identifier	taxonID	type	CVterm	format	language	title	description	additionalInformationURL	UsageTerms	rights	Owner	contributor	creator	bibliographicCitation
03BE87C80E3D52255341FCF54331F206.text	03BE87C80E3D52255341FCF54331F206.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Jukesena foveolata (Dell 1964)	<div><p>WHAT ABOUT  J. FOVEOLATA ?</p><p>Jukesena foveolata was described by Cooper &amp; Preston (1910) based on specimens collected at the Falkland Islands. After its original description, only Dell (1964) reported additional material of this species, also coming from the type locality. Even when rarely sampled, the generic placement of  J. foveolata has been controvertial. Originally placed in the genus  Psephis (Veneroidea) by Cooper &amp; Preston (1910), the species was subsequently mentioned under the  Gomphina subgenus  Acolus Jukes-Brown, 1913 (Veneroidea) by Melvill &amp; Standen (1914). Iredale (1915) noticed that at the genus level  Acolus Jukes-Brown, 1913 is preoccupied by  Acolus Foerster, 1856 ( Hymenoptera). Consequently, he proposed  Jukesena as a replacement name for the former. However, the name  Jukesena remained largely disregarded, and ‘  Gomphina (Acolus) ’ continued to be used in subsequent publications (e.g. Carcelles &amp; Williamson, 1951; Powell, 1951). Powell (1960) recovered the usage of  Jukesena (as a subgenus of  Gomphina), subsequently followed by Dell (1964). Despite the different (sub)generic placements for the species, until now its inclusion in  Veneridae (Veneroidea) had never been questioned, probably because the species remained known only from its shell morphology for more than a century.</p><p>As part of the present study, we had the chance to study one live-collected specimen of this species from Patagonia. This specimen shows great morphological and anatomical similarities to  Cyamioidea, particularly by the presence of the follicular epithelium, embryos attached to the gill filaments of the parental specimen by a stalk, and tentacles at the posterior part of the mantle margin. These characters, together with the molecular evidence obtained here (from both 16S and 28S markers), allow us to establish the placement of</p></div>	https://treatment.plazi.org/id/03BE87C80E3D52255341FCF54331F206	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Zelaya Marina Güller, Diego G.;Ituarte, Cristián	Zelaya Marina Güller, Diego G., Ituarte, Cristián (2020): Filling a blank in bivalve taxonomy: an integrative analysis of Cyamioidea (Mollusca: Bivalvia). Zoological Journal of the Linnean Society 190: 558-591
03BE87C80E3D5227514EFF1242FEF0EC.text	03BE87C80E3D5227514EFF1242FEF0EC.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Jukesena foveolata (Dell 1964)	<div><p>J. foveolata in  Cyamioidea and that the species is not closely related to  Gomphina undulosa (type species of  Gomphina) or other Veneroidea, as previously thought.</p><p>Considering the number, morphology and degree of development of cardinal teeth, the presence of an internal and an external ligament, the numerous tentacles at the posterior part of mantle margin, the long byssus groove and the left and right inner demibranchs being posteroventrally fused by a short distance,  J. foveolata shows greater similarity to  Cyamiidae than to  Gaimardiidae . However, it differs clearly from all other  Cyamiidae studied herein by having both inhalant and exhalant apertures projected as siphons and crowned by tentacles, related to the presence of a well-marked pallial sinus, and by having the series of posterior tentacles arising from the distal part of the middle mantle fold instead of arising from the base of the inner mantle fold as in  Cyamiocardium,  Cyamium,  Gaimardia,  Heteromactra,  Kidderia,  Pseudokellya and  Ptychocardia . Furthermore, the anterior labial palps are subquadrate, and the foot appears to lack a differentiated stalk, a condition not seen in any other  Cyamiidae . In contrast, unlike any other  Cyamiidae and  Gaimardiidae, the foot of  J. foveolata is compressed and has a narrow base. The molecular information obtained from the two markers considered herein does not allow us to be conclusive whether  J. foveolata is a  Cyamiidae or belongs to a different family in  Cyamioidea . It is interesting to note the similarity in shell morphology and gross anatomy of this species to  Cyamiomactra problematica (type species of the genus), although the restricted knowledge of that species does not allow us to be conclusive regarding whether both taxa should be reunited into the same genus.