Revised systematics of Palaeozoic ‘ horseshoe crabs’ and the myth of monophyletic Xiphosura Author Lamsdell, James C. text Zoological Journal of the Linnean Society 2013 2012-12-18 167 1 1 27 http://dx.doi.org/10.1111/j.1096-3642.2012.00874.x journal article 10.1111/j.1096-3642.2012.00874.x 0024-4082 5292231 CHASMATASPIDIDA CASTER & BROOKS, 1956 [= DIPLOASPIDA SIMONETTA & DELLE CAVE, 1978 ] Diagnosis: Dekatriata with the tergite of somite VII retained as a dorsally visible microtergite; tergites of somites VII–X dorsally fused into a buckler; buckler underlain by ventral plate.