Annals of the South African MuseumThe Museum, 1991 - Natural history |
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Page 5
... concentric , radial ornament to area subordinate to transverse ornament , hinge myophorian ; 2 hinge tri- gonian , area with radial ornament , at least in nepionic stages ; 3 = shell ovate , marginal carina obsolete , beaks prosogyrous ...
... concentric , radial ornament to area subordinate to transverse ornament , hinge myophorian ; 2 hinge tri- gonian , area with radial ornament , at least in nepionic stages ; 3 = shell ovate , marginal carina obsolete , beaks prosogyrous ...
Page 24
... concentric flank costae of the nepionic stages pass on to the area , whereas the longitudinal furrow persists almost to maturity and is situated closer to the escutcheon than the flank . The flanks are ornamented with coarse nodes that ...
... concentric flank costae of the nepionic stages pass on to the area , whereas the longitudinal furrow persists almost to maturity and is situated closer to the escutcheon than the flank . The flanks are ornamented with coarse nodes that ...
Page 43
... concentric costae anteriorly meeting fewer , broader , subvertical posterior costae in a chevron ; ornament may be replaced by concentric growth rugae in maturity . Discussion Although this taxon is included by many within the synonymy ...
... concentric costae anteriorly meeting fewer , broader , subvertical posterior costae in a chevron ; ornament may be replaced by concentric growth rugae in maturity . Discussion Although this taxon is included by many within the synonymy ...
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Common terms and phrases
Algoa Basin Anditrigonia antecarinal sulcus anterior commissure anterolateral shoulder anteroventrally Apiotrigoniinae Bivalvia broad chevrons coarse commissure comprises convex Cooper Cretaceous Description Shell Diagnosis elongate escutcheon carina faunas finely crenulated flank costae flank ornament genus growth rugae growth striae Hauterivian Hoepen holotype inflated anteriorly interspaces Iotrigonia irregular Kobayashi kraussi Kitchin lanceolate large maximum length Lateral view lectotype left valve longitudinal groove Megatrigoniacea moderately Myophorella Myophoriidae Nakano neotype nepionic stages Neumayr nodate Nototrigoniinae opisthogyrous beaks Paranditrigonia paratypes persisting to maturity phyletic Port Elizabeth Museum posterior set posterodorsal margin Poulton Pterotrigonia radial costellae radial ornament Rennie respiratory margin Reyes ribs right valve rostrate shallowly concave shell length Skwarko smooth South African Museum Steinmanella herzogi Goldfuss straight strongly oblique subconcentric subfamily Sundays River Superfamily synonymy Tashiro Tithonian transverse costellae transverse ornament Trigonia Trigoniacea Trigoniinae trigonioid tubercles Type species Upper Valanginian V-shaped Valanginian vau Sharpe ventral margin ventricosa Krauss Yaadia