</p><p>OTHER TAXA PREVIOUSLY ASSIGNED TO  CYAMIOIDEA</p><p>Besides the taxa considered above, 11 other (sub) genera ( Costokidderia,  Cyamiomactra,  Cyamionema, Dicranodesma,  Eugaimardia,  Legrandina,  Lutetina,  Neogaimardia,  Perrierina, Progaimardia and  Reloncavia) were previously mentioned in the literature as belonging to either  Cyamiidae or  Gaimardiidae, and seven other families ( Bernardinidae,  Basterotiidae,  Galatheavalvidae,  Juliidae,  Neoleptonidae,  Sportellidae and  Turtoniidae) were assigned to  Cyamioidea /Gaimardioidea.</p><p>TAXA HERE REGARDED AS PROBABLY BELONGING TO  CYAMIOIDEA</p><p>Reloncavia (type species:  Kingiella chilenica Soot-Ryen, 1959)</p><p>The hinge of this genus (figured by Soot-Ryen, 1959: figs 14, 15; and Chavan, 1969: fig. E39, 3 b, 3c) shows great similarity with that of  Cyamium . Soot-Ryen (1957, 1959) described the gross anatomy of  Reloncavia chilenica, reporting the presence of a large pedal opening and two smaller (inhalant and exhalant) openings, a large foot, small labial palps and small posterior ‘papillae’. Gallardo (1993) described how ‘each embryo is contained in a small capsule attached to a branchial filament by a short peduncle’. The ‘capsule’ and ‘peduncle’ are likely to correspond to the follicular epithelium recognized here as diagnostic for  Cyamioidea . All morphological and anatomical characters suggest  Reloncavia to be a  Cyamiidae .</p><p>Cyamiomactra (type species:  Cyamiomactra problematica Bernard, 1897)</p><p>The description of this genus was not given separately from that of the type species. Bernard (1897) emphasized the similarity of this genus to  Cyamium, pointing out as the main differences the shell outline (‘  Cyamium is much more elongated’) and the presence of posterior cardinal teeth in the left valve (regarded as absent in  Cyamium, but as a consequence of an erroneous interpretation of the hinge; see above). After studying the gross anatomy of  Cyamiomactra problematica, Ponder (1971) concluded that it ‘agrees closely with  Cyamium antarcticum ’. In fact, the author considered  Cyamiomactra as a subgenus of  Cyamium . In its shell outline,  Cyamiomactra does not show great morphological differences from  Cyamium .</p><p>Perrierina (type species:  Perrierina taxodonta Bernard, 1897)</p><p>The genus has the same number, morphology and arrangement of cardinal teeth as  Cyamiomactra problematica . This fact was pointed out in its description (Bernard, 1897) and ratified by subsequent authors (e.g. Fleming, 1948). The only difference is the presence of several lateral ‘crests’ along the dorsal margin in  Perrierina (diversely referred as lateral teeth, marginal denticles, lateral lamellae, taxodontlike laterals or taxodont lamellae). Ponder (1971) studied the gross anatomy of the type species of  Perrierina, which, although similar to that of  Cyamium and  Cyamiomactra, was described as lacking a byssus groove in the foot and tentacles at the posterior end of the mantle margin (two characters present in the other species of  Cyamioidea studied herein). Despite that, Ponder (1971) concluded that  Perrierina ‘is clearly derived from a  Cyamium or  Cyamiomactra - like ancestor’. In addition, he considered  Legrandina to be a subgenus of  Perrierina . We have no additional evidence to confirm or reject Ponder’s (1971) opinion. Consequently, we follow the family placement proposed by Ponder (1971) for those taxa.</p><p>Neogaimardia (type species:  Kellia rostellata Tate, 1889)</p><p>Since its description,  Neogaimardia has been considered a member of the  Gaimardiidae . Odhler (1924) compared it with  Gaimardia, and Ponder (1971) and Huber (2010) considered it to be a subgenus of  Gaimardia . Morton (1979) provided valuable anatomical information of  Neogaimardia finlayi Powell, 1933, a species very similar to  N. rostellata . The main differences of  Neogaimardia (with respect to  Gaimardia) are the presence of a short internal ligament, well-defined posterior lateral teeth, accessory ‘marginal teeth’ and the presence of only one (the inner) demibranch at each side. Furthermore, judging from Morton’s (1979) figure 5, the laterofrontal cilia of ctenidia in  Neogaimardia do not form hornlike structures. In all other aspects,  Neogaimardia appears similar to  Gaimardia . In fact, both taxa also have similar modes of life, attached to floating algae. Odhler (1924) described how  N. rostellata brood ‘large eggs … in follicles which are formed as in  Pseudokellya (cf. Pelseneer, 1903)’. Considering the very peculiar structure described by Pelseneer (1903), it seems clear that Odhner’s description refers to the follicular epithelium considered here as diagnostic for  Cyamioidea .