TABLE 2. The main characters distinguishing Cretaxinus gen. nov. from other large chemosymbiotic thyasirid genera.
Genus Cretaxinus gen. nov. Axinus J. Sowerby, 1821 Thyasira Lamarck, 1818 Parathyasira Iredale, 1930 Conchocele Gabb, 1866
Shape Subtriangular Subhexangular Ovate to ovate- polygonal Ovate to ovate diamond-shaped Subquadrangular
Ornament Commarginal growth lines Commarginal wavy ridges Commarginal growth lines Commarginal growth lines Commarginal growth lines
Ligament Thick and external with small internal part Partially external Variably sunken, short to medium Sunken, short to medium Thick, sunken and long
Character of posterodorsal margin Ps, (sms), no auricle, wide and deep escutcheon Ps, no auricle, small escutcheon Ps, sms, auricle, variable escutcheon Ps, no auricle, ill- defined escutcheon Ps, (sms), no auricle, no escutcheon
Adductor muscle scars AAMS smaller and weaker than PAMS AAMS ≈ PAMS AAMS larger than PAMS AAMS larger than PAMS AAMS much larger than PAMS
Reference This study Payne & Allen 1991; Löffler et al. 2006; Oliver & Holmes 2007 Payne & Allen 1991; Oliver & Killeen 2002; Oliver & Holmes 2006; Rodrigues et al. 2008; Zelaya 2009 Iredale 1930; Payne & Allen 1991; Oliver & Killeen 2002; Zelaya 2009 Kamenev et al. 2001; Okutani 2002
persistent identifier: http://table.plazi.org/id/7EE7FCD39F3AE30604E6FCE4FA272A0D
Published as part of Hryniewicz, Krzysztof, Little, Crispin T. S., Nakrem, Hans Arne (2014). Bivalves from the latest Jurassic-earliest Cretaceous hydrocarbon seep carbonates from central Spitsbergen, Svalbard. Zootaxa 3859 (1): 1-66. DOI: 10.11646/zootaxa.3859.1.1 on page 36