Bivalves from the latest Jurassic-earliest Cretaceous hydrocarbon seep carbonates from central Spitsbergen, Svalbard Author Hryniewicz, Krzysztof krzysztof.hryniewicz@nhm.uio.no Author Little, Crispin T. S. earctsl@leeds.ac.uk Author Nakrem, Hans Arne krzysztof.hryniewicz@nhm.uio.no text Zootaxa 2014 2014-09-02 3859 1 1 66 journal article 4900 10.11646/zootaxa.3859.1.1 d866af6f-cbcd-47f4-a4f3-1499c1789ae3 1175-5326 4930112 24FCAAE1-AB7C-4FAD-8698-D0C9F12400EC
TABLE 2. The main characters distinguishing Cretaxinus gen. nov. from other large chemosymbiotic thyasirid genera.
GenusCretaxinus gen. nov.Axinus J. Sowerby, 1821Thyasira Lamarck, 1818Parathyasira Iredale, 1930Conchocele Gabb, 1866
ShapeSubtriangularSubhexangularOvate to ovate- polygonalOvate to ovate diamond-shapedSubquadrangular
OrnamentCommarginal growth linesCommarginal wavy ridgesCommarginal growth linesCommarginal growth linesCommarginal growth lines
LigamentThick and external with small internal partPartially externalVariably sunken, short to mediumSunken, short to mediumThick, sunken and long
Character of posterodorsal marginPs, (sms), no auricle, wide and deep escutcheonPs, no auricle, small escutcheonPs, sms, auricle, variable escutcheonPs, no auricle, ill- defined escutcheonPs, (sms), no auricle, no escutcheon
Adductor muscle scarsAAMS smaller and weaker than PAMSAAMS ≈ PAMSAAMS larger than PAMSAAMS larger than PAMSAAMS much larger than PAMS
ReferenceThis studyPayne & Allen 1991; Löffler et al. 2006; Oliver & Holmes 2007Payne & Allen 1991; Oliver & Killeen 2002; Oliver & Holmes 2006; Rodrigues et al. 2008; Zelaya 2009Iredale 1930; Payne & Allen 1991; Oliver & Killeen 2002; Zelaya 2009Kamenev et al. 2001; Okutani 2002