</p><p>Progaimardia (type species: Modiolarca minutissima Iredale, 1908)</p><p>The general shell morphology of the type species closely resembles that of  Gaimardia . In fact, this genus was originally proposed as a subgenus of  Gaimardia, from which it was distinguished by the presence of a large, internal ligament and a strong hinge plate, bearing one large tooth in each valve and moderately long anterior and posterior teeth (Ponder, 1971). No additional anatomical or reproductive information is available for this genus.</p><p>Eugaimardia (type species:  Neogaimardia perplexa Cotton, 1931)</p><p>Cotton (1931a) described a new species of gaimardiid, erecting  Neogaimardia as a new genus for its placement, but had overlooked that this name was preoccupied by  Neogaimardia Odhler, 1924 . Cotton (1931b) proposed  Eugaimardia as a replacement name for the former. Cotton (1931a) distinguished his new genus from  Gaimardia by the absence of a concavity in the ventral margin and by its different ‘dentition of the hinge’, namely the presence of a ‘U-shaped tooth, and a small tooth between the arms of the U’ in the right valve. The morphology of the teeth he described does not appear as discrepant from the one we find in  G. trapesina . Furthermore, in  G. trapesina, the concavity of the ventral margin proves to be variable among specimens. Thus, from a morphological point of view, we find no evidence to consider  Eugaimardia to be distinct from  Gaimardia . Unfortunately, nothing is known about the anatomy or reproduction of  Eugaimardia perplexa . Despite that,  Eugaimardia was considered a valid genus by Huber (2010).</p><p>Costokidderia (type species:  Kidderia costata Odhler, 1924)</p><p>The type species of this genus has a shell outline that closely resembles that of  Kidderia . Odhler (1924) described for that species the presence of strong radial sculpture and strong cardinals. The first of these characters led Finlay (1926) to propose the genus  Costokidderia, a name currently regarded as a subgenus of  Kidderia (e.g. Ponder, 1971).</p><p>Cyamionema (type species:  Cyamium (Cyamionema) decoratum Melvill &amp; Standen, 1914)</p><p>Despite having originally been compared with  Cyamium, the general shell outline and morphology of the hinge teeth of  Cyamium decoratum appear more similar to those of  K. minuta (type species of  Kidderia) than to those of  Cyamium antarcticum (type species of  Cyamium).  Cyamionema decoratum differs from  Cyamium antarcticum (and from other  Cyamiidae) by lacking an internal ligament, by having only one tooth in the left valve and by the presence of thin radial sculpture in the central part of the shell (Melvill &amp; Standen, 1914). The significance of these differences and the relationship of  Cyamionema to  Kidderia deserve further studies. Scarlato &amp; Starobogatov (1979) proposed a new family,  Cyamionematidae (in  Galeommatoidea), based on this genus.  Cyamionema appears listed as a subgenus of  Kidderia by Huber (2010).</p><p>TAXA HERE EXCLUDED FROM  CYAMIOIDEA</p></div>	https://treatment.plazi.org/id/03BE87C80E3D5227514EFF1242FEF0EC	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Zelaya Marina Güller, Diego G.;Ituarte, Cristián	Zelaya Marina Güller, Diego G., Ituarte, Cristián (2020): Filling a blank in bivalve taxonomy: an integrative analysis of Cyamioidea (Mollusca: Bivalvia). Zoological Journal of the Linnean Society 190: 558-591
03BE87C80E3F5227514EFDDD4413F794.text	03BE87C80E3F5227514EFDDD4413F794.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Juliidae Smith 1885	<div><p>Juliidae Smith, 1885</p><p>The family was originally described as belonging to  Bivalvia (Smith, 1885), where it was allocated to Gaimardioidea by Thiele (1934). However, the current conception is that  Juliidae is a family of sacoglossan gastropods (Le Renard et al., 1996; Bouchet et al., 2017).</p></div>	https://treatment.plazi.org/id/03BE87C80E3F5227514EFDDD4413F794	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Zelaya Marina Güller, Diego G.;Ituarte, Cristián	Zelaya Marina Güller, Diego G., Ituarte, Cristián (2020): Filling a blank in bivalve taxonomy: an integrative analysis of Cyamioidea (Mollusca: Bivalvia). Zoological Journal of the Linnean Society 190: 558-591
03BE87C80E3F522752D6FA7D423FF3CB.text	03BE87C80E3F522752D6FA7D423FF3CB.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Lutetina Velain 1877	<div><p>Lutetina (type species:  Lutetina antarctica</p><p>Vélain, 1877)</p><p>Lutetina was included in  Cyamiidae by Chavan (1969). Bernard (1898: fig. 1) properly figured the hinge plate of the type species, which shows a morphology and arrangement of teeth consistent with those present in  Neoleptonidae . A similar conclusion was reached by Salas &amp; Gofas (1998), who considered  Lutetina as a possible synonym of  Neolepton .</p></div>	https://treatment.plazi.org/id/03BE87C80E3F522752D6FA7D423FF3CB	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Zelaya Marina Güller, Diego G.;Ituarte, Cristián	Zelaya Marina Güller, Diego G., Ituarte, Cristián (2020): Filling a blank in bivalve taxonomy: an integrative analysis of Cyamioidea (Mollusca: Bivalvia). Zoological Journal of the Linnean Society 190: 558-591
