams, 1864 )

Falsolucinoma Cosel, 2006 ( Lucina leloeuffi Cosel, 1989 )

Ferrocina Glover & Taylor 2007 ( Ferrocina multiradiata Glover & Taylor, 2007 )

Gibbolucina Cossmann, 1904 ( Venus callosa Lamarck, 1806 )

Here Gabb, 1866 ( Lucina richtofeni Gabb, 1866 )

Joellina Cosel, 2006 ( Joellina dosiniformis Cosel, 2006 )

Keletistes Oliver, 1986 [ Loripes (Keletistes) rhizoecus Oliver, 1986 ]

Lamellolucina Taylor & Glover, 2006 ( Lamellolucina pilbara Taylor & Glover, 2002 )

Lamylucina Cosel, 2006 [ Phacoides (Lucinoma) gainei Lamy, 1920 ]

Liralucina Glover & Taylor, 2007 ( Phacoides sperabilis Hedley, 1909 )

Nevenulora Iredale, 1930 ( Lucinida hilaira Hedley, 1917 )

Parvidontia Glover & Taylor, 2007 ( Parvidontia laevis Glover & Taylor, 2007 )

Pleurolucina Dall, 1901 ( Lucina leucocyma Dall, 1886 )

Plicolucina Glover et al., 2004 ( Plicolucina flabellata Glover et al., 2004 )

Pompholigina Dall, 1901 ( Lucina gibba Gray, 1825 )

? Milthinae Chavan, 1969

Miltha H. & A. Adams, 1857 ( Lucina childreni Gray, 1824 )

Eomiltha Cossmann, 1912 ( Lucina contorta Defrance, 1823 )

Genera listed as ‘Unconfirmed’ are without molecular confirmation of position. Type species of genera in parentheses.

Leucosphaera , and Dulcina . The clade includes Anodontia alba from the western Atlantic, Pseudolucinisca lacteola from southern Australia (Glover & Taylor, 2008 ), and the small, semitransparent, thinshelled Leucosphaera , a common but little recorded lucinid in offshore fine sediments of the Indo-West Pacific, and previously confounded with juvenile ‘ Anodontia ’ (see Taylor & Glover, 2005; Glover & Taylor, 2007 ). Additionally, the group includes some deeper water forms including species of Dulcina , together with three undescribed species and genera (UGS-1, UGS-2, and UGS-3).

It was initially surprising that Anodontia alba ( Figs 6B, 7F ) did not group with the superficially similar taxa, usually called ‘ Anodontia ’ (Williams et al., 2004), now included here in the Pegophyseminae (see above). Anodontia alba and the eastern Pacific sister species Anodontia edentuloides (Verrill, 1870) , however, differ from pegophysemines in both shell characters and internal anatomy, for example lacking the mantle septum and digitate mantle gills ( Taylor & Glover, 2005). The Eocene (Ypresian) species Eophysema cossmanni Chavan, 1941 , from the Paris Basin, classified by Strougo (1975) into a new genus Rawya (type species Lucina pharaonis Bellardi, 1854 ), has many characters of Anodontia alba , but, in addition, has small cardinal teeth ( Fig. 6A). We regard this species as a possible early representative of the Anodontia alba lineage. Cardinal teeth are absent in recent species, but they possess a smooth triangular area beneath the umbo (‘aire dentaire’ of Chavan, 1937 –1938), corresponding to the position of teeth in dentate taxa. From this evidence we suggest that the Anodontia alba clade was separate from the Pegophyseminae at least by the mid-Eocene. The chronogram ( Fig. 5 ) suggests a much older divergence of the clades in the late Cretaceous, at 100 ± 25 Ma.

Other genera in this clade have a poor or unrecognized fossil record, including the laterally compressed, edentulous deep-water Dulcina and Alucinoma ( Cosel & Bouchet (2008). Two Miocene species, Lucina strigosa Michelotti, 1861 and Lucina michelotti Mayer, 1858 were assigned to Pseudolucinisca by Chavan (1959), but these species possess lateral teeth, unlike any living forms (Glover & Taylor, 2008 ).

Figures

Figure 5. Chronogram generated by BEAST for species of Lucinidae, and calibrated using ten fossil records. The position of each calibration point is indicated by the numbers in circles (see the Material and methods and Discussion sections for details about the fossils). Error bars for node ages are the 95% highest posterior density intervals; clades with less than 50% support have no error bars; the root node has node bar trimmed by 50% for clarity. New subfamily divisions are shown on the right-hand side, with details presented in Table 3.

Figure 7. Representatives of the new subfamily Leucosphaerinae including some of the sequenced specimens. Not to scale. L = actual shell lengths. A. Leucosphaera cf. diaphana Glover & Taylor 2007. Shell from same station as sequenced specimen. Ubajan, Bohol Island, Philippines. PANGLAO 2004, st. S27, 9°41.5′N, 123°51.0′E, 12 m (MNHN). L = 4.9 mm. B. Leucosphaera diaphana Glover & Taylor 2007, holotype, New Caledonia (MNHN). L = 6.0 mm. C. Pseudolucinisca lacteola (Tate, 1897) (syntype of Lucina concentrica Reeve, 1850, St Vincent’s Gulf, South Australia (BMNH 1870.10.26.33). L = 21.5 mm. D. Undescribed genus and species (UGS-1). Shells from same station as sequenced specimen figured in E (MNHN). L = 10.3 mm. E. Undescribed genus and species (UGS-1). Maribojoc Bay, Bohol Sea, PANGLAO 2005, st CP 2397, 9°34.9′N, 123°41.7′E. 642–669 m (MNHN IM-2009-10373). L = 7.0 mm. F. Anodontia alba Link 1807 ‘West Indies’ (BMNH 1963476-2). L = 53mm. G. Dulcina sp. Bohol Sea, Philippines. PANGLAO 2005, st. CP 2335, 9°34.3′N, 123°37.8′E. 729–733 m (MNHN IM-2009-10371). L = 17 mm. H. Dulcina karubari Cosel & Bouchet, 2008. Maribojoc Bay, Bohol Sea, Philippines. PANGLAO 2005, st. CP 2331, 9°39.2′N, 123°47.5′E. 255–268 m (MNHN IM-2009-10372). L = 16 mm. I. Dulcina karubari Cosel & Bouchet, 2008. Holotype, Tanimbar Islands, Indonesia. KARUBAR, st. CP 63, 8°00′S, 132°58′E. 215 m (MNHN 20729). Right valve to show internal details of shell. L = 27.9 mm. J. Undescribed genus and species (UGS-3). Chesterfield Bank, New Caledonia (MNHN IM-2009-10376). L = 23.5 mm. K. Undescribed genus and species (UGS-2), shell from same station as sequenced specimen. Manga, Bohol Island, Philippines. PANGLAO 2004, st. S20, 9°41.8′N, 123°51.1′E. 10 m specimen. L = 4.0 mm.