Epicodakia Iredale, 1930
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https://doi.org/ 10.5281/zenodo.5392295 |
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persistent identifier |
https://treatment.plazi.org/id/039087F4-FFDA-6A3F-1019-FD67FE28D584 |
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treatment provided by |
Marcus |
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scientific name |
Epicodakia Iredale, 1930 |
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Genus Epicodakia Iredale, 1930 View in CoL
Epicodakia Iredale,1930: 390 View in CoL . Type species: Epicodakia consettiana Iredale, 1930 View in CoL (earlier name Lucina minima Tenison-Woods, 1876 View in CoL , preoccupied by L. minima Roemer, 1836 View in CoL ) (original designation).
Talocodakia Iredale, 1936: 273 View in CoL . Type species: Talocodakia kennethi Iredale, 1936 View in CoL (original designation).
DIAGNOSIS. — Shells small to medium sized, longer than high, regularly ovate in outline with low umbones. Sculpture of 20 to 75 regularly spaced, narrow or broad radial ribs, rarely bifurcating, crossed by commarginal lamellae producing low, rounded, often closely-spaced scales on summits of ribs, (basketwork or snakeskin effect). Ligament external, short. Hinge plate narrow; 2 cardinal teeth in each valve, the larger usually bifurcate, with single anterior and posterior lateral teeth in RV and paired in LV. Anterior adductor scars medium long, detached for about 1/2 of length. Shell margin smooth or finely denticulate.
REMARKS
There has been much confusion concerning use of this generic name, especially since Iredale (1930) included E. gunnamatta Iredale, 1930 (a Ctena species ) within his concept of the genus. Furthermore, Chavan (1969: fig. E3.9b) figured Ctena divergens as an example of Epicodakia and provided only a small, poorly reproduced image (fig. E2.2) of the outside of E. consettiana . Also, the various southern Australian species that have been included within Epicodakia appear to be a heterogeneous group of lucinids. In order to clarify the concept of Epicodakia , we include here a description and illustrations of the type species.
The type species, E. consettiana , has less prominent sculpture, with a larger number of radial ribs than some of the other species we have included in the genus, but other features including overall shell shape, ligament, hinge teeth and muscle scars are similar.
Ctena species can be distinguished from Epicodakia by their more circular outline, the strong, bifurcating and intercalating radial ribs and the short ligament that is deeply inset into hinge plate.
We include the following IWP species in our concept of Epicodakia : Lucina obliqua Reeve, 1850 , China; E. sweeti ( Hedley, 1899) see below; E.nodulosa n. sp.; Lucina minuata Deshayes, 1863 , Réunion; E. neozelanica Powell, 1937 , New Zealand. The southern Atlantic species Epicodakia falkandica Dell, 1964 has little resemblance to the type species and should be excluded from the genus.
Epicodakia consettiana Iredale, 1930 View in CoL ( Figs 17 View FIG ; 18A View FIG )
Lucina minima Tenison-Woods, 1876: 30 View in CoL (non Lucina minima Roemer, 1836 View in CoL ).
Epicodakia consettiana Iredale, 1930: 391 View in CoL (replacement name for L. minima View in CoL ).
TYPE MATERIAL. — Syntype of L. minima Tenison-Woods, 1876 (Tasmanian Museum and Art Gallery, Hobart; see May 1903: 114, fig. 12).
TYPE LOCALITY. — Badger Island, Tasmania.
MATERIAL EXAMINED. — Australia. Western Port, Victoria ( NMV). — Edithburgh, South Australia ( SAM). — Houtman Abrolhos Islands, western Australia ( BMNH).
DISTRIBUTION. — Southern Australia.
DESCRIPTION
Small (L to 25 mm), white, sometimes yellow internally, oval, longer than high, not inflated. Sculpture of many (up to 75) narrow, low, closely-spaced radial ribs crossed by regularly-spaced commarginal lamellae, forming small scales on ribs ( Fig. 17C View FIG ). Lunule narrowly lanceolate, not sunken and slightly asymmetrical, with RV extending into LV. Ligament short, external. LV with 2 cardinal teeth, anterior larger and bifid, posterior tiny; two posterior and two anterior lateral teeth; RV with two cardinals, anterior small, posterior larger, and usually bifurcate, with single anterior and posterior laterals. Anterior adductor scar short and detached from pallial line for about 1/2 length. Pallial line entire. Shell margin outside pallial line glossy, edge finely denticulate.
REMARKS
Codakia perobliqua Tate, 1892 and Talocodakia kennethi Iredale, 1936 View in CoL are possibly conspecific with E. consettiana View in CoL but further analysis of shell variation is needed to confirm this.
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.