03BE87C80E3F5227514EFCCD459EF21E.text	03BE87C80E3F5227514EFCCD459EF21E.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Neoleptonidae Thiele 1934	<div><p>Neoleptonidae Thiele, 1934</p><p>The position of this family has been controversial. Some authors included it in  Cyamioidea (e.g. Thiele, 1934; Chavan, 1969; Powell, 1979; Sabelli et al., 1990; Morton, 2015), whereas others regarded it as a (possible) Veneroidea (Ockelmann in Bowden &amp; Heppell, 1968; Salas &amp; Gofas, 1998). Mikkelsen et al. (2006) pointed out that this family joined  Veneridae in the traditional morphology tree, but fell outside Veneroidea in their all-morphology analysis. The cardinal teeth in  Neolepton appear translocated with respect to the condition present in  Cyamiocardium,  Cyamiomactra,  Cyamium,  Heteromactra and  Jukesena (compare Figs 1A, C, D, F, G, I, J, L, 2A, C of the present study with Salas &amp; Gofas, 1998: figs 1, 2 or Zelaya &amp; Ituarte, 2004: fig. 2). In addition, none of the teeth in  Neolepton is grooved, and  Neolepton has strong posterior lateral teeth in both valves, which are not discernible in  Cyamiidae . Another difference arises in the degree of development of the external ligament, which is small in  Neolepton and is equally projected at both sides of the umbones (Salas &amp; Gofas, 1998; D. Zelaya, personal observation), in contrast to the large ligament present in  Cyamiidae, which is longer posteriorly. Regarding the anatomy, adult specimens of  Neolepton (unlike cyamiid species) lack the byssus groove and functional byssus glands. In addition,  Neolepton lacks tentacles at the posterior part of the mantle margin and lacks the peculiar follicular epithelium characteristic of  Cyamioidea (Ituarte &amp; Presta, 2017; D. Zelaya, personal observation). All this evidence pleads for the exclusion of  Neolepton (and, consequently, the  Neoleptonidae) from  Cyamioidea . The additional molecular information obtained as part of the present study also supports this hypothesis, at the same time confirming its placement in Veneroidea.</p></div>	https://treatment.plazi.org/id/03BE87C80E3F5227514EFCCD459EF21E	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Zelaya Marina Güller, Diego G.;Ituarte, Cristián	Zelaya Marina Güller, Diego G., Ituarte, Cristián (2020): Filling a blank in bivalve taxonomy: an integrative analysis of Cyamioidea (Mollusca: Bivalvia). Zoological Journal of the Linnean Society 190: 558-591
03BE87C80E3E5226515CFEBB44FEF7B5.text	03BE87C80E3E5226515CFEBB44FEF7B5.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Basterotiidae Cossmann 1909	<div><p>Basterotiidae Cossman, 1909</p><p>Even when this family was described, the genus  Basterotia had generally been included in  Sportellidae and was thus regarded as a  Cyamioidea (e.g. Thiele, 1934; Chavan, 1969; Vokes, 1980; Coan, 1999). Despite that, and based on morphological, anatomical, ecological and molecular evidence,  Basterotia was recently moved from  Cyamioidea to  Galeommatoidea (Campbell, 2000; Giribet &amp; Distel, 2003; Taylor et al., 2007; Goto et al., 2011; Oliver, 2013), in which they appear as a clade (Goto et al., 2012).</p></div>	https://treatment.plazi.org/id/03BE87C80E3E5226515CFEBB44FEF7B5	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Zelaya Marina Güller, Diego G.;Ituarte, Cristián	Zelaya Marina Güller, Diego G., Ituarte, Cristián (2020): Filling a blank in bivalve taxonomy: an integrative analysis of Cyamioidea (Mollusca: Bivalvia). Zoological Journal of the Linnean Society 190: 558-591
03BE87C80E3E522652E4FF114282F0BA.text	03BE87C80E3E522652E4FF114282F0BA.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Bernardinidae Keen 1969	<div><p>Bernardinidae Keen, 1969</p><p>Coan (1984) redescribed and properly figured  Bernardina bakeri Dall, 1910, the type species of  Bernardina, considering this family as belonging to  Cyamioidea . However, this species has a hinge plate and ligament that are not in agreement with those described above for cyamioideans, but closely resemble those present in  Neolepton (compare Coan, 1984: figs. 2a, 2b with Salas &amp; Gofas, 1998: fig 1, 2 or Zelaya &amp; Ituarte, 2004: fig. 2). In fact, Bieler et al. (2010) regarded  Bernardinidae as a synonym of  Neoleptonidae . Contrary to  Neolepton species,  B. bakeri has massive anterior (instead of posterior) lateral teeth. This difference could justify considering  Bernardina as a different (valid) neoleptonid genus. However, as stated by Salas &amp; Gofas (1998), the study of living specimens of  B. bakeri is needed to confirm its correct systematic position.</p><p>The same hinge morphology as  B. bakeri is present in  Bernardina margarita (Carpenter, 1857) and  Psephis salmonea Carpenter, 1864 (figured by Coan, 1984: figs 4a, 10a, b, respectively). Morton (2015) provided detailed anatomical information for the last of these species (referred under the genus  Neolepton). In general, the anatomy of that species closely resembles that of  Neolepton species (properly described by Salas &amp; Gofas, 1998). However,  Bernardina salmonea differs clearly by having a byssus gland and byssus groove that remain well developed in large specimens (absent in the adults of  Neolepton) and by the fact that brooding specimens show the abfrontal cells of the ctenidial filaments greatly glandularized(a condition thus far not observed in any  Neolepton species). The last condition seems to be related to the fact that  B. salmonea brood their embryos in the ctenidia, whereas in  Neolepton concentricum (Preston, 1912) and  Neolepton cobbi (Cooper &amp; Preston, 1910) the larvae overgo their entire development attached to the external shell margin (Zelaya &amp; Ituarte, 2004 and Ituarte &amp; Presta, 2017, respectively). These anatomical and reproductive differences provide additional evidence to suggest that  Bernardina is a distinct genus of  Neoleptonidae .</p></div>	https://treatment.plazi.org/id/03BE87C80E3E522652E4FF114282F0BA	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Zelaya Marina Güller, Diego G.;Ituarte, Cristián	Zelaya Marina Güller, Diego G., Ituarte, Cristián (2020): Filling a blank in bivalve taxonomy: an integrative analysis of Cyamioidea (Mollusca: Bivalvia). Zoological Journal of the Linnean Society 190: 558-591
03BE87C80E3E522652E4FA2F44F1F443.text	03BE87C80E3E522652E4FA2F44F1F443.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Turtoniidae Clarke 1855	<div><p>Turtoniidae Clarke, 1855</p><p>For a long time,  Turtoniidae was regarded as a family of  Cyamioidea (Chavan, 1969; Vokes, 1980; Ponder &amp; de Keyzer, 1998). After studying the anatomy, reproductive biology and shell morphology of  Turtonia minuta (Fabricius, 1780), the type species of the genus on which  Turtoniidae is based, Ockelmann (1964) concluded that this species corresponds to Veneroidea. Mikkelsen et al. (2006) found Turtonidae to be placed outside Veneroidea in all morphological studies they performed, but it was consistently shown to be a member of  Veneridae in all their molecular studies. Consequently, the authors proposed that it should be considered as a subfamily in  Veneridae:  Turtoniinae . The molecular studies by Combosch et al. (2017) support its placement in Veneroidea.</p></div>	https://treatment.plazi.org/id/03BE87C80E3E522652E4FA2F44F1F443	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Zelaya Marina Güller, Diego G.;Ituarte, Cristián	Zelaya Marina Güller, Diego G., Ituarte, Cristián (2020): Filling a blank in bivalve taxonomy: an integrative analysis of Cyamioidea (Mollusca: Bivalvia). Zoological Journal of the Linnean Society 190: 558-591
03BE87C80E3E5223515CFD294117F05F.text	03BE87C80E3E5223515CFD294117F05F.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Galatheavalvidae Knudsen 1970	<div><p>Galatheavalvidae Knudsen, 1970</p><p>The family was diagnosed by having an internal shell, completely covered by the middle mantle fold; the presence of a single (inner) demibranch; a ventrally displaced anterior adductor muscle; two permanent mantle margin openings (inhalant– pedal and exhalant); and a well developed foot, with byssus. Additional characters reported for  Galathea holothuriae Knudsen, 1970, the only species thus far known of this genus, include the absence of teeth in the hinge plate and tentacles along the posterior part of the ventral margin, and the presence of a peculiar ‘dorsal brood pouch’, connected with the mantle cavity and extending beyond the shell. Although the superfamilial placement of this family was not determined by Knudsen (1970) at the time of erecting it,  Galatheavalvidae currently appears listed under  Cyamioidea by Bieler et al. (2010), a placement that appears improbable considering the above-mentioned morphological and anatomical characteristics. Alternatively, Bieler &amp; Mikkelsen (2006) regarded  Galatheavalvidae as  Galeommatoidea . Huber (2010, 2015) followed this superfamilial placement, but considered Galatheavalvinae to be a subfamily of  Galeommatidae .</p><p>SPORTELLIDAE: A FAMILY WITH UNCERTAIN AFFINITIES</p><p>From Thiele’s (1934) classification to the most recent classifications of bivalves (e.g. Ponder &amp; de Keyzer, 1998; Bieler et al., 2010; Huber, 2010), the  Sportellidae were always considered as cyamioideans. However, the concept of  Sportellidae has varied greatly throughout time. In this regard, and as mentioned before, the genus  Basterotia Hörnes, 1859 was included in  Sportellidae for a long time, although it is currently considered as a different family of  Galeommatoidea . Knowledge about the species that remain at present regarded as  Sportellidae appears mostly to be restricted to shell morphology (Coan, 1999).  Sportella dubia (Deshayes, 1824), the type species of the genus (and the type genus of the family), is a fossil. Consequently, the diagnostic (reproductive, molecular and anatomical) characters used in the present study to define  Cyamioidea cannot be studied in that species. The hinge of the specimen described and figured by Deshayes (1824) does not agree with those of  Cyamiidae and  Gaimardiidae . Ponder &amp; de Keyzer (1998) figured a living specimen of ‘  Sportella sp. ’ as having pedal, inhalant and exhalant apertures, the pedal completely papillate, the exhalant projected in a siphon and with ‘well developed tentacles around the posterior inhalant and exhalant apertures’. Furthermore, this figured specimen shows the presence of a long foot, for which Ponder &amp; de Keyzer (1998) described the presence of functional byssus gland(s?) and byssus groove in adults. The presence of a completely papillate pedal aperture and such a long foot are characters not observed in any other cyamioid genus. Some other living species were attributed by different authors to  Sportella, although most of them were subsequently transferred to other genera, such as  Ensitellops,  Fabella,  Neaeromya,  Paramya and  Pseudopythina (all of them currently regarded as  Galeommatoidea). The reproductive characteristics of other living species still grouped in  Sportella have never been investigated. The information available at present does not allow us to draw a conclusion on whether  Sportellidae corresponds (or not) to  Cyamioidea .</p><p>FOCUSING ON  CYAMIIDAE: A CASE OF CONSERVED LINAGES OR A FAMILY LESS DIVERSIFIED THAN PREVIOUSLY THOUGHT?</p><p>Ponder (1971) pointed out that anatomy is the most useful character for determining the generic relationships of  Cyamioidea . To date, anatomical information is known for a relatively reduced group of cyamiid species, as follows:  Cyamiocardium chuanisinense,  Cyamiocardium crassilabrum,  Cyamiocardium dahli,  Cyamiocardium denticulatum,  Cyamiocardium domaneschii,  Cyamiocardium namuncurense,  Cyamiocardium rotundatum,  Cyamiocardium yeskumaala (Soot-Ryen, 1951, 1957, 1959; Passos &amp; Machado, 2014; Urcola &amp; Zelaya, 2018; present study),  Cyamiomactra problematica (Ponder, 1971),  Cyamium antarcticum (Ponder, 1971; present study),  H. laminifera (present study),  J. foveolata (present study),  Perrierina taxodonta (Ponder, 1971),  Ps. cardiformis (Pelseneer, 1903; present study),  Ps. franki (Zelaya &amp; Ituarte, 2009; present study),  Ps. inexpectata (present study),  Pt. georgiana (present study) and  Reloncavia chilenica (Soot-Ryen, 1957, 1959). Considering these species, no major anatomical differences appear among members of  Cyamiocardium,  Cyamiomactra,  Perrierina,  Cyamium,  Heteromactra,  Pseudokellya,  Ptychocardia and  Reloncavia to justify their generic separation. Instead, the characters previously regarded as distinctive at the generic level failed to separate groups when considering the intrageneric variability (such as, for instance, the variability observed in the relative size of the demibranchs or the degree of development of the posterior series of tentacles among different species of  Cyamiocardium), whereas other ‘differences’ seem to have originated in the state of preservation of the studied material; for instance, the byssus groove of  Cyamiocardium, which, contrary to the ‘absence’ mentioned by Soot-Ryen (1951; for  Cyamiocardium denticulatum) is present in that genus (Urcola &amp; Zelaya, 2018; present study). Consequently, anatomy does not help to separate most of the genera of  Cyamiidae considered in the present study.</p><p>Thiele (1934) and Chavan (1969) differentiated the genera of  Cyamiidae based on the general shell outline and shell sculpture, as follows:  Cyamiomactra subtrigonal and smooth;  Cyamium transversely elongated and smooth;  Kingiella ovate (longer than high) and with strongly radially sculptured;  Perrierina,  Legrandina,  Cyamiocardium and  Pseudokellya roundish to ovate, smooth or radially ribbed; and  Ptychocardia oblong (higher than long), sculptured with numerous radial folds, some of them strong and producing undulations in the ventral margin. Undoubtedly, Engl (2012) followed this distinction when he placed  Pseudokellya georgiana in  Ptychocardia again. The above-mentioned shell characters seem to be inadequate for a distinction of these genera, because some  Cyamiocardium species are subquadrate or rhomboidal ( Cyamiocardium chuanisinense,  Cyamiocardium denticulatum and  Cyamiocardium namuncurense), and some species currently regarded under  Cyamiomactra are not subtrigonal or smooth (e.g.  Cyamiomactra chilensis Ramorino, 1968 and  Cyamiomactra falklandica Dell, 1964). Considering shell outline and shell sculpture,  Heteromactra should be regarded as a synonym of  Cyamium and not of Cymiomactra, as currently considered (e.g. Lamy, 1906, 1910, 1911, 1917; Chavan, 1969). In a similar manner, Zelaya &amp; Ituarte (2009) interpreted the existence of a continuum in the shell outline and sculpture of  Pseudokellya species, ranging from the rounded and weakly radially sculptured  Ps. cardiformis to the rhomboidal and strongly radially sculptured  Pt. georgiana, and also including the ovate and smooth  Ps. franki .</p><p>The number, morphology and arrangement of hinge teeth, ligaments and their supports have been (and still remain at present) used as (some of) the main morphological characters for delimiting genera of bivalves. However, and surprisingly, only two different hinge conformations are recognized when regarding the  Cyamiidae considered in the present study. One conformation is present in  Cyamium (as redescribed herein),  Cyamiocardium,  Cyamiomactra,  Heteromactra,  Reloncavia,  Perrierina and  Legrandina, the last two taxa with additional ‘crests’ along the dorsal margin, although these were interpretated as secondary acquisitions by Ponder (1971); in fact, these may be poorly developed in some species, such as  Legrandina harrisonae Powell, 1935 and  Perrierina matai Fleming, 1948 . The second conformation is present in the hinge of  Pseudokellya and  Ptychocardia . This low degree of variability in the overall architecture of the hinge exhibited by cyamiids could reflect: (1) that the general hinge conformation (and the anatomy of the soft part) have remained unchanged (‘conserved’) among different cyamiid genera; (2) that the hinge conformation (and anatomy) experienced phenomena of parallelism/convergence among different cyamiid genera; or, more probably, (3) that the generic diversity of  Cyamiidae is considerably lower than previously thought, with several of the genera that are currently regarded as distinct being synonyms. The previous proposals by Lamy (1917) to consider  Cyamiocardium as a synonym of  Cyamiomactra and by Ponder (1971) to regard  Cyamiomactra as a subgenus of  Cyamium support the last hypothesis. However, the currently available molecular information is not sufficient to be conclusive about this issue; further taxa and markers need to be studied.</p><p>DISCREPANCIES OF THIS STUDY WITH PREVIOUSLY PROPOSED SCHEMES</p><p>The present study reveals that  Cyamiidae and  Gaimardiidae are closely related families. This grouping contrasts with the most traditional point of view, which considered them as belonging to two different superfamilies: Gaimardioidea and  Cyamioidea (Thiele, 1934; Chavan, 1969; Vokes, 1980). Although Ponder (1971) had previously suggested that these taxa were closely related (he considered them as two subfamilies of  Cyamiidae), this proposal did not receive acceptance by subsequent authors. In fact, in most recent studies both taxa were regarded as belonging to different superfamilies (e.g. Bieler et al., 2010; Lemer et al., 2018).</p><p>The difference of the scheme proposed in the present study from that of Ponder (1971) is not restricted to the taxonomic rank assigned to  Cyamiidae /Cyamiinae and  Gaimardiidae /Gaimardiinae, but also concerns the placement of  Kidderia . According to Ponder (1971),  Kidderia is closer to  Cyamium than to  Gaimardia (consequently, he regarded it as a Cyamiinae), whereas according to the present study,  Kidderia is more similar to  Gaimardia than to  Cyamium, consequently being included in  Gaimardiidae and not in  Cyamiidae . The family placement for  Kidderia proposed in the present study is in agreement with the previous usages by Odhler (1924), Thiele (1934) and Dell (1964); the placement in all these studies was based upon the characteristics present in the type species of  Kidderia and the closely similar  K. bicolor . However, the possibility that some other species currently placed under  Kidderia could correspond to  Cyamiidae cannot discarded, becuse  Kidderia is presently considered as ‘possibly polyphyletic’ (Ponder, 1971).</p><p>Another point of discrepancy with the previous literature concerns the placement of  Pseudokellya . This genus was largely regarded as belonging to  Lasaeidae /  Kelliidae (Galeommatoidea) (e.g. Chavan, 1969; Vokes, 1980; Engl, 2012). The information obtained in the present study (namely, the presence of a follicular epithelium surrounding the oocytes and embryos and the presence of tentacles at the posterior end of the mantle border) allows us to confirm that  Pseudokellya is a  Cyamioidea, as previously reported by Thiele (1934) and Zelaya &amp; Ituarte (2009).</p><p>CONCLUDING REMARKS AND FUTURE PERSPECTIVES</p><p>The present study reveals  Cyamioidea as a monophyletic superfamily of bivalves. Members of this superfamily vary greatly in shell morphology and anatomy. However, all of them share a reproductive character: the presence of a follicular epithelium, which appears first at the early stages of oogenesis and persists until larvae are fully developed, brooded within the female gills. The follicular epithelium is unusual among bivalves and, in fact, it is not known for any other bivalve family; thus, it is valuable to define  Cyamioidea . Curiously, and for the first time among marine bivalves, a reproductive character proves to be more informative than shell morphology and anatomy for the definition of a superfamily.</p><p>Despite the restricted significance of morphological and anatomical characters for defining  Cyamioidea, they appear to be useful for delimiting families within this superfamily:  Cyamiidae and  Gaimardiidae, with the latter previously regarded as belonging to a different superfamily (Gaimardioidea).  Neoleptonidae, previously regarded as cyamioideans, are definitively removed from this superfamily and reallocated into Veneroidea based on the molecular evidence obtained in the present study. The placement of  Sportellidae in  Cyamioidea requires confirmation.</p><p>As part of the present study, we confirm that  Gaimardia and  Kidderia can be reunited in  Gaimardiidae and that  Cyamiocardium,  Cyamium,  Heteromactra,  Pseudokellya,  Ptychocardia and  Reloncavia belong to  Cyamiidae . Within the latter group, we also tentatively place  Cyamiomactra and  Jukesena, although some anatomical and molecular evidence suggests that they might, in fact, correspond to a different family of  Cyamioidea . Likewise, the relationship of  Legrandina and  Perrierina to  Cyamiidae requires further study.</p><p>The synonymy or, alternatively, the eventual validity and relationship among different (sub)genera of  Cyamiidae and  Gaimardiidae also need to be investigated in more detail, particularly the affinities of  Eugaimardia and  Progaimardia with  Gaimardia and of  Costokidderia and  Cyamionema with  Kidderia . In contrast, cyamiids now appear to be defined mainly upon shell characters. The hinge conformation, usually considered as a key character for defining genera of bivalves, does not provide a clear distinction among  Cyamiocardium,  Cyamiomactra,  Cyamium,  Heteromactra,  Legrandina,  Perrierina and  Reloncavia or between  Pseudokellya and  Ptychocardia . The general shell outline and shell sculpture, currently used to define these genera, prove to be more variable than previously thought, and the same characteristics appear in different taxa. Furthermore, the molecular studies performed in the present study, although providing full support for the entire superfamily, do not resolve the relationships among (sub)genera. All these facts imply either that several of these names are currently being used ambiguously or that some of them correspond to synonyms. The addition of more anatomical and molecular information for other species (in particular, molecular studies involving faster-evolving genes and further taxonomic sampling) appears crucial for an adequate re-evaluation of the validity of the different genera. We prefer to refrain from introducing nomenclatural changes or including new synonymy for these taxa until further study has taken place.</p></div>	https://treatment.plazi.org/id/03BE87C80E3E5223515CFD294117F05F	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Zelaya Marina Güller, Diego G.;Ituarte, Cristián	Zelaya Marina Güller, Diego G., Ituarte, Cristián (2020): Filling a blank in bivalve taxonomy: an integrative analysis of Cyamioidea (Mollusca: Bivalvia). Zoological Journal of the Linnean Society 190: 558-